Today I’m going to provide some clear evidence of the benefits to increasing your ISO to help reduce grain. Sounds crazy, I know, but this works, and after this post I think you’ll believe me.
I have been meaning to do this for a while, as although I’ve talked about Exposing to the Right and how increasing the ISO can help to reduce noise, I do realize that this is counterintuitive. I also received an email from listener Matthew Wells, as follows:
In several podcasts, you mention how you will shoot higher ISO levels by exposing to the right to brighten the image to reduce the visible noise. Could you put together a short video for your Youtube channel to show your methods for doing this? I have tried to play with the idea a little without success so far.
Matthew Wells via email.
Thanks very much for your suggestion Matthew. I decided to do this as a straight post rather than a video so that I can provide some examples that you can open and look at directly, and I think this format will help more for now.
Why Take Control?
So, the first thing I want to do is explain why I take control, with an example you can try for yourself really easily. All you need is something white, and something black, or a very dark color. Literally, a large piece of paper or a bedsheet is fine for the white thing, and a dark coat will work for the dark thing, and this works best if the things you find are not too glossy or shiny.
In my studio, I have both white and black backgrounds on a pulley system so that I can change the background for my photographs quickly. I have a roll of black paper that we won’t use for this, and a roll of white paper, and a roll of felt cloth, that we will use. You can see what I mean in this photograph, with the black background extended part way so that you can see them both.
Black and White Backgrounds
White is Grey!
Here now, is a photograph of the back of my camera, in LiveView, and set in Aperture Priority mode with Auto-ISO turned on and no Exposure Compensation dialed in. There are a couple of things that I want you to look at. Firstly, while noting that I’m pointing the camera at a sheet of white paper, look where the data of the histogram is falling. All three channels are only one third from the left side. This means as you can see from the photo that the white background would be recorded as grey, not white.
White is Grey!
The other thing that I want you to look at is that the shutter speed has been set to 1/160 of a second and the ISO is 4000. I set the aperture to f/5.6 myself, and the camera has automatically selected the other settings.
Black is Grey Too!
Now let’s look at another photo, and the only difference between the two images is that I’ve drawn down the black felt background, as you can see in front of the camera. I didn’t touch the camera other than to half-press the shutter to display the exposure details. Look at what’s happened to the color of the background in LiveView. Nothing! The black background is also grey, and the histogram shows us that it’s very similar, if not almost identical to the grey in the photograph of the white background.
Black is Grey Too!
We can also see that the settings have changed. The shutter speed has been increased to 1/15 of a second from 1/160 and the ISO has gone from 4000 to 12800. Using the Exposure Calculator in my Photographer’s Friend app I can quickly see that the camera has changed the exposure from 17 2/3 EV to 16 EV, a difference of one and two-thirds of a stop. Just to quickly walk through this, the shutter speed change is 3 and a third of a stop, and the ISO change is one and two-thirds of a stop, so if we deduct the ISO change from the shutter speed change, we get one and two-thirds.
I could have left Auto-ISO off to make that easier to understand, but I also wanted to show how the camera would want to increase the ISO instead of taking the shutter speed much longer.
So, what does this tell us? Well, for one thing, it tells us that our cameras are still pretty stupid when it comes to metering certain scenes and setting its exposure. This is why I almost always shoot in Manual mode. You can use Exposure Compensation too, and which method you use is completely up to you, but I find using Manual easier, mostly because I’ve been doing it so long, but also because as the size and position of the various elements in your frame change, the exposure will also change, so you have to continuously adjust the Exposure Compensation, especially when you are Exposing to the Right, which we’ll discuss shortly.
This is extremely important when photographing things like the Red-Crowned Cranes that we shoot on my Japan Winter Wildlife Tours. These are a white bird against a white background when they are on the snow, but when they fly, the background is much darker, and as you’ve seen, the camera always tries to make a dark scene brighter and a bright scene darker.
So if you dial in up to plus two stops of Exposure Compensation, which is required to make the snow and white bird actually white, then recompose and start to include a darker background, the camera will increase its exposure to lighten the dark background, and the white bird essentially becomes completely over-exposed.
A Real-World Example
Here is a screenshot of Capture One Pro showing two photographs that I shot as I explained this to a participant on this year’s tour. To prove the point, I put the camera into Aperture Priority mode and pointed my camera down so that only white snow was in the frame. This is how I set my exposure in Manual Mode, because the cranes are also mostly white.
Exposure Example
Keep in mind that to set my exposure in Manual Mode, all I do is increase my exposure while looking at the caret on the meter, until it’s between +f and+2 stops over zero. For brightly lit snow, it’s closer to +1 and for snow on an overcast day, it’s usually around +2 stops. Now that I’m shooting with the mirrorless EOS R camera, I have a live histogram and can actually just keep on increasing the exposure until the data on the histogram is almost touching the right shoulder, but without this feature, I used to just take a test photo, just like the one you see on the left here. As long as it’s white, but not over-exposed, I know that I’m then good to go, and because the bird is white, like the snow, and under the same light, I am then free to just shoot away until the light changes again.
In an automatic exposure mode though, such as Aperture Priority in our example, as you can see, as soon as I recompose to include an even slightly darker background, the camera tries to lighten up the scene, and my whites start to get over-exposed. So, if you want your whites to be white, not grey, you really must take control of the exposure by locking it down in Manual mode, or you have to change your Exposure Compensation every time you recompose.
I’ve added a few bits of markup to the screenshot to point out a few key things. First, notice on the left that I have +2 stops of Exposure Compensation dialed in, and I’m in Aperture Priority mode for this example. Also, note how the shutter speed changes from 1/500 of a second for the correctly exposed shot and drops to 1/200 of a second as the camera tries to compensate for the darker background. It would probably make more sense to use shutter priority for birds in flight, but as an example, it doesn’t really matter. The point is, the exposure runs off as we recompose.
Also note that the red that you see over the bird and the snow are not markup, that is the Exposure Warning in Capture One Pro. You can see that this is turned on also by the fact that the icon in the toolbar is yellow. This is grey when the Exposure Warnings are turned off.
Higher ISOs are Less Grainy with ETTR
So, let’s move on to the benefits of increasing the ISO rather than being afraid to, for fear of introducing grain. Most people have the idea that increasing the ISO causes grain in your images, and of course, that is true, if you leave the exposure up to the camera, because the camera is generally going to underexpose your images. Here is an example with two photos that I shot as a test, just of some ornaments and a little metal EOS R that I got as part of the release campaign here in Japan.
ISO Example
If you click on the image to open it up in the lightbox, even at the web size you’ll be able to see the visible grain in the right image, which I shot with the camera’s built-in meter at zero, exactly where the camera thought the exposure needed to be. It was indoors late afternoon, and because the ISO performance is so good on the EOS R, I had to increase it to 51200 for you to really see the grain.
For the left image though, to prove my point, I used Aperture Priority mode again, with +2 stops of Exposure Compensation dialed in, as I’ve circled in red on the left of the screenshot. You can see underlined in red, that both images were shot at 51200 ISO and the +2 stops images shutter speed was 1/125 of a second, exactly two stops slower than the right image, which was shot at 1/500 of a second.
Comparison
Here now, is a 100% crop of each of the images from the above screenshot, so that you can check the details. As you can see, despite them both being shot at ISO 51200, the grain visible in the +2 stops version, which is I should emphasize, exposed to the right, is virtually undetectable, compared to the image at the camera’s recommended metering, which is very grainy.
ISO 51200 Camera Zero Metering @ 100%
ISO 51200 +2 Stops @ 100%
Again, if you click on the images to view them in the Lightbox you’ll get the best view of the detail, but the difference I’m sure you’ll agree is huge. Note too that although in comparison, the lighter image may appear too bright, it’s actually only slightly over-exposed, with the highlights just clipping slightly. If you wanted to darken it back down again, you could use the Highlights sliders or a tone curve, and you’d still get a cleaner image by exposing to the right like this, then darkening it back down to suit your needs.
Another Take On This
Another take on this, which is perhaps easier to understand from a shooting workflow perspective, is the fear element that generally prevents people from increasing the ISO. Imagine you are in a situation where the light is low, and you are already forced to shoot your image at 12800 ISO, at 1/125 of a second to avoid subject blur, and you need an aperture of f/8 for sufficient depth of field. The camera is metering at zero, with the information in the histogram way over on the center decreasing down the left side. The actual ISO will depend on your camera, but many people start to shy away from shooting higher than around 3200, some even as low as 1600. For me, as I get used to the EOS R’s ISO performance, I would probably not have gone higher than 12800 in the field, because I hadn’t yet done these tests. On my 5Ds R bodies, I tried to avoid going above 6400 ISO, based on tests.
ISO 12800 Camera Zero Metering @ 100%
As you can see from this image, with its histogram embedded for reference, there is a little bit of grain starting to creep in. Still incredible for a 12800 ISO image at zero metering, but you can see the grain.
+1 Stop Increase
So, what do you? Most people would shoot at 12800 or whatever your own personal soft-ceiling is, and be afraid to increase the ISO any more for fear of introducing any more grain, but wait! To get your histogram data over to the right, in this hypothetical example, our only option is to increase the ISO further. Here is another image in which I’ve increased the ISO by one stop to 25600.
ISO 25600 +1 Stop @ 100%
This image is double the ISO at 25600, but the grain is actually less than the 12800 ISO image because the ISO increase has made the image brighter. You can see from the histogram, which I screen-captured from the full sized image, not the cropped version, that although it’s more to the right than the previous images, there is still a gap.
One More Stop!
For this next image, I increased the ISO yet another stop, to 51200. This is actually the lighter image of the pair that we just looked at in my first example. and as you can see from the histogram, we are now exposing to the right. There is a small gap, but that’s Capture One Pro giving us a little back. In the camera, the specular highlights were just starting to over-expose, so this is as far as I would like to take this image exposure-wise.
ISO 51200 +2 Stops @ 100%
A Few Tweaks
You can see that increasing the exposure with the ISO has actually reduced the amount of grain visible in the photograph. The darker parts of the image are now starting to suffer from a little bit more grain, but if you really had to push your ISO this far, you could do a few tweaks such as adjusting the levels and curves to darken down the dark areas a little, which helps to mask the grain that does creep in there.
ISO 51200 +2 Stops Tweaked @ 100%
And I haven’t even touched the noise removal options. They have been set at the default settings all along. So, as you can see, although I know it’s counter-intuitive and probably goes against everything you’ve been taught, if increasing the ISO helps you to expose to the right, then the brighter image will almost always have less grain in it than the lower ISO image, if the lower ISO image is already very high.
I should add at this point, that for lower ISOs, where you really can’t see any grain anyway, there is something called ISO invariance, that we looked at in Episode 520, which basically means that you can shoot according to your camera’s meter at lower ISO, and then increase the brightness in post if necessary, and you still won’t see any grain, because there is nothing in the base image for you to amplify. What I’m talking about today is more for higher ISOs, which is generally the area that starts to get people nervous. It’s that fear that I’m hoping I can help you to break through with this post.
My ETTR Workflow
I’m sure that part of Matthew’s original question was also referring to how I actually adjust my exposure, so I’d like to add a little more detail on this before we close. As I mentioned earlier, I pretty much always shoot in Manual Mode, though occasionally I do shoot in Aperture Priority and turn on Auto-ISO, and use Exposure Compensation to Expose to the Right. My thought process is similar in either shooting mode.
Aperture
I start usually by selecting my Aperture, as this directly affects my depth of field, and that is often one of my most important decisions as I start to set my exposure. Once I have set my aperture to something appropriate, i.e. a small number like f/2.8 for a wide aperture and shallow depth of field, or a larger number like f/11 for a smaller aperture, and more depth of field.
Shutter Speed
I generally then set my shutter speed in Manual Mode. I will select a faster shutter speed, like 1/500 to freeze a moving subject or a faster shutter speed of 1/1600 of for fast moving subject or birds in flight. Or I might select a slower shutter for a landscape, or even use a Neutral Density filter to slow down the shutter speed even more for some of my landscape work. If I am in Aperture Priority mode I often control the shutter speed by setting a minimum speed in the camera settings, just to help the camera to avoid going too slow, but getting faster is generally not a problem in these cases.
ISO
Finally, I adjust my ISO. It’s actually my ISO most of the time that I use to actually adjust and fine tune my exposure. This is why I am really enjoying the new Control Ring on the front of the Canon RF Lenses, because I have this set to adjust my ISO, so I can now really easily adjust it while looking through the viewfinder and keeping my eye on the live histogram.
With the live histogram I literally just adjust my ISO until I see the data on the histogram just about start touching the right side. For landscapes, even with my older DSLR bodies, I used to turn on LiveView and do this on the LCD.
Highlight Warnings
It’s also important to turn on Highlight Warnings on your camera so that you can see when you do start to get over-exposed and pull it back a little. I will often use a very small amount of flashing or the “blinkies” as an indication that I’m right where I need to be exposure-wise, but once a larger area starts to blink, I pull the exposure back a little.
RGB Histogram
And it’s also important to use the RGB histogram rather than the black and white brightness histogram, because the brightness histogram is an average of all three channels, and doesn’t always show you if one color is becoming overexposed before the others, and it can cause a nasty blotchiness in your colors if you allow one color to blow-out.
Camera Meter in Manual Mode
Also, note that even when I am in Manual Mode, I still reference the camera’s meter reading. People often think you are flying blind in Manual Mode but that is not the case. When you half-press the shutter, the meter still kicks in and shows you where it thinks the light levels are on the meter, so for example when I am adjusting for the white snow, I can see the caret moving on the meter scale, and use that to see when my settings result in my exposure being two stops over.
If it’s not a white snow scene, I will just guess at where the caret should be on the meter scale, based on the balance of light and dark objects in the scene. If it’s literally 50/50, then the meter might be at zero, or perhaps just a little over to get my histogram data over to the right.
Note too that I’m always talking about the right-most data, not all of the histogram data. The rest of the data represents your mid-tones and shadows, and can, depending on your scene, extend all the way over to the left shoulder. Occasionally you might shoot a scene with very high contrast, and find that even when exposing your highlights to the right, your shadows can start to spike up the left side. That’s when you might consider merging multiple images in an HDR photo, but personally, I have not had to do that for many years, while using my ETTR techniques.
Thanks for the question Matthew, and I hope this was useful for all that stop by and take the time to read or listen to this episode.
Complete Namibia Tour & Workshop
Before we do finish, I’d like to mention that we’re at the time when we need to start finalizing the numbers for my 2020 Complete Namibia Tour & Workshop This is an epic trip that encompassed landscape, culture and wildlife and we next year will be my sixth visit, and the tour just keeps getting better and better, so I’d love for you to join me there. Please check out the details at https://mbp.ac/namibia2020 and drop me a line if you have any questions. If you visit this post after the 2020 tour closes for bookings, check our Tour & Workshops page for a list of currently available tours.
The Zone System has kind of fallen into the shadows as digital enables us to see our images instantly, and view information like the invaluable histogram even before we release the shutter, but The Zone System is still a useful tool, and something worth taking the time to understand whether you use Ansel Adams’ original exposure techniques or not.
I’m sure most of you have heard of The Zone System, and some of you will already have a good understanding of what it means and how to use it, so this might not be new to you, but it’s a great topic to explore, and I find it totally relevant as a follow up to my recent episode about creating camera profiles for the Sekonic L-758D Digital Master light meter.
First, I’m going to explain what The Zone System is all about and intersperse my own take on its applications within digital imaging. We’ll also take a look at how you can use a light meter to evaluate your options in the field as you create your images and evaluate your images on the computer, both of which can be invaluable to help you understand exposure.
The Zone System
The Zone System was developed by Ansel Adams with Fred Archer way back in 1940. It is a system to map the various tonal regions or luminance of objects in any given scene to enable the photographer to reach the optimal exposure during the capture of the image, and the developing and printing of the negative.
OK, so in the last paragraph the word optimal is my take on this, but Adams’ goals were the same. It’s not so much about accurate exposure, because there really isn’t one. Adams phrases this as photographs being interpretations of the original subject values and subjective departures from reality.
The Zone System was most useful as initially intended, to control the exposure of individual sheets of film, rather than rolls of film, because the development and print process could be adjusted for each negative based on shifts applied during the initial exposure of each sheet of film. There are of course limitations on the developing process when using roll film, as all images on each roll are developed in exactly the same way.
Ironically, in the digital age, one could argue that the Zone System is more applicable again, as we go back to being able to adjust our processing of each frame individually, including during the digital printing process.
The Zone System basically maps tones into eleven ranges of values from pure black to pure white. How people associate these tonal ranges to numerical values seems to vary, but I’ve split two ranges into equal parts, as Adams did, and created a reference chart on which we’ll base parts of this discussion, including a slightly modified description of what each zone meant within The Zone System (below).
The Zone System
As you can see (above) the eleven zones are marked in roman numerals, from 0 (zero) to X (10). The reason for the roman numerals was to differentiate the zone values from exposure values (EV) or any other arbitrary numerical scale on the light meter which are usually written in regular Arabic numerals. I’ve added the two scales, from 0 to 255 for RGB color values, and 0 to 100 for Lightness values, and I’ll talk about how to use these ranges to evaluate your images in Photoshop later.
Definition of the Zones
Adams further defined groups of zones in the follow ways. Zones 0 through to X (10) represents the entire range of tones, from “full black to pure white”. Zones I (1) through IX (9) are what Adams referred to as the “dynamic range”, and this represents the darkest to lightest tones that can be considered “useful”. Zones II (2) through VIII (8) were referred to as the “textural range” which represents tones that convey a sense of texture and recognizable substance.
Although I’ve seen heated arguments as to whether or not a Zone is equal to one stop of EV or Exposure Value, Adams himself clearly states that this is how he intended the zones to be used in his book The Negative in which he fully describes The Zone System in glorious detail. If you still want to know more about this subject after today’s post, I strongly recommend that you pick up a copy and read it for yourself. In fact, it’s just a great read for any photographer, so I highly recommend it either way.
Now, in practice, we’ll find that as the dynamic range that our cameras can record increases, strict use of The Zone System requires that we will have to move away from thinking of each zone as one stop of exposure, or, simply use more zones, keeping the zone to EV stop relationship. But, as of 2015, most cameras have a dynamic range of about 12 stops.
As we found in my recent discussion about creating profiles for the Sekonic L-758D light meter, I actually have a measured range of 11.9 stops on my Canon EOS 5Ds R, and DxO Mark have it at 12.4 stops, so we’re at around 12 stops of dynamic range in digital terms. This is the full range from full black to pure white, and I consider almost that entire range to be useful, so it’s a bit wider than Adams’ definition, but in practice I’ve found that even now, thinking of each zone as a stop of exposure works fine.
Exposure “Stops”
Just in case this talk of “stops” has you scratching your head, this is how we talk about steps of exposure, controlled by three main camera settings, the aperture, shutter speed and ISO. We can also change exposure with filters such as neutral density filters, which we talked about in episode 391.
Modifying your camera’s exposure by one stop you could for example change your aperture from f/5.6 to f/8, or from f/11 to f/16, with some of the main full stops of aperture being f/1, f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22 and f/32.
Because the aperture value represents the area of a circle, they are approximations of a sequence of numbers that are the power of the square route of 2. Although it can be confusing at first, this means that the smaller the number, the larger the area of the circle, and therefore the more light passes through the aperture and onto our camera’s sensor, increasing the exposure. Less is more.
This also has the effect of increasing or decreasing the depth of field of the scene or subject being photographed. For more information on how that works, check out episode 132 or episode 437 in which we discussed hyperfocal distance.
Shutter speeds are easier to grasp, because you simply halve or double the time to change up or down by a stop. One stop faster than 1/500 of a second is 1/1000 of a second and one stop slower is 1/250 of a second. A stop slower again is 1/125 but then the next stop slower is 1/60, so it’s not exactly half. In fact, the real shutter speed for 1/125 of a second is 1/128, and a stop slower should be 1/64. They are mostly adjusted slightly, but there’s no reason to be concerned about this. You get used to the actual numbers used.
The ISO range can also seem a little confusing, but again you get used to it. Film years ago was much slower, or less sensitive to light, but these days, although some digital cameras start at the expanded ISO 50, most start from ISO 100. To increase the ISO in full stops, you just double the value for each subsequent ISO, so one stop more sensitive than ISO 100 is 200. The next full stop is ISO 400, then 800, 1600, 3200, 6400 and so on.
A full “stop” increase or decrease in aperture, shutter speed or ISO will have the same effect on your exposure. For example, an exposure of f/8 for 1/250 of a second at ISO 200 can be made one stop brighter by changing our aperture from f/8 to f/5.6, one stop larger, or we could make our shutter speed twice as long by changing it from 1/250 of a second to 1/125 of a second, or we could make our ISO one stop more sensitive by changing from 200 to 400.
Identify Your Mid-Tone
OK, so back to The Zone System; Ansel Adams wanted a way to evaluate the exposure levels of a scene, so that he could place certain tones at certain places and calculate from that exposure whether or not the other tones in his scene would be too dark or too bright, and adjust the exposure if necessary to protect those extremes in contrast.
As I said, this also carried over into the development process, which was adjusted as necessary as well, but we won’t go into detail on that here as it’s not relevant for digital. Again, if you want to understand this more Ansel Adams’ The Negative should be your first stop (no pun intended).
You would start metering your scene by identifying the tone that you would place in Zone V (5). In black and white terms this is called the mid-gray or middle-gray, but in color photography, let’s call it the mid-tone, as it’s referred to on my light meter. The beauty of this first step is that if you can’t easily identify what in your scene is a mid-tone, if you are outdoors with the same light falling on your scene as where you are, you can simply take a meter reading of an 18% gray card to get this exposure value.
There are lots of conversations around the web regarding whether cameras are calibrated to 18% gray, 12% gray, or 12.5, 13% or 14% etc. During the creation of my camera profile using my Sekonic L-758D light meter and the Sekonic (X-Rite Munsell Color) Exposure Profile Target II, I first took meter readings with both incident and reflected light from the 18% gray side of the target.
Sekonic L-758D Creating Profile – Metering the Light – Incident
I then set my Canon EOS 5Ds R camera to the exact same settings that my Sekonic L-758D light meter measured and the exposure scale on the camera indicated that there was zero discrepancy from what the camera’s spot meter measured. The meter reading was exactly the same, and this tells me that Canon is using 18% gray.
This can vary depending on the light source, but this result is enough for me to proceed with this article using 18% gray as the middle-gray, and you’ll also learn why I don’t think this is totally important in the age of digital, and with the understanding that Ansel Adams adjusted exposure as necessary, we also know that it wasn’t something to get too bent out of shape about, even during Ansel Adams’ day.
Start With Your Mid-Tone
So, the starting point for setting your exposure with The Zone System was to identify your mid-tone or middle-gray. You can do this by viewing your scene, and taking meter readings from a number of subjects that you think would be close. Adams would look for something that he felt would spoil the photograph if it was allowed to become too dark, although he does talk about using an 18% gray card in The Negative as well, as a way to get an accurate exposure, if that is what you require.
When you first take a meter reading from your scene, the light meter will interpret the luminance value as though the substance being measured was a middle-gray. Although you can change this functionality, the meter will often assume that the first reading you take is the mid-tone, and start to record subsequent measurements in relation to this mid-tone, or middle gray.
I generally like to start my metering with an incident light measurement when I’m outdoors, assuming I’m in the same lighting conditions as the scene I’m photographing. This of course would not work if I was in shadow photographing a brighter area not under the same cover.
The Beauty of the Light Meter
The thing that I absolutely love about using a light meter though is, because they are measuring the luminance of a subject, unlike a camera’s built in metering system, they don’t try to convert everything to a mid-gray. If I take an incident meter reading of the light falling on a snow scene, then take a reflective meter reading of the snow itself, the snow will be around two stops brighter than the incident meter reading. I’d get the same two stop difference by taking a reflective meter reading from an 18% gray card as the base.
If this isn’t making much sense, get a piece of white paper and a piece of black paper, or anything that is black, but both need to be big enough to fill the frame of your camera. Put the camera in Aperture Priority mode an set the aperture to say f/5.6 and ensure that exposure compensation is at zero.
Fill the frame with the white paper, and take one photograph. Then, put the black object in the same place as the white one, under exactly the same light, and take a second photograph without changing the camera settings. Then, on the back of your camera, flick between the two images that you just shot. You’ll most likely find that they are both exactly the same. They’ll be a mid-gray. To actually make them black and white, you’d need to add +2 stops of exposure compensation when shooting the white paper, and -2 stops of exposure compensation when shooting the black paper.
Play the Metering Game
As another learning exercise with my light meter, I like to play a game where I measure the light falling on a scene with the incident meter, which is the method using the white dome on the light meter, and then press the Memory button on the meter to record that base measurement, and then try to meter something else in the scene that is as close to this incident meter reading as possible. You can do this in your living room, or outside, it doesn’t matter.
This helps to train your eye to find the mid-tones in your scene, and can actually be quite satisfying when, for example, you meter the light source, then find something that is within just a third or two thirds of a stop brighter or darker than the incident light measurement. A little geeky, maybe, but this is the sort of thing that I’ve done over the years to hone my skill in estimating exposure, and that is a big part of what this is all about.
Find Your Extreme Luminance Values
Back to metering your scene in the field now, it’s not important that your metered mid-tone is absolutely the middle-gray, as we’ll adjust this anyway, based on the following part of the exercise. You now need to identify and measure the lightest and darkest parts of your scene. If you are following along with me here with your own light meter, figure out how to memorize the tones that you are measuring.
The Sekonic L-758D can memorize up to 9 meter readings, by pressing the Memory button on the left side, underneath the spot metering lens. Once I have my incident light measurement saved, and probably one or two reflective measurements from what I thought were the mid-tones in the scene, I’ll start to measure and save the luminance values for the lightest and darkest parts of the scene.
If the sun is in your scene, there isn’t much point in taking a meter reading from the sun’s disk itself, and you also need to be careful not to look directly at the sun through the light meter’s spot meter viewfinder, as many of these are magnified so you could damage your eyes. In The Zone System, the sun would also be considered a specular highlight, falling in zone X (10), so we wouldn’t try to prevent it from over-exposing anyway.
Do take a reading though, for example, of bright cloud near to the sun, especially if it is important that there is some detail recorded in these areas. The same goes for the darkest parts of the scene. Record some values from foreground rocks for example, that might have their shadow side facing you. These might be very dark.
Protect Your Shadows?
If you find that the shadow areas in your scene are very dark, you have to make a decision as to whether or not the detail and texture in the rock is important. In the original Zone System, if your shadow areas were more than three stops darker than your mid-tone, you would start to lose the appearance of substance or texture in these areas.
This means for example, if your mid-tone Zone V (5) with the aperture set to f/8 was metered to give you a shutter speed of say 1/125 of a second, and your dark foreground rocks were metering at 1/8 of a second, that’s four stops darker, putting the rocks in Zone I (1), and that’s where The Zone System is defined to have slight tonality but no texture. If you were to go to 1/4 of a second that would put your rocks in zone 0 (zero) so they’d be completely black, with no visible texture.
As we’ll see later, this is one key area where modern digital imaging has exceeded the boundaries of The Zone System as defined by Ansel Adams, because it was based on old film, which had a much smaller dynamic range. This means that now we would need to either remap the zones to not mean one stop of EV per zone, or do what I do, which is to learn how far I can push my exposure, and work to new boundaries, but still keeping the Zone System in mind.
So, if you do need to protect your shadow areas for some reason, say they are even darker and you feel that there will be no detail there, even with the dynamic range of your camera, which we’ll talk about shortly, then you have to consider brightening up your image.
Protect Your Highlights for Digital
The major difference with the film based Zone System and how it is applied to digital imaging, is that in the film days, it was much easier recover detail in bright or over-exposed highlights than it was to recover lost shadow detail. In The Negative, Adams says “The low values (shadow areas) are controlled primarily by exposure, while the high values (light areas) are controlled by both exposure and development.
In digital imaging, once we’ve over-exposed our highlights, there is no way to get any detail back, so we have to do the reverse, and protect our highlights when shooting digital. If we look again at the graph showing data from my 5Ds R during the creation of my camera profile (below) we can see that the drop-off of information in my shadows is a much shallower curve than my highlights, so there is a much better chance of me saving my shadows, than salvaging detail from blown highlights.
Sekonic DTS Adjusted Profile Graph
Digital Place and Fall
If, like me, you use a technique called ETTR or Expose To The Right, this means that you set your exposure so that your highlights are almost or even just touching the right side of the histogram, and then let the mid-tones and shadows fall where they will. Adams uses the term Place and Fall when describing the Zone System, meaning that you find your mid-tone or Zone V (5) exposure tones, and then let the shadow and highlight detail fall where they will, unless you have to adjust exposure to protect either of the extremes.
You can do exactly this in digital as well, and with today’s image quality, your images won’t suffer much for this, but because of the way digital images are recorded, we get more and more grain as the mid-tones and shadow areas get darker and darker, so you will get better image quality by recording your image as brightly as possible, and this is exactly what ETTR does.
Even if my darkest shadows are only in Zone V (5) I still exposure for the highlights, and if necessary, I can darken the image down in post, getting the same exposure that I would have if I’d exposed with those mid-tones in the middle of the histogram, but I have much cleaner shadow areas using this technique. I place my highlights as close to the right as possible, and let the rest of the image fall where it will.
I use this technique pretty much across all of my photography, and I love the results I’m getting. Note too that even when my shadow areas seem incredibly dark, I am still getting detail from these areas, fully utilizing my 12 stops of dynamic range, as we’ll see in a moment. We can consider this digital place and fall.
In Meter Dynamic Range
If you recall from episode 501 in which we created the camera profile for my Canon EOS 5Ds R and transferred it to the Sekonic L-758D light meter, the reason I was so excited about this is because it enables me to show the dynamic range of my camera right there on the meter, so I can see if the luminance values in my scene fall inside the capability of my camera to record without over or underexposing my highlights and shadow areas.
In practice, because I’ve been using a meter for around 15 years, mostly as a learning and teaching tool, I don’t meter my scenes in the field all that often, especially as we can see the information we are capturing right there in the histogram, but I am really excited about having my dynamic range displayed right there on the L-758D light meters exposure scale, both to work with students, but also just to easily check the extremes of contrast in my scenes as I evaluate my options.
Evaluating Your Scene
Let’s now jump into Photoshop and evaluate a photograph that I made on my Hokkaido Landscape Photography Adventure Tour in January 2015. We’ll open the original photograph, straight out of the camera, and then I’ll show you the final image after converting it to black and white, and bringing out all the lovely detail from the tetra pods in the foreground, that I knew would be recorded, but really could not see in the image as I viewed it through the viewfinder or on the LCD display on my camera.
Photoshop Info Panel Options
If you don’t have your Info panel displayed in Photoshop, hit the F8 key or click Info under the Window menu. Then click the button in the top right of the Info panel and select Panel Options… and you’ll see this dialog. I have my First Color Readout set to RGB Color and my Second Color Readout set to Lab color. Then, from the Photoshop tool bar select the Color Sampler Tool, which you’ll see when you click the Eyedropper Tool.
Now, as you roll your mouse over the image, you’ll see the numbers in the Info Panel change, showing you the values of the tones that you are rolling over. These numbers correspond to the ranges of numbers that I added to The Zone System chart that we looked at above, so you if you click on that image, then drag it to your desktop, you can open it as a reference.
The other cool thing about the Color Sampler Tool, is that when you click it, it adds a little marker to the image and you can see all of the Lightness values of the tones you click on. The L in Lab, as in the Lab Color that we selected earlier stands for Lightness, and ranges from 0 to 100.
Once you are at zero, you are recording pure black and at 100, you are recording pure white. These are the absolute extremes of The Zone System. After you’ve clicked to record a sample, if you right click it, you can change it to Lab if you prefer to reference the 0 to 100 scale, which I personally prefer for this exercise. Before you start to sample tones, change the Sample Size to 31 by 31 Average in the top toolbar, so that you aren’t sampling too small an area.
You’ll need to click on the below image to see these sample marks, and maybe even drag it to your desktop and open it on your computer to see, but in the middle of the image, you’ll find my first sample, which we can see in the top right has a Lightness of exactly 50, which is smack in the middle of Zone V (5). This is my mid-tone for this scene.
Photoshop Lab Samples
If you look at the second easier to see Sample 2 (above) you’ll see that this Lightness value is 99. It’s just a hair under 100, where all detail is lost. That’s the brightest part of the scene, and very close to being totally blown out. Down in the bottom left corner, you’ll see Sample 3 (above) which has a Lightness value of 1. This is the darkest shadows I can record and still have a chance of recovering any information.
Looking at this image, if you have your display calibrated and the correct Brightness, you really shouldn’t be able to see much, down there in the bottom left corner. That’s how it looked through the viewfinder and on my LCD display in the field as well. I went ahead and made this exposure though, because I knew that these values were close, but not totally out of my dynamic range.
Converting to Black and White
If you know my work, you’ll probably know that I’m a huge fan of black and white photographs, and even as I shot this image, I knew that I would take it into Silver Efex Pro 2 and convert it to black and white as my final image. I’ve done tutorials on Silver Efex Pro in the past, so we won’t look at that today, but I wanted to point out one important feature of Silver Efex Pro that I use before saving every image I convert to black and white with it.
You’ll need to click on the image (below) and open up your browser window as wide as possible to see this full size, but if you look down in the bottom right corner, you’ll see 11 small boxes, ranging from black to white, numbered 0 to 10. You’ve guessed it. This is a dynamic indication of The Zone System, right there in Silver Efex Pro. (Remember that once you’ve clicked the image to view it larger, you’ll need to place your mouse over the image to stop it advancing to the next image automatically.)
Zone X (10) Indication
As you can see (above) when I roll over Zone 10, there are some diagonal lines that have appeared over the brightest part of the sky where the sun’s rays are radiating from. If I wanted to I could have brought these down a little in my final image, but I actually consider these silver linings on the clouds as specular highlights, and decided to leave them this bright.
As long as I know which areas are very bright, I can make the decision as to whether or not I will change the image, and that is the beauty of these Zone System displays. I am though less likely to allow shadows to totally plug up, because blacks tend to print really dark anyway. For this image, when I rolled my mouse over Zone 0 (zero) there were no areas that are totally black. This screenshot shows areas in Zone 1, and they are basically limited to areas of deep shadow, which is exactly how I planned this photo.
Zone I (1) Indication
Finally, once I saved the image and return to Photoshop (below), we can now see the new values from the black and white image, as the Color Sample markers are still in place. My darkest shadows have increased from 1 to 5, my brightest highlights have come down from 99 to 98, and my mid-tone has become very slightly brighter at 53.
Lab Samples from Black and White Image
The important thing to note here as well is that what appeared to be very deep shadows in my original image actually contained a lot more texture and detail that you might have thought, especially if you’d seen this on the back of the camera as I shot this image. It’s at times like this that many people start to think of HDR to increase the dynamic range, but as I’ve mentioned in the past, I rarely do HDR, as I don’t believe it’s necessary.
If HDR is a creative avenue for you, then that’s fine, but if you don’t particular enjoy the process, then hopefully some of what we’ve covered here will help you to rely a little more on your cameras ability to capture a full range of tones.
Just to clarify as well, before we finish, the image I’ve used in this example was shot with my 5D Mark III, not the 5Ds R. The 5D Mark III actually had very slightly less dynamic range than the 5Ds R, so we’d be looking at a very similar example anyway.
Conclusion
OK, so to wrap this up, I’d like to reiterate that you don’t necessarily need a light meter to make great photographs. I didn’t meter the above scene in the field. I relied totally on the histogram, which I do believe is an essential tool, especially when we are pushing the extremes of our cameras’ dynamic range.
I also find it very important to turn on highlight warnings on my camera. The highlight warnings are based on the in camera JPEG, so I tend to keep my Picture Style set to Neutral or Faithful, so as not to change this much, but it’s still an 8 bit JPEG and there is much more detail and information captured in the raw file.
I use the preview as a guide, and sometimes set the exposure so that I’m just starting to blow out my highlights, and then I find that the resulting images are actually just inside the limits, and very usable, right up to a point that would probably have had Ansel Adams rethinking his Zone System as well. If he was still with us though, he would have embraced digital with open arms, and I’m sure he’d be pushing exposure to extremes like this, pulling as much out of the technology as possible.
If you are thinking of buying a light meter, although it’s been on the market for a while now, I can’t recommend the Sekonic-L-758DR Digital Master light meter enough. The ability to create those camera profiles using the Sekonic Exposure Profile Target II takes it’s usefulness to a whole new level, as you can see right there on the meter exactly how your scene maps to your own camera’s dynamic range. If you haven’t already, check out episode 501 for more on that.
The other important feature of the Sekonic L-758D or DR in the US, is that it has a 1° spot meter, which is vitally important for taking accurate readings from your scene. Many other meters have 5° spot meters, which are too wide to really pick out and meter fine details in your scene.
Although the light meter is not 100% necessary today, as I’ve mentioned, I do find them very valuable as a way to learn about exposure, and light, and how it affects our images both in the field and in post processing. I also find the light meter to be a very useful teaching tool, so if you teach photography yourself, it’s also definitely worth considering, and I’ve included a number of exercises today that you can do yourself, so I hope that this whole post has been useful for you.
Following on from our Why Expose to the Right (ETTR) episode a few months ago, I received a question from listener Christopher Pearson, asking how I meter in Manual mode, so today, I’m going to explain my techniques for metering in manual mode.
First of all, I want to explain that I leave my camera in the Evaluative Metering mode now. For long time listeners, you may remember that long ago I used to use center-weighted average metering, but I stopped that years ago, because I now just like to see what the camera “thinks” about a scene, and Evaluative metering allows the camera to think for itself a little more. I know people that use spot metering as well, which works well, but I haven’t used spot metering in years either, as I just don’t feel there’s a need for it.
I should also explain that just because the camera is set to Manual mode, that doesn’t mean that the camera stops metering. As you look through the viewfinder in Manual mode, the little caret that indicates where the camera think the exposure is, still works, so for example if I have my camera set for too short an exposure compared to how the camera sees the scene, the caret will be below zero on the Exposure Level Indicator scale, and if I have my exposure set too high, the caret will be above zero.
This means that when shooting in Manual mode, we aren’t flying blind. We still have the benefit of seeing where the camera thinks we should be, and that allows us to quickly make adjustments based on what we see in the scene. I’ve spoken about this before, but just to recap with an example, but the most common manual mode compensation that I do, is when photographing in the snow.
Metering for a Snow Scene
The first thing I do when I am shooting a snow scene, is point the camera down slightly, and fill the frame with snow, as you can see in this example image (below). I usually start at ISO 100, and then set my aperture for the depth-of-field that I want to shoot at, and then start to adjust my shutter speed, until the meter indicator shows me that I am 2 stops over zero.
I aim for plus two stops, because I know that is how I need to exposure for whites to be white, and not grey. Remember, the camera wants to make everything 18% grey, so without this manual compensation, the photo would look more like this example (below) and we don’t want that.
Once I have my exposure locked down like this in Manual mode, I know that my snow is going to be beautiful and white, and the red-crowned cranes that I shoot are also going to be perfectly exposed, even with texture visible in their beautiful black feathers. If I left this up to the camera, the white of the cranes would be grey, not white, and their black feathers would be so dark there’d be no texture in those areas at all.
Also, in case you are wondering why I wouldn’t just use plus two stops of Exposure Compensation in Aperture Priority mode, that’s because the birds can move from their white snow background, to a very dark background in an instant, as we see in this next photo (below). And when that happens, instead of the camera underexposing the whites, trying to make them grey, it sees all that dark and increases the exposure trying to make the black grey, and the white bird goes super-nova.
Soft Arched Wings
So remember, for snow scenes, if you fill the frame with snow, and adjust your exposure so that the camera thinks you are two stops over exposed, you will be in good shape. For very dark scenes, you would usually do the opposite, but as I explained in the Why Expose to the Right episode, you may not always want to do that, but if you missed that episode, I suggest you go back and check that out instead of me covering that again today.
What About Other Scenes?
With other scenes, I really don’t meter the subject as such. I literally look through the viewfinder, estimate how much of the frame is bright and how much is dark, and adjust the exposure to what I think will be close, then take a test shot and check the histogram. The estimation process takes a bit of getting used to, but the more you do it, the easier it gets. I’m usually either spot on, or just 1/3 or 2/3 of a stop under or over at tops.
I leave my metering mode in evaluative. I don’t use spot metering, because even with spot metering the camera still wants to make everything 18% grey, so I find that it takes longer to find my ideal exposure than adjusting based on a guestimate, and then shooting the test shot. I would still want to shoot a test shot even when using spot metering, and still may have to fine tune, so I just leave my camera in Evaluative Metering mode now, as I mentioned earlier.
Which Parameters to Change?
To arrive at my ideal exposure, with the data almost or just touching the right side of the histogram, I might change any of the three parameters in the exposure triangle. I generally start with the Aperture because I usually want to control depth-of-field first, then I set a low ISO of say 100 if there is plenty of light, and then adjust my exposure with the shutter speed. If it turns out that my initial ISO setting was a little too low, I might revisit that and increase it some more so that I can get a shutter speed that suits my subject matter.
Exposure Triangle
In the earlier example I used a shutter speed of 1/640 of a second, but for flying birds I actually like to go a little faster, so I might go to ISO 200 for a 1/1250 of a second shutter speed. Also, if there is a bit of patchy cloud around, I might find that I have to adjust the exposure every so often, and I usually do this with the ISO, so I might increase from ISO 200 to 400 while the cloud is there, then back to 200 when the sun comes out again.
How you handle this will depend on your camera. Canon cameras generally have an ISO button to select the setting you are going to change, then you just turn a dial to change it. Some Nikon cameras bury the ISO setting a little further into the menus, which can make this a bit of a pain, so you’d need to figure out the best way to make these changes for your own equipment.
No Need to be a Manual Snob
Young Himba Man
I also want to note that I’ve become so used to shooting in manual, that I have a hard time going back to Aperture Priority mode, because it actually takes me more time to adjust my exposure with exposure compensation than it does to adjust my manual settings.
I do wish however, that I was better with Aperture Priority, as it makes more sense in some situations. When I’m doing street photography for example, I am now using Aperture Priority with Auto ISO, and I’m getting used to it, but it’s hard for me.
I forced myself to use Aperture Priority for example in Namibia earlier this year, when we visited the Himba people. We were shooting in a variety of lighting conditions, and it just made more sense. For this photo of a young Himba man sitting in the doorway of his hut, my ISO was set to 400, for a 1/60 of a second exposure, with an aperture of f/3.5.
The camera would have chosen the shutter speed of a 1/60 of a second because I was shooting at 64mm with my 24-70mm lens, so it’s trying to use my focal length as my shutter speed to avoid camera shake. I’d of course set the aperture, because I was in Aperture Priority, and the camera selected ISO 400 because that’s what I needed to maintain the minimum shutter speed. I also see from the EXIF data for this shot that I had dialed in – 2/3 of a stop in Exposure Compensation, because the subject is predominantly dark. Had I not dialed in that compensation, the young man would have been too bright, probably over-exposing the highlights on his forehead, and his two sticks would also have been over-exposed.
Use a Handheld Light Meter
One last tip that I want to relay, because I found it very useful, is that if you have or can borrow one, a light meter can really help to understand exposure. Mine is a quite old Minolta light meter that is now discontinued. I think if I was to go out and buy one now, I’d go for the Sekonic L-478DR light meter, because that’s the one Zack Arias swears by.
Of course, you don’t really need a light meter now that we have the histogram on the camera, but I do still use mine sometimes in the studio. Especially when I’m setting lights up at a customers home or office. I can plug my Profoto Air Remote right into my meter, and then trigger the lights with the meter to get my readings. That’s going off topic though. The point I wanted to make here is that when I first got a meter, I was already shooting digital, but just spent a lot of time taking incident light readings, which is where you use the little white dome to read the level of light falling on your scene, and just seeing if that was close to my estimates.
Even without a camera, I would carry the meter around with me and just meter stuff. I also used the spot meter which is where you look through the little viewfinder in the meter to take a reflective reading of the light bouncing off of your subject. It can really help you to hone your exposure estimations just doing this, and also when you are out shooting. Compare how your camera sees the scene with it’s limited artificial intelligence based on stored scenes, and compare that to the raw readings from your hand-held meter. I don’t suggest you buy a meter for this, as you’ll probably never use it, but if you know someone that has one, ask if you can borrow it for a month and meter the hell out of your world for a while. It’s a lot of fun.
Anyway, that’s about it. I wish I could talk more about metering, but really, the histogram is king to me, so I generally start with my guestimate, adjust while viewing the in camera meter, and then take a test shot and check the histogram to ensure that the lightest part of my scene is just up to the right shoulder of the histogram. That’s pretty much it in a nutshell.
Today I’m going to go into detail on why I expose to the right, as I get asked about this a lot. Exposing to the right means adjusting your exposure so that the image data we see in the histogram falls as close to the right shoulder as possible. I’ve touched on this a number of times, but never really gone into detail about the reason, so here we go.
Actually, before we jump into this, I found out last week that images in this Enhanced Podcast not being displayed in iTunes 11 is not a bug, but the way Apple have decided it’s going to be. You have to hold down the Command key on a Mac or CTRL key on a Windows machine, then click the artwork in the little window at the top of iTunes. This will open the Enhanced Podcast viewer, so you can follow along with the images. I’ve also put a page together to help you understand this at mbp.ac/ituneshelp, so do take a look if you’ve been missing the images.
Tanchou Study #7
Firstly, let’s look at why this helps you to create cleaner images, starting with a little background. When I first started shooting with a Digital SLR camera, some 12 years ago now, it was common for people to slightly underexpose the images to give them a little punch. It seemed to make the colors more vibrant. The problem with that, as we’ll see, is that we were inadvertently introducing more noise to the images.
After a few years I started to travel to Hokkaido where I now run my Winter Wonderland tours, and before very long I started to shoot in Manual mode to ensure that I was getting well exposed snow. As you know, camera’s meters still try to expose everything as an 18% or neutral grey, which means if you shoot a snow scene, the camera will under-expose the photo by around two stops of exposure, making the snow look like a muddy grey.
You can use exposure compensation, adding two stops to counter this, but then if the predominantly white Red-Crowned Cranes that I shoot up there move from their white background to a dark background, you’d have to change your exposure compensation from plus two stop to minus two stops to compensate for the now dark background.
For example, one moment I could be photographing something like this photo (right) of a white crane on a white background, and the next moment I could spot another crane flying into the area, on a dark background.
These next two images are screenshots from Lighroom, to show you the histogram as well. You can see that this first image (below left) of a crane on a dark background is predominantly dark, but with a small spike to the right of the histogram representing the white bird. You can also see a gap between the bird and the right shoulder of the histogram, but this is Lightroom giving me an extra stop of exposure to play with. In the camera, this will have been just touching the right side of the histogram. (Click on the images to enlarge for a closer look.)
“Soft Arched Wings” in Lightroom
“Soft Arched Wings” 4 Stops Overexposed
Had I simply raised the camera from the shot of the white crane on a white background though, still with plus two stops of exposure compensation dialed-in, the camera would have seen the dark background and brightened it up to a mid-grey, probably to the tune of around 4 stops, because you need to add 2 stops for white, or reduce by around 2 stops for black. I simulated this in Lightroom by increasing the Exposure by 4 stops, as we can see in this shot (above right).
See here too how the data on the histogram is mainly in the middle, but with the white bird spiking up the right side of the histogram? The data in the middle is what should be the black background, and that should be way over on the left, with the white crane on the right, but not touching the right side of the histogram. If you see this in the field, without knowing what you are overexposing, it’s time to pull your exposure back until the histogram is just before or just touching the right side.
Of course, a crane against a blue sky would be a different setting again, and the size of the crane in the shot changes how much exposure compensation we need too, so you end up fighting a losing battle, or bracketing. Unless you are shooting for HDRs, bracketing just shows a lack of understanding on exposure. I was initially told this by one of my mentors, a Japanese photographer called Hiroshi Yokoyama, a wonderful elderly gentlemen that used to be an Olympic winter sports photographer, and now lives in Hokkaido fulfilling his life’s work. I also heard Ansel Adams say this on a documentary too, so it’s not just me being outspoken here. Well, maybe not…
Why is this Important?
Exposing for whites aside, you probably are still wondering why I’m such a stickler for exposing to the right, even for scenes of average brightness and tonality. You’d be forgiven for thinking that if the scene is similar to a mid-grey, you could leave the exposure up to the camera, but that is not the case. I started exposing to the right intuitively, but after a few years, someone pointed out a great article on Michael Reichmann’s Luminous Landscape web site about Optimizing Exposure. This was actually a follow up from a 2003 essay called Expose Right, and both are well worth a read. The biggest take-away is how cameras distribute the image data when the image is saved to your memory card, which we’ll look at here.
Camera sensors have to convert the light that is captured by the photo-diodes on your sensor to a digital value. Most cameras these days save this data for each pixel with 14 bits of data, meaning we can have up to 65,536 tonal values per pixel. Many cameras at the moment record about 12 stops of dynamic range, some more, some less, and this is the range between a true black and a true white, and with a 14bit sensor, this means we’d have 65,536 tonal values between the two extremes.
Think of this as gradually filling a bucket with water, or even filling a photo-diode on your sensor with light. A totally empty bucket would be zero, or totally black, and then as you pour water into the bucket, or light into the photo-diode, you gradually fill it until you hit the maximum it can hold, which would represent a pure white. Anything after that is just overflow. The white can’t get any whiter, and that pixel is now over-exposed.
Because digital sensors are linear devices, if you double the amount of light that hits the photo-diode, you double the voltage generated by the sensor, or the amount of water that we pour into the bucket. The result is that data is literally halved with each stop or EV (Exposure Value) that is recorded, so the brightest stop of light the sensor can record has to be double that of the second brightest. This means that to use the full 65,536 tonal values across the entire image, we have to half the amount of data that can be used for each exposure value from pure black to pure white. For a 12 stop dynamic range sensor, this means your data is broken up into 12 steps, as follows…
Darkest
—
—
—
—
Mid
Tones
—
—
—
—
Brightest
EV
1
2
3
4
5
6
7
8
9
10
11
12
# Tones
16
32
64
128
256
512
1,028
2,048
4,096
8,192
16,384
32,768
This is why the darker parts of the image are noisier than the brighter parts. The noise is always there, but because we have less data to record the darker areas of our image, the noise is much more visible. I’m sure you’ve noticed that even a nicely exposed image often has a bit of noise in the shadows. This is why.
Exposing an Average Scene
We’ve looked at a white scene, or a dark background with a white subject, and for those scenes, it’s easy to understand why I set the exposure as I did. But what if you shoot a mid-tonal scene? Of course, if you leave the exposure up to the camera, it will record the scene in the middle of the histogram, so you will essentially recording your image with between say 256 and 2,048 tonal values per stop as opposed to between 4,096 and a massive 32,768 tonal values per stop in the brightest four stops of the image, and for a 12 stop dynamic range camera, this would be what is represented by the right-most third of the histogram. Here’s an example of such a histogram, from this shot of a Springbok in Namibia earlier this year (below).
Springbok Shot in Lightroom
See how the histogram data is over in the right third, again though noting that Lightroom is giving me an extra stop here. In the camera, the histogram was right up to the right shoulder. This of course means that despite me shooting this image at ISO 2500, even when viewed at 100% there is very little noise, as we see here (below).
ISO 2500 Springbok photo at 100%
In an extreme case, you might find yourself shooting a very dark subject against a dark background. In the film days, you’d have dialed in maybe a stop or even two stops of negative exposure compensation, to ensure that the scene was recorded naturally dark, remembering that the camera wants to brighten it up to an 18% grey.
Darken Down in Post
To ensure that we record our images with as wide a range of tonal values and as little noise as possible, you would even expose a very dark scene to the right, and then reduce the Exposure of your image in your post processing workflow. I don’t have any examples this extreme, although many of the sand-dune photos from Namibia this year have had the exposure dialed down to some degree. My favorite shot of the camel thorn trees against the sunlit sand dunes at Deadvlei for example was dialed back by half a stop of exposure in Lightroom, to what we see here (below).
Deadvlei Silhouettes
This was according to plan of course. I get the highest quality image possible by exposing to the right, then darken it down in post as much as necessary. Of course, I’m aware that many people think my images are high-key anyway, but that’s because I have my monitor brightness set very low, as part of the calibration process. Many people don’t do this, and that’s why my images seem bright.
The sad fact is though that most people’s images are actually under-exposed because they trust the camera too much, but they never know because they view them on a monitor with the brightness turned up full. Then they print and wonder why the prints are too dark. If this sounds familiar to you, I hope a few pieces of the puzzle are starting to drop into place here.
A New Exposure Mode
Part of the reason I decided to talk about this today was because of a conversation on This Week in Photo a few weeks ago. I’d mentioned shooting to the right, which raised some listener questions. After talking a little about shooting to the right though, we went on to talk about new features that we’d like to see in cameras, and I said that I’d love to see a setting on the camera that allowed you to just keep exposing the image until it starts to blow out, or over-expose.
Ideally we’d be able to set a parameter to tell the camera how much of the scene gets over exposed. For example we might want to stop at 0%, so there are no specular highlights overexposed at all. Or we could set it to say 1%, 3% or 5% etc. as we can now start to blow out the image in the JPEG preview on the camera, but Lightroom gets more detail from the RAW file, so you can go over a little without worrying about it too much.
There are times such as when I’m shooting the snow monkeys, when I actually blow out probably up to 30% or 40% of the scene, because I’m looking for a well exposed monkey, and don’t care too much about the background. It’s often out of focus anyway, and the slice of snow on the same focus plane as the monkeys has a bit of texture, which reduces it’s luminosity to the point that is doesn’t overexpose anyway.
You have to be careful doing this of course, as too much over-exposure can bleed or bloom into the darker areas, messing them up a bit, but for the snow monkeys this doesn’t really happen due to their fur, kind of protecting the highlights around them.
Reverence
What I could see happening is a kind of hybrid Aperture Priority mode, where I tell the camera what aperture I want to use, as that’s my most important setting, but then I also want to control how slow the shutter speed gets, so Auto-ISO would also need to be turned on. I’m already doing this for some of my photography, although I still shoot in Manual mode more than 99% of the time, because I lose too much control in Aperture Priority and exposure compensation drives me crazy.
When using Auto-ISO the camera bases the shutter speed on the focal length, but you can set a minimum shutter speed as well, which is necessary with wildlife as the animals can move around so much that you need a fast enough shutter speed to avoid subject blur. This needs to be opened up a bit though. On my 5D Mark III 1/250 of a second if the fastest shutter speed I can select. This would be fine for the snow monkeys most of the time, but I need faster shutter speed for birds in flight. Ideally I’d like to be able to set this to any shutter speed the camera can use, though I’d probably set it to between 1/500 and 1/1000 of a second for birds in flight, depending on the size of the bird and how much wing movement I want.
All of this though is only relevant if I had the ability to tell the camera to keep on exposing until a certain percentage of the scene got blown out, so I imagine the algorithms would be somewhat complicated, but we already have the ability to create a live histogram in Live View, so the camera could adjust the Shutter Speed, ISO or even Aperture, depending on our settings, to achieve the optimal exposure, which we can already see in the histogram.
This would of course become more difficult for TTL or Through The Lens photography, because there’s no light hitting the sensor like there is in Live View. Once you start to expose the image though, light is hitting the sensor, so assuming I was in Aperture Priority mode, I imagine the camera would need to change the ISO as well as the shutter speed dynamically as it exposed the image, all in as fast a time as 1/1000 of a second.
Stopping the exposure as the image starts to over-expose is already possible with some flash photography though, and that is working at similar speeds, so I know it’s not impossible to do. It’s really just a case of the camera manufacturers spending the R&D dollars or more likely yen, to figure this out for regular exposure and get it implemented. I see a time though when we will expose all scenes to the right for the best quality image, and then the camera might even include a bit of information on the actual tonal values in the scene, and normalize it in post, or even in the camera, but without throwing away all the tonal values that it gained by exposing the image to the right.
Use the RGB Histogram
So, if you don’t already expose to the right, but I’ve convinced you to give it a try, there are a few things that you’ll need to bear in mind as you work. Firstly, if your camera has the ability to display an RGB histogram, turn it on. The standard grey histograms are displaying an average of the Red, Green and Blue channels, and this can give you a false sense of security. Depending on your subject, one of the channels can start to blow out before the others, and it’s sometimes only possible to see this with an RGB histogram.
Don’t Fear High ISOs
Also, if you are going to shoot dark scenes with up to three or four stops brighter exposure, do keep your eye on your shutter speeds. You may need to increase your ISO to achieve a fast enough shutter speed for the scene in front of you.
This shot of a cheetah for example is not a dark scene as such, but it was dark when I shot this. Just minutes before we could only see this cheetah with the lights of our safari vehicle, and there was just enough light from the sun, still below the horizon, for me to be able to get this shot by cranking up my ISO to 12800.
Cheetah at ISO 12800
This gave me a 1/125 of a second exposure, which was as low as I dare go, but I was standing on my seat with my 300mm and 2X extender fitted for a 600mm focal length, but the lens was resting on my hand, and so relatively stable. The cheetah wasn’t moving either, so I got away with this shutter speed. As we can see from this 100% crop though, sure, there’s noise, but it’s totally acceptable in my opinion. What most people instinctively do though in low light, is to be too afraid to increase the ISO and shoot the scene darker, expecting to brighten it up in post.
Cheetah at ISO 12800 100% Crop
The irony here of course is that if you shot this at say ISO 3200, two stops darker, you’d record the image with fewer tonal values per stop of light, making it much noisier, then when you increase the exposure in post, you amplify the noise, giving you a total piece of crap of an image. So, the long and short of it is, if you want to capture the best quality images that you can, shoot to the right, even if you then dial the exposure down in software later.
Last week, a new user on the forums, Chua Kim You, user name redpandafire from Montreal, Canada, revived an old thread from June 2004. I’d posted and article called “Fundamental Advice for Photographer’s Getting Started”. I had to admit, that looking back at this post from over five years ago, there were a lot of things that I would have written differently.
The article itself is a little presumptuous and I would have worded much of it differently now than I did back then, but I as a photographer have also changed a lot over the last five years, and so I decided to sit down and think about how I would write this today, and that is the topic of today’s post and podcast. In fact, this is just part 1. I’m going to release part 2 next week, so stay tuned.
I’m going start afresh today, and just go through what I would probably tell a beginner today. I should say that this is not an article on how to start out as a professional photographer and set up a business etc. It’s more targeted for the total beginner that has just bought a camera, or maybe just made the jump from a compact digital to a digital SLR camera, and wants a kick-start to get them up to speed on the fundamentals. I should also say that it is of course not comprehensive. To cover everything you need to know about photography would require multiple very fat books, not a single Podcast episode. This should be a good primer though, so here with go with my…
Photography Fundamentals for the Beginner (2009) So, you’ve stumbled across photography, and started to make pictures with either a high-end compact digital or a digital single lens reflex camera, or DSLR. Photography is great fun, and to really put yourself in a position to get started quickly, and learn the craft well, I suggest you take the following points into consideration as you experiment with your new camera.
Left Brain/Right Brain
Firstly, realize that although some people can come at photography from one side or the other, in general, to be a good photographer you’ll need to work at being both an artist and a technician, quite often at the same time. People will tell you that it’s not about the gear, and that’s true to an extent, but don’t interpret this to mean that you don’t need to learn how to use your gear or learn some fundamental technical rules and theories. Some of the technical stuff won’t make sense at first, and that’s OK, but the sooner you plant the seeds, the easier it will be to all fall into place later.
Read the Manual
Some people joke about never reading their manual. Some people boast about this, thinking that they are so cool or intelligent that they don’t need to. Both of these activities won’t help you to learn how to use your camera to its fullest potential. No matter how many times I upgrade my camera bodies, the first thing I do is to sit for an evening and read the manual, with my new camera at my side. When upgrading, there are some paragraphs and chapters that are pretty much a straight copy and paste from the previous manual. In this case, skip over it quickly, but don’t ignore it. As this is a guide for beginners though, I assume this is your first camera, so do read the entire manual for your camera, and for any lenses that you have also bought, if you have a DSLR. When you are done reading the manual, you’ll have a good knowledge of what the various settings are for, and how to change them.
Have Fun!
If you are already getting out, experimenting and having fun, that’s great! If not, by all means continue to read/listen to the rest of this, but take your time and don’t get bogged down in details. There is a huge amount of information out there now. Just looking through our Photography Podcasts will certainly help, but the Internet is literally teeming with information on photography these days. So much so, it really is easy to concentrate so much on studying about it all, and trying to learn every detail that you forget to just get out and shoot. Ideally you’ll be able to strike a balance, where you study some of the time, then get out and shoot and experiment to your heart’s content as well.
Exposure Basics There are three elements that will influence your camera’s exposure, and these are the aperture, the shutter speed and the ISO. In the film days ISO was set by the film you bought, and so once you had a roll of film in the camera you were pretty much stuck at that ISO, but now with digital cameras you can change it freely, and so it really can be counted as a per/frame exposure setting.
Aperture – This is the hole inside the lens that controls how much light gets through during the exposure. Apertures are somewhat confusingly rated by small numbers for wide apertures, and large numbers for small apertures. So F2.8 is pretty wide, whereas F32 is pretty small. The aperture size is represented by an f-number and often referred to as an f-stop. Common f-numbers or full f-stops are F1.4, F2, F2.8, F4, F5.6, F8, F11, F16, F22 and F32. With each of the f-number increments, the amount of light that enters the camera to make the image is reduced by half. The weird numbering for f-numbers comes from the fact that they are a ratio of the focal length and the aperture. For example, if you have a 100mm lens with a widest aperture of F2.8, the widest aperture is about 36mm. If we divide 100 by 4, the next full f-stop down, we get a 25mm aperture, which is half the area. Let’s not get too hung up on these calculations for now though. Just note that the larger the number, the smaller the aperture and the less light that gets into the camera.
Shutter Speed – This tells the camera how long you want it to allow light into the camera. The longer the shutter speed, the more light enters the camera and the brighter your resulting photograph will become. Also, as the world around us is moving, the length of your shutter speed can drastically change how your image looks. If you photograph a lake with a fast shutter speed of say 1/250th of a second, you will freeze any movement in the water, and be able to see all of the waves on the surface of the lake pretty much as you do just watching it with the naked eye. If however, you do a very long exposure, like in my example image, number 2320 (above right), all of the movement blurs into a smooth flat surface that we can’t actually see with the naked eye. Shutter speeds are also counted in stops, by halving or doubling the amount of time. One stop faster than 1/250 of a second is 1/500 of a second, and one stop slower is 1/125 of a second and so on.
ISO – The ISO rating is the sensitivity of the film or digital sensor to light. Standard ISO are 100 or 200. It used to be that 100 to 400 ISO was the safe range, before you started to get too much noise or grain in your images, but cameras these days are happily shooting very clean images at much higher ISO, so experiment with your camera to see what you can shoot at, and use the entire range as necessary. As with aperture and shutter speed, ISO is also counted in stops, and doubles and halves as you increase or decrease the ISO.
Note too that most cameras these days allow you to select apertures, shutter speeds and ISO ratings in one third increments, so as you change these values you will have two other numbers in between the full values that we looked at here.
Any of the above values will change the exposure. You can also raise one and lower the others to achieve the same exposure. For example, say we start off with the camera set to ISO 100, with an aperture of F5.6 and the shutter speed set to 1/125 of a second. If you change your aperture from F5.6 to F8, you will reduce the amount of light getting in to your camera and therefore reduce the exposure by one stop. To make up for that with the other settings, you could increase the ISO from 100 to 200, or you could increase the shutter speed from 1/125 of a second to 1/60.
Likewise, if you want to have a faster shutter speed to freeze some action, you could increase it by say two stops from 1/125 to 1/500 of a second, and change the ISO and aperture accordingly. You could change both by one stop, moving the ISO to 200 and the aperture to F4, or you could change just the aperture down to F2.8, assuming that your lens goes that wide. This is a little bit complicated, but hopefully will be making some sense. Don’t worry if it isn’t. We may be just sowing seeds here and it will all fall into place at some point, I assure you.
Depth-of-Field Depth-of-field is the area of the image that is in focus. Let’s look at example image #2289 (below), where we can see the second statue from the right is in sharp focus, but the one to the right in the foreground and the other statues in the background are all blurred. This is because the second statue from the right is inside the depth-of-field, and the others aren’t. This image was shot with a wide aperture of F2.8 and a long focal length of 175mm, using my 70-200mm F2.8 zoom lens.
Huh?
The depth-of-field is directly affected by the aperture, the distance to subject and the focal length of the lens. We discussed the way a smaller aperture lets in less light above, but also, as we make the aperture smaller, we increase the depth-of-field. If we move further away from the object or focus on something deep in the scene, we also increase the depth-of-field, even without changing the aperture.
The closer the subject gets, the shallower the depth-of-field, and this is why close-up, or macro photography requires smaller apertures to achieve enough depth-of-field to get even very small subjects, like the mushroom in image number 2395 in focus (below). In fact, even with an aperture of F11, with a 100mm macro lens, the mushroom which was probably around 1cm in depth is not all in focus. The front and back edges of the head of the mushroom is slightly out of the depth-of-field.
Mushroom and Moss
Also, to illustrate how wide angle lenses have deeper depth-of-field, let’s look at image number 2283 (below) which was shot with an ultra wide angle lens, at 14mm. Here I used F8, a wider aperture than the mushroom shot at F11, and yet everything from the tree that we are looking up into in the close foreground, to the distant trees along the bottom of the frame, is in focus.
Inside the Lacy Leaf Maple
I personally like to shoot with wide apertures and create lots of creamy bokeh, which is the out of focus areas of an image, whenever possible. As a general rule though, when I shoot landscapes, as with most people, I try to get the entire scene in sharp focus, so I work to get a small aperture. It’s a fine balance though, because if you go too small, past F16 for example, the image starts to become less sharp, even though the depth-of-field increases, so you don’t want to just shoot everything at F32.
If I’m doing flower shots, or portrait work, I generally try to get as little of the image in focus as possible. It takes experience to know how much depth-of-field field any focal length, aperture and focus distance combination will give you, but luckily there are tools to play with too. If you have an iPhone, search for one of the great Depth-of-Field tools like DoF Calc. There is also a great tool that works on Windows called Barnack, that you can play with to see how the focal length, distance to subject and aperture create varying depth-of-field.
Get Out of Program Mode
To control the aperture and depth-of-field, as you become more comfortable using your camera, try to move out of the P or Program mode. The Program mode allows for very little control over the Aperture and Shutter Speed. If you don’t understand how to change the camera’s shooting mode, again, look in your manual.
Most of the time, you’ll want to shoot in either Aperture Priority or Shutter Priority modes. Aperture Priority mode allows you to set the camera’s aperture, and the camera will then set the shutter speed accordingly, by looking at the scene and evaluating with the camera’s meter how much light you need to make an optimal exposure. If the scene is very dark, you’ll have a long shutter speed, if it’s very light you’ll have a short shutter speed. You’ll use aperture priority when you want to control the Depth-of-Field (see above).
If you need to tell the camera how fast you want the shutter speed, and don’t care about the depth-of-field, then you could try Shutter Priority instead. You might use this for example when you are shooting sports or racing cars, when you need to stay above a certain shutter speed to ensure that you freeze the action. Many people find though that selecting the aperture in Aperture Priority, and selecting a high enough ISO to maintain a fast shutter speed give the most control. There is also Manual Mode, in which you pretty much take full control, but that’s a little bit more advanced and probably outside of the scope of this post.
Exposure Compensation The light meters and computers in our cameras today are incredibly intelligent. They have scenes in their memory that they compare what you have framed, and try to adjust the exposure they select accordingly. But at the end of the day, they are still machines and they make mistakes. To over-ride this, your camera has a feature called Exposure Compensation. This is usually adjusted by the big dial on the back of your camera; but again, refer to your manual to make sure you know where this is.
You will need to use exposure compensation when the scene you are photographing is extremely light, or extremely dark. For example, to shoot an image like number 2183, which is basically a pale grey tree in a field of snow with a white sky (below), I would have to use around plus one or plus one and a third of a stop exposure compensation. This is because the camera tries to make everything look like an 18% or mid-tone grey. To compensate for this and make the snow look white, I increase the exposure.
Lone Tree on a Hill
If the scene was very dark, like say a brown bear in a dark cave, I would, from a great distance, probably have to decrease the exposure by around one stop, so that the camera didn’t make the scene too bright, which would ruin the mood of the shot. Unfortunately I don’t yet have an example image to show you here.
Check the Histogram
The last thing to note on exposure before we move on is that these days with the digital revolution, we’ve now got the almighty histogram to rely on. So, reading histograms is a little bit complicated and I don’t want to get into too much detail here, but basically a histogram is a graph that you can display on the back of your camera, and I do suggest that you set your camera so that this is viewed when the image that you just shot is displayed in preview mode on the LCD.
Basically the histogram’s graph maps the darkest tones in your image to the left and the lightest tones of your image to the right. The more tones you have on the dark side the higher the graph gets on the left, and the more tones you have on the highlight side, the higher the right side gets and the closer to the right side it gets. Basically what you want to look out for is that the right side of the histogram doesn’t touch the right side or the right shoulder of the histogram, unless you know why it’s there. Say you have the sun in the shot, and you are going to let that overexpose slightly, so you don’t have to make the rest of the shot too dark. Otherwise you basically want to stop the histogram from hitting the right shoulder.
You also want to turn on the flashing highlight warning if your camera supports that, and again, check the manual to see if this is supported and how to turn it on. You’ll have the histogram and the image both displayed on the LCD, and if there are areas that are blown out, they will be flashing. If you don’t care about these areas that we call specular highlights, then don’t worry about it, but if you think that the area that is flashing should be within the dynamic range of the image and not over-exposed, then you’ll want to use the exposure compensation to reduce the exposure slightly until the flashing highlights stop flashing and until the right side of the histogram stops hitting the right shoulder.
See more information on shooting for highlights in my Dynamic Range post.
Use RAW One last thing that I want to mention before we finish for this first part, is that I suggest you get used to shooting in RAW mode very early. If you want, do your practicing and experimenting in JPEG mode, but RAW is actually more forgiving if you get the exposure off a little, and the image quality is better, because the camera doesn’t compress the image, losing some of the detail, especially in heavily textured areas. Using RAW does bring a little overhead in post processing, but tools like Lightroom for Windows and the Mac and Aperture for the Mac only make it so easy to work with RAW files, there really is no excuse, especially as hard disk space is also now so cheap. Do yourself a favour, and just get used to shooting in RAW.
Next week we’ll get into some fundamental composition techniques, and a few other areas, so please do stay tuned if you are finding this useful.
Thanks to Chua for reviving that old thread and prompting today’s and next week’s Podcast. It’s been fun to do this, and hopefully many others will find it useful too.
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