by Martin Bailey | Jun 10, 2008 | Art Talk, Podcast
As I mentioned last week, with the pressures of living in Tokyo and the need to breathe some fresh air got a hold of me and my other half, we took off to the Yachiho Highlands from May 31 for a few days. Today we start to share some of the images I brought back with me in a multipart series. I wasn’t going to spend the whole time photographing, as we took a steady drive over there on the Saturday, because I’d been up until 3AM finishing some work on the Friday night. We also started back at around lunch time on the third day, so the only time for photography was the last few hours of light on the 31st, granted, pretty much the whole day on the 1st of June, and then the morning of the 2nd. It was nice to have a relatively relaxed time though, although as usually I couldn’t resist getting up at the crack of dawn to see how things looked in that first hour or so of light. The main subjects we’ll look at are some wild Rhododendron trees surrounded by White Birch trees, which I love to photograph, and some waterfall shots from the afternoon of the 1st. I also was trying to get a lot of depth-of-field in many of the shots over this trip, which is exactly the opposite to most of my recent work, so I’ll talk about considerations when maximizing depth-of-field too.
As is so often the case, with my busy day job, and then fitting in my photography, which is definitely like having a second full time job for me, I didn’t actually book the hotel for the Saturday and Sunday nights until Friday night. I didn’t even book the days off from my day job until the Friday evening before I left the office at around 7PM, then I had to get two invoices off to a client for my Photography work, so I was really leaving all of this until the last minute. Having booked the hotel the invoices couldn’t wait either, so as I just mentioned in the intro, I was up until around 3:30AM on the Friday finishing up everything that had to be done. The idea was to have a relaxing weekend, though get lots of photography in too, so I didn’t push it by trying to get up in just a few hours to drive for three to four hours to the Nagano Prefecture, which is where we were heading. I was still pretty tired, having gone to be so late, but after having almost six hours of sleep, I got up at 9:30, got breakfast and got my gear together. We jumped into the car at just after noon and had a steady ride out of Tokyo and over to Nagano. Having stopped for a bight to eat on the way, we arrived in the area at around 5PM and started to scout out some photo opportunities.
I actually came here in mid-May, 2007, having seen a photograph of a wild Rhododendron tree in the White Birch trees that this area, Yachihokougen, is pretty famous for. The weather forecast had been rain for the Saturday, and then clear for the Sunday, which was perfect, as I wanted to photograph the Rhododendron trees in the mist if possible. When I came last year though, I couldn’t find any of the trees flowering, and when I asked a local, it seemed that the late snows had held the flowers back last year. This time, I was heading out here two weeks later than last year, because again, I’d heard there’d been some late snow, so I was hoping to found some of the trees flowering. The other problem was that I didn’t actually know which parts of the White Birch woods the Rhododendron trees were in, so it took a little bit of driving around, and even then, I couldn’t see anything obvious. The roads were empty though, so I figured leaving my car parked and having a walk into the woods wouldn’t hurt, and the White Birch has to be one of my favorite trees anyway, and because it was pretty misty with the low cloud, I figured that if nothing else, I’d be able to shoot some nice misty birch trees.
The funny thing was though, within literally 30 seconds of walking up the hill into the woods, I started to see the odd Rhododendron tree flowering in the mist, so I was starting to feel pretty happy about my choice of place to stop. Let’s take a look at the first image for today, which is number 1801. Here we can see the tree, with beautiful deep orange, almost red flowers, amongst almost all white birch trees. The mist was not that thick, so isn’t really registering very well here, but hopefully you’ll get a sense of the moment. It was raining pretty heavily too. At this point, my significant other was still enjoying the fresh mountain air, and happily holding a large umbrella over us both and my camera gear, set up on a tripod. We’ll look at maybe up to 20 images from this and the next episode, but I wanted to note that all but one of them were taken using a tripod. I’m a big believer in using a tripod to make the whole process of photography very well thought out and deliberate. Some of the images we’ll look at would have been possible without a tripod, but I am a proponent of using them whenever time allows, not just when the shutter speed or circumstances demand it. When I shot this particular photograph, I’d already been further up the slight incline, and shot the tree from a very low perspective, which is image number 1800. I won’t include that image today, for the sake of time, but I’ll put a link to all the images from this long weekend in the show-notes.
Wild Azalea in White Birch
What I wanted to mention though is something that I’ve mentioned a number of times before, which is to always be aware of what is behind you. I spent maybe thirty minutes shooting this tree and the surrounding birch trees in various ways, and had started back down the hill to where the car was. Whenever I’m walking away from a scene though, to the great disappointment of my other half, I continue to look back, to make sure that I’m not missing something that would make a nice shot. I feel that when you are approaching a scene, you can be more interested in getting in and working the location, and are all excited about seeing what there is to offer, but there is no intimacy between you and the subject matter yet. You’re still exploring. Once that exploration is done though, and you decide what angles to shoot it from, what lenses and apertures and shutter speeds to use, you start to become more comfortable with the subject. Then when you feel you’ve exhausted all the possibilities, you pull the cord and start to walk away. The fact is though you usually haven’t really exhausted all the possibilities. You’ve probably really only scratched the surface, so I always keep an eye on a scene as I move away from it, in the hope that a face that I was not open to earlier presents itself to me now that I am more familiar with the subject or location.
Although I’d been shooting nice and wide with my 16-35mm F2.8 lens earlier, I used the 70-200mm F2.8 lens for this shot. I had moved away from the scene, but I was also moving down the hill, so we can see that my eye-level is almost ground level here, as we look across the forest floor. The focal length was 100mm so the telephoto has compacted the perspective a little, allowing the trees to almost be on top of each other, but still have a little bit of distance. I have placed the tree just off center towards the bottom right third, and ensured that the threes to the right and left are cut off in a non-distracting way. I used an aperture of F11 to ensure the whole scene was in focus, and that gave me a shutter speed of 6 seconds at ISO 100, so you can probably appreciate how dark it actually was at the end of this rainy afternoon in the mountains.
Shortly after shooting in this patch of trees, as the light was fading pretty fast now, we decided to head to the hotel for our first evening. As we rounded a corner on the mountain road heading down into the valley, both me and my other half gasped as we saw that the valley was totally enshrouded in cloud. We thought for a split second that we might have even been gazing at a huge lake, but there shouldn’t be a lake of this size in this area, unless my map reading skills had been totally off. There was a lake down there, but it should not have been that big. A few moments after starting to view the scene it became obvious that this was cloud, but still, it was sitting so perfectly in the valley, surrounded by the mountain on which we were standing and the mountains on the other side. I guess that’s what makes it a valley, right? Right there though, there was a lay by, so we pulled up and jumped out of the car. The light was fading fast, but it was a beautiful moment that I did not want to miss. We’ll look at two shots from here, and the first one is number 1802.
Yachiho Evening Sky #1
It isn’t as easy to see the clouds in the valley here, because I’ve shot this at 16mm, with my 16-35mm F2.8 lens. This first exposure lasted for 20 seconds at F11, still at ISO 100, so again, you will be able to appreciate how fast the light was dropping now. The long exposure has made the clouds close to me blur, a little like a lensbaby image, but this was not only expected, but an effect that I wanted. Of course, the clouds further away aren’t moving as much in relation to my position, so they aren’t blurred. They are obviously moving at the same speed, but they are coming towards me, as opposed to moving over me. I converted to black and white in Lightroom, and dragged the blacks down a little to emphasize the heavy sky and also bring out the black of the mountains on the other side of the valley. They were a little greyer in the original. Again, I decreased the saturation of the all the colors to zero, then adjusted the balance between each color channel with the Luminosity. I think I heard Derrick Story talk about this tip that he’d picked up from someone else on his Podcast “The Digital Story”. If you don’t listen to that Podcast actually you should. Some of it can be a little basic, but there’re often a few gems to pick up for just about any level of photographer and Derrick has a very entertaining way of putting his message across. Anyway, converting to black and white in this way prevents the shadows from going all grainy and muddy, so try it yourself next time you convert something to black and white.
I said that I would also talk about getting lots of Depth-of-Field in this Episode too, which I’ll get into more shortly. For now, I wanted to say that if I was not too worried about calculating the hyper-focal distance for my shots over these few days, because I wasn’t really looking at getting a sweeping landscape in with the whole scene in focus from front to back, in the usual sense. If you want to learn what hyper-focal distance is and how to use it to achieve what we call pan-focus, then you might want to listen to episode 65 that I did, called Understanding Hyper-focal Distance. You might be wondering why I didn’t want to use it for this shot, but just look at how far away from me that line of trees is and think about the focal length I’m shooting at. At 16mm, basically the lens goes hyper-focal at 3.6m or 12.5ft, even when wide open at F2.8, so if I focused at 3.6m, everything from 2m to infinity will be in focus. Those trees were a good 50 meters in front of me, and I knew that everything this side of the trees was going to be black anyway, so I could have shot wide open and focused on the trees and I would have been fine. Remember though that I wanted a slow shutter speed to emphasis that heavy sky, so I closed the aperture down to F11, which gave me a nice long 20 second shutter speed. At F11 by the way, the hyper-focal distance is 1m, but we already know that that is irrelevant for this particular shot.
Let’s take a look at another image which is literally the next exposure I made, which is image number 1803. Here what I’ve done is zoomed in from 16mm to 35mm literally going from one extreme of the lenses focal range to the other. I changed the exposure time from 20 to 30 seconds as the light died, and wanted really here to give us a feel for the clouds, that I could see rolling over the edge of the smaller mountains in the distance to the left. You also get a better feel for the sea of clouds in the valley here, as well as the distant mountains and that wonderful dramatic sky. For the black and white conversion, I simply synced the settings from the previous conversion. No need to reinvent the wheel, as I’d just spent some time figuring out the best place for the Luminance sliders for the previous image. Here we also see more detail in the foreground trees, which I’ve focused on, but again, the entire scene is sharp, because the hyper-focal distance even at 35mm is 4.6m, or 15ft. I’d have still been OK at F2.8 but that would start to worry me a little. I wasn’t using my DOF utility on my cell phone by the way, and I’m using Barnack to lookup the exact numbers for the sake of the Podcast. But the more you use hyper-focal distance the more you get a feel for where you need to be with your lenses, so it isn’t always necessary. Especially here, I just knew that I’d be way OK if I focused on those trees and let the physics of the lens do the rest.
Yachiho Evening Sky #2
This particular time was actually incredibly special. Once I’d gotten the camera set up, and was making a few exposures, and just standing there listening to the sounds of the forest. The birds were just about all asleep now, though there was still a little bit of chirping going on as they settled in to roost, but every so often we could hear the cries of what sounded like the dominant male in a pack of macaque monkeys, not far from where we were. As you look at this image, the area to the right, is actually a very deeply wooded area of deciduous trees, and seems to be home to a fair number of macaques. We’d also startled a pair of deer moments earlier with my headlights, and was feeling pretty close to nature, even though we were little a few paces from the car at this point. Without getting all Mills and Boon on you, I had put my arm out and pulled my significant other over, and with my arm around her shoulder just stared out across this magnificent vista while listening to the cries of the macaque and birds settling down for the night. These literally final moments of the day were truly magical, almost spiritual. The hair on the back of my head stood up as I waited for my exposure to end. It was this, the fresh air, the beauty of the land and nature, and the sounds of the wilderness that had brought us some three hours northwest of Tokyo on this murky yet beautiful Saturday afternoon.
Show Notes
Check out TinEye here: http://tineye.com/
Here’s a link to Mikkel Stegmann’s Barnack utility that I reference so much for depth-of-field and hyperfocal distances, and mentioned in the Podcast: http://www.stegmann.dk/mikkel/barnack/
The music in this episode is from the PodShow Podsafe Music Network at http://music.podshow.com/
Audio
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Download this Podcast in MP3 format (Audio Only).
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by Martin Bailey | Apr 12, 2008 | Art Talk, Podcast, Travelogue
Last week I was in India for a brief business trip with my day job, and had a wonderful experience in the market that I’d visited in September of 2007, when I shot some great portrait shots that I shared with you in Episodes 105 and 106. This is the first of a two part series in which I’ll explain what happened this time, and share some thirteen or so portraits of the wonderful people I met at the market this time.
You might remember that back in Episode 105 and 106 I discussed a series of portrait shots that I made during a 30 minute work through the Madivala vegetable market in Bangalore, India, back in September 2007. I had been there on business, for basically a flying trip, and really the only photography I did was from the plane on the way out and back, and these thirty minutes in the market. I’d devised a strategy to get people used to me very quickly. Basically, like many people, I experience a little anxiety when walking up to people and asking if I can take their photograph. I had also decided a while ago that I would no longer just shoot people from the car while on these business trips, as it was at best too impersonal, and possibly, no, probably just downright insulting to have some outsider whizzing past in a car shooting out of the window like some sniper.
Anyway, my strategy last year was to walk through the market with my camera around my neck, but not take any photos at all on my first walk through. I simply smiled and said hello to many of the people I saw as I walked. Then when I got to the end of the market, I turned, and walked back through. Then, the people that had seen me walk through the market minutes earlier, with their curiosity somewhat aroused, started to call out to me, and ask where I came from and what I was doing there. With the camera around my neck from the start it was easy now to ask if it was OK to take their photo, and as I shot some people, a buzz started in nearby stalls, and as I moved along, many others actually started asking me to take their photos and it was also much easier for me to ask those that didn’t ask me. It was a wonderful experience, and I felt strongly that I wanted to do something in return for their warmth and kindness. I actually mentioned at the end of the two podcasts on this last year that I wanted to take back some prints for the people that had allowed me to shoot them.
Well, at about 1AM on Sunday the 13th of April, just six hours before I was due to leave for the airport to go back to India, when I finally finished recording Episode 132 of this Podcast and was almost packed, I selected 10 photos of the people at the market, and loaded my printer with 5×8” Epson paper, and started to output the prints. I have to admit, I’d been pretty busy with various things and though for a moment that I might give up on this. I was thinking that the people may not even be there, and I needed some sleep. But, if they were there, I would never have been able to forgive myself for my laziness, so I went ahead and made the prints.
Well, at around 9:30AM on the morning of the 15th, I drove through the market on my way to a business meeting. Then, I saw one of the people that I’d photographed at a fruit stall. Then as we went further along, I saw the fish stall where I’d photographed the family. At this point I could find anyone else, but I was so happy that it seemed that at least some of the people were still there. I didn’t stop at this point, as we had to be somewhere for a meeting. I did tell the other’s with me though that if possible I’d like to stop for 30 minutes on the way back later in the day, to give them their photos. I showed them the photos and they thought it was an excellent idea. So the stage was set.
Well, at around 3:30, we arrived back at the market. I have to admit, I was a little apprehensive, as I didn’t know how they’d react, but we parked the car, and headed towards the stall where I’d recognized the first man. I approached the man from the fruit stall, and said hello, and asked if he remembered me. He didn’t seem to understand, but he did seem to possibly recognize me, and as I spoke, I handed him his photograph. He was laughing, and looking back at his wife, they seemed as though they recalled and were talking about my previous visit. There smiling faces were all that I wanted, and I’d seen them, so I was now happy. I asked if the people in the photos that I recalled taking near their stall were still around, and they were, in the back of the stall next to theirs. I started to hand out their photos too, and again was rewarded with laughter and smiles as everyone viewed and passed the photos around.
We walked further along, and it just kept getting better, I saw more people, and handed over the photos, and when we got to the fish stall, some of the people that I’d shot before were there, though some weren’t. There were many more people though too. As I handed the photos over, they started asking me to take their photos again, and the new people all joined in. Let’s look at the first shot, which is shot number 1740. We started with this big group photo, which they initiated. I had only taken my 85mm F1.2 lens, so I had to step back quite a way to get everyone in, but I guess this will have helped to get a nice perspective. I was not so happy that the wooden pillar holding up the stall was in the right side of the image, but I didn’t particularly want to start choreographing everyone either, so I went with the flow. I really like this shot as everyone is smiling, so it really relays the happiness and friendliness of the moment. Although it was a bright sunny day, I’d learned when I came here before that most of the time the people were under the shadow of their stall canopies, so I’d set my ISO to 200 from the start, and I selected an aperture of F4 for this shot, which required a shutter speed of 1/320th of a second for good exposure.
The Fish Mongers
Fish Mongers with Catfish
After this, they all started asking for individual or group shots. I have to admit, that although I’d been hoping to shoot a few more photos, hence my camera around my neck with the 85mm fitted, I was in handing-over-photo mode, and it all started to take off into a photo shoot, but who am I to stop the flow, right? It was great! I was enjoying the experience incredibly. In the next shot, image number 1741, we can see who I think is the owner of the stall, with a prize catch catfish. He’d been trying to get a shot alone, and kept elbowing the others out of the scene, but this young guy in the burgundy shirt came in behind, so I got the shot. I quite like this actually, with both of the gentlemen’s heads tilted at a similar angle. This was also shot at F4, but I lowered the shutter speed to 1/200th of a second as there were fewer highlights to protect from blowing out.
Next, was a somewhat frustrating result, as the two guys we can see in image number 1742, had posed with a couple of really mean looking smiles. In this shot, only the guy to the left of the frame has this look, but in the first few shots they’d both had that tough, pensive stare. This of course was a front, just a pose, and they’d actually cracked up laughing at some point, which I also got, but unfortunately the focus on the first few frames was a little off. Well, what had happened was I didn’t have them paralleled, and this meant that with the shallow depth of field from the F4 aperture, that one of them was outside of my depth-of-field. I thought this might be the case, and so got myself parallel to them from around this shot. The guy in the background detracts from the main subjects a little, but he was determined to be in the shot. As I moved to be more parallel to these guys, the guy in the background also shuftied along the stall a little to stay in frame. He did this in pretty much all the shots here, but again, I was not going to start and choreograph these guys.
Tough Fishmongers
In shot number 1743, we can see three wonderful smiles. Actually four if we count the stall owner in the background again, but these three young boys, again with their prize catfish all gave me a wonderful smile each. They’d actually gotten a little bit serious for a moment, so I dropped the camera and gave them a big smile myself, which is what they were reacting to here. Again, I have a vexing memory from this point, as they all started laughing at each other laughing, with the boy to the right pointing with his arm stretched out at the boy on the left, but as they did so, they all rocked backwards, and the focus ended up perfectly on the face of the catfish. I was back up to a shutter speed of 1/320th of a second here again, and the last shot for that matter, though still with an aperture of F4. As when I was here before, after each shot, I showed them the photos on the LCD, then shook each of their hands and thanked them. This time many of them started to ask for their photos, which is fine of course. It’s the least I can do, so I promised to take them back on my next trip.
Three Wonderful Smiles
As we walked further along, I spotted the gentlemen with the red and white checked head-dress that I’d shot such a wonderful photograph of on my previous visit. This is the one that is almost like something off of a National Geographic Magazine cover. He didn’t recognize me at first, which is hardly surprising, but I walked over and showed him the photograph, saying “Do you know this gentleman”? Well, I wish someone else had gotten a photo of this exchange, because his face was a picture. He literally lit up. He was so excited, and in turn of course, so was I. Again, we shook hands, and I thanked him again for his picture. Now three friends came by and they all looked at the photo, and we all laughed together. Then they requested another photo, so I had them all sit down and took a few shots. The result is image number 1746. I was actually regretting to an extent that I only had my 85mm with me. I was not expecting so many group shots, and I had to stand way back to fit all of them in. I wasn’t too worried at the time though. I was having such a great time, and I believe they were too, so the exchange was more important to me than the resulting photos, in this case at least.
Merchant Revisited
I had to do a little bit of Photoshop work on this shot, as there was actually a fly right over the left side of the man with the blue shirt in the first of the two frames I shot. The first was the better shot though, as I’d cut off even more of the hands of these men in the second shot, so I took the left eye, cheek and ear of the man in the blue shirt from the second shot and grafted it over the first. Still shooting at F4, I had selected a shutter speed of 1/250th of a second. The guy on the left of the group as we view the shot had a white shirt on, which we can see has severely blown out under the direct sun, but I wasn’t too worried about this. We can see why it’s so blown out. That aside, it really was a great experience to meet the gentleman with the red and white checked head-dress again. I have stared at his photo so many times over this last 7 or 8 months, and to see him again in the flesh, especially as excited as he was, though you can’t see it in this shot, really was a treat.
So, let’s leave it there for today, and pick up the trail again in the next episode. I will try to get that out this week to make up for some missed episodes recently during a family visit. Remember that our current assignment is on Abstract and you have until Sunday the 18th of May to get your entry uploaded to the mbpgalleries assignment album, which brings me nicely on to the subject of our little hackerification last week. While I was in India, I became aware of some mbpgalleries.com Web site issues, that after a quick look, I feared were the work of a hacker. I tried to work on this while on the road, but really couldn’t make the time to look at it properly, and as I was there on business in my day job, not for photography, I actually didn’t have any of the files necessary to really fix anything anyway. Still, when I got back home on Friday evening, I soon confirmed that we had indeed been subject to the work of a certain species of pond life that prays on people having fun, for no profit. It really saddens me to think that there are people like this in the world, but I guess there is nothing we can do about it. I know the name of the Web site that this hacker was trying to redirect us to, and also trying to distribute their Trojan horse style virus from, but the Internet is currently designed so that people can hide behind privacy measures at their service providers, and it really isn’t easy to stop them. Anyway, if you had problems with the mbpgalleries web site last week, I apologise for not being able to fix the issues more quickly. I actually upgraded the album software on Saturday to close the security hole that had apparently let them in, so we should be OK now. Sorry for the inconvenience anyway.
So, let’s call it a day for today, and I’ll be back later with part two of my trip to the Madivala Market. For now though, you just have a great week, whatever you do. Bye bye.
Show Notes
The music in this episode is from the PodShow Podsafe Music Network at http://music.podshow.com/
Audio
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by Martin Bailey | Apr 12, 2008 | Fundamentals, Podcast, Tutorial
I’ve rarely seen an easy to understand explanation of how the aperture and distance to the subject affect the depth-of-field in our images. When I started to think about how I would explain this, I started to understand why, because it wasn’t easy to do this in a simple way, and I still am not sure if I’ve succeeded. I’m sure you’ll let me know. Anyway, I’ve created six diagrams to help me explain this. I’ve not attempted to draw scientifically accurate diagrams, rather just created them in Microsoft Word to help me explain more easily with words. So let’s jump right into it and attack what should be a very simple subject, though it never seems to be.
I’ve included the diagrams below, but I also published a rough PDF of the diagrams, as it might be easier to compare the diagrams by just flicking through the pages of the PDF. If you move page by page rather than scrolling, you see the next chart an instant after the first, so it’s very easy to see the changes.
Anyway, let’s go ahead and look at Diagram #1. You can see that I’ve basically drawn a mock-up of a lens, with a few lens elements, and an aperture ring. The dotted line running through the center of the lens is the lens axis, and the thin blue lines that make their way through the lens from the film plane to the point we are focusing on in basically representing the light coming into the camera. I’ve used the actual metrics associated with a 50mm lens, and for now, we are focusing at 2m, or around 6.6ft, and I’ve made the aperture f/2.8, which I’m imagining is pretty much wide open for this 50mm lens.
(Note: click on the images to enlarge, and use your keyboard arrow keys or click either side of the image to move between them.)
DOF Diagram #1
What I want you to take note of right now is the X that the blue lines make as it intersects at the point at which we have focused the lens, two meters in front of the lens. Either side of the X I have drawn a circle. You can think of this circle as the circle of confusion if that helps. If you don’t understand what the circle of confusion is, take a listen to Episode #65 when I discussed Hyperfocal Distance. It’s not important that you fully understand what the circle of confusion is right now though. Just think of it like this. As we move away from the point that we are focused on, the elements in the frame start to become less sharp.
The point that we are focused on is the sharpest, but even before we leave what we call the depth-of-field, things start to get closer to being what we’d consider out of focus. These circles represent the nearest and furthest points at which the subject or elements around it will still be perceived by us as being in focus. In the diagrams, I’ve called this the far limit and the near limit of acceptable sharpness.
So, the light travels from the scene, into the camera through the lens, and the elements within the lens move around when we focus to make sure that the image comes into focus at the focal point on the film or sensor that we can see as a dotted line on the bottom right of the diagram. Although some of the lens elements do move around, in reality, it’s not important to understand this concept, so I’ve not changed them in the diagrams.
Before we move on to the next diagram, let’s note the size of the depth-of-field when focusing at 2 m with a 50 mm lens. The depth of field is 27 cm or just over 10 inches. Also visually note the angle of the intersecting lines that make the X at the point at which we are focusing. Let’s now take a look at Diagram #2.
DOF Diagram #2
The only difference between diagram one and two, is I’ve stopped the aperture down by two stops from f/2.8 to f/5.6. You’ll see that the angle of the intersecting lines making the X at the point we are focusing on, still, 2 meters, is now much closer. So that we are all thinking the same way, imagine you are looking at the X from the front of the lens, so the lines just got closer.
Now, the circles that represent the near and far limits of acceptable sharpness have to be moved further out so that they fit between the lines. With just two stops smaller aperture, the depth-of-field widens from 27 cm to 54 cm, almost double. This is because we are focusing at 2 m, just over six feet from the film plane.
Let’s look at one more diagram while focusing at 2m. In Diagram #3 we will close the aperture by a further two stops to F11. Look how close the two intersecting lines of the X at the point we are focused on are now. We can also see that the depth-of-field has increased greatly. Now to get the two circles of acceptable sharpness between the lines, we have to move them much further apart.
The depth-of-field increases to 1.14 m, or 3.74 ft. Compared to the 27 cm we had with an aperture of f/2.8 focused at 2 m, we now have over four times more depth of field. So, we have seen here that even at the same distance to subject, we can greatly increase our depth-of-field, just by making the aperture smaller.
DOF Diagram #3
In addition to the aperture though, distance to subject, even at the same aperture has a huge effect on the depth-of-field. Obviously, because the lines of the X that we’ve been looking at continue to move apart, and the further away from the depth-of-field, or the area of acceptable sharpness they get, the more blurred the foreground and background gets.
This is why the acuter the angle of the X the more quickly we start to see lots of out of focus areas or bokeh. In Diagram #4 I’ve scaled the diagram down to around 1/2 size so that we can get it on the page, but if you look at the numbers and the size of the camera etc. I don’t think this will be too confusing.
DOF Diagram #4
Anyway, what we’ve done now is kept the aperture at f/5.6, which is of course relatively wide, but now we’ve focused on something 5 m or 16.4 ft away. Look how much closer the lines of the intersecting X are now compared to diagram #2 when we were focusing at just 2m. The depth-of-field has also increased from 54 cm or 1.7 ft to a whopping 3.8 m or 12.5 ft. This is seven times more depth-of-field, just by focusing at 5 m instead of 2 m. So now we can see how focusing further away increases the depth-of-field even with the same aperture.
Just to reinforce this, let’s now look at Diagram #5, and focus much closer to the lens. Let’s imagine we focus at 50 cm or 1.65 ft in front of the film plane. All focusing distances are measured from the film plane by the way, so it’s not a problem thinking about the distance from the film plane instead of from the front element of your lens. Still with an aperture of f/5.6, see how wide the lines of the intersecting X are now, and how close the circles of near and far acceptable sharpness now are. We have a depth-of-field of just 3 cm or just over an inch.
DOF Diagram #5
If we open the aperture up to f/2.8, as in Diagram #6, we can see that the lines of the X get even wider apart, and the depth-of-field is reduced to 2 cm or just over half an inch. If we compare this to Diagram #1, when we focused at 2m with the same f/2.8, the depth-of-field has reduced from 27 cm to just 2 cm, by changing the focusing distance from 2 m to 50 cm, or one-quarter of the distance.
DOF Diagram #6
I think we’ve probably had enough of diagrams now, so I didn’t make any more, but I’m sure this will help you to appreciate why the depth-of-field gets so much shallower when doing very close macro work. Sometimes we’re focusing on things just in front of the lens, literally, if working at magnifications larger than life size. Say I’m using a short macro lens, and focusing on something very close to the lens, at about 20 cm from the film plane, my depth-of-field is reduced to 2 mm because the lines of the X intersect at such a wide angle. When you do go larger than life size, it is not uncommon to have a depth-of-field of less than a millimeter, and have to stop down to f/11 or f/16 to get more than a millimeter.
The other thing to bear in mind is that focal length has an influence of depth-of-field as well. The reason for this is because if we still focus at 2 m, say with a 100 mm lens, instead of a 50 mm lens, the subject is magnified to twice the size. This, in turn, means that we are magnifying the circles of acceptable sharpness, so they go out of focus twice as much. To counter this we have to half the size of the circle for it to still be acceptably sharp, and that means that the circles move closer to the intersection of the X, and the depth-of-field decreases. Basically the longer the focal length of our length, the smaller the circles of acceptable sharpness get.
Anyway, I hope this has helped if you didn’t really understand why aperture and subject distance affected the depth-of-field the way it does. If you are still confused, how about grabbing a small object, and a tape measure, and setting up your camera on a tripod and put the object 2 m away from the camera, and take three photos. One with your lens wide open, then stop down by 2 stops, so if you start at f/2.8 you’ll go to f/5.6 and a third having stopped down by 2 more stops, so f/11. If your lenses widest aperture is f/4, try f/4, f/8, and f/16. Then move the object you shot to 50 cm, or as close as you can focus on it, if your lens doesn’t focus as close as this, and shoot three more shots with the same three apertures. Then move the object out to 5 m, and repeat the three shots. Then take a look at your images on your computer, and you will be able to see the difference very clearly.
Another very simple trick you can try is to hold out your finger, at arm’s length, and focus on it. Notice how blurred the background is using your peripheral vision. Don’t actually focus on the background, just see it while focusing on your finger. Then move your finger towards your eyes, while continuing to focus on it, kind of like in AI Servo or continuous focusing mode. As your finger gets closer, you’ll notice that your surroundings go out of focus even more. Move the finger back out, and the surrounds become more focused. You can do this with both eyes open or just one and see the effect, but bear in mind that your camera only has one lens, so closing one eye should help you to see very much as your eye does.
Podcast show-notes:
Here is the PDF file that contains the six diagrams I use to explain this topic.
Here’s a link to Mikkel Stegmann’s Barnack utility that I reference so much, and mentioned in the Podcast:
http://www.stegmann.dk/mikkel/barnack/
Note, since releasing this Podcast, I also released an iPhone app with a very nice Depth-of-field calculator built in – check it out here: https://martinbaileyphotography.com/mbp-podcast-companion-app/
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