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Photographer’s Friend is the only app in the App Store that contains a Depth of Field Calculator and a Neutral Density Filter Calculator, and an Exposure Shift Calculator!
For full change history including all fixed issues, see the Support Page.
The Depth of Field Calculator [DoF Calc] is intuitive and easy to use, but provides a level of detail to satisfy even the most discerning photographer! Just select your camera sensor type (35mm full-frame, 1.3X 1.5X or 1.6X crop factor, 1-inch, micro 4/3, or one of the medium or large format sizes) then choose your aperture, focal length and focus distance (the approximate distance to your main subject).
The calculator then instantly displays your depth of field including the near limit, far limit, and hyperfocal distance. If you tap the Hyperfocal Distance label the focus distance dial is automatically set to the hyperfocal distance and all displayed information is updated. Tap again and your initially selected focus distance is restored.
Tap the [Focus ft/m] button to toggle between feet and meters. To make this interaction easy to remember, the labels that have a function are blue.
Traditionally Depth of Field is calculated assuming sharpness determined in an 8 x 10-inch print viewed at arm’s length, but this can lead to slightly soft images when evaluated at 100% on a computer screen. Enter Pixel Peeper mode! The first difference is that the calculated depth of field is somewhat shallower in Pixel Peeper mode, to ensure that your image is sharp when inspected while zoomed in on a computer. This means that you would have to use a smaller aperture to gain adequate Depth of Field.
When enabled we calculate and display your Pixel Pitch, Airy Disk, and Circle of Confusion size, and calculate Depth of Field, all from your selected sensor size and megapixels.
There is also an option to display diffraction warning color coding for the Airy Disk display and Aperture dial. Green means no problems, amber indicates there’s a risk of seeing effects of diffraction, and red lets you know when your image is most likely diffraction limited.
Note that whether or not you actually see the effects of Diffraction in your photograph depends on your camera and lens, and your own perception of sharpness. The Diffraction Warnings are intended as a guide, to show you when the risk is there, but there is no guarantee that you will actually see anything in your image. In our tests with a Canon EOS 5Ds R lens, we found that Diffraction doesn’t become noticeable in photographs until f/22. We strongly urge you to test your own lenses, and if necessary, you can calibrate the warnings by using a different megapixel count or Custom CoC so that the red warning kicks-in in line with your findings. Information on how we tested for Diffraction can be found in this post.
You can also enter a custom Circle of Confusion size as a basis for Depth of Field calculation if you prefer.
Photographer’s Friend comes with both a Light and Dark Appearance, and to switch between the two, you just have to shake your device. This is useful, for example, if you generally like the Light mode, but occasionally use Photographer’s Friend at night. Just shake your device to switch to the Dark Mode, which from version 3.2 changes every screen in the app to a sleek Dark theme, which not only protects your night vision, it looks really cool too!
Note that you’ll need iOS version 13 or higher to enable the Dark mode. Also, there is a third mode that simply adjusts the appearance to use your device default settings. If you have your device set to Light Mode, Photographer’s Friend will use Light Mode. If you switch to Dark Mode, Photographer’s Friend follows suit.
We didn’t have to go this far but thought it was fun to provide apertures down to f/0.7 because there are actual lenses that go that wide, although very rare. You can also increase the focal length and/or decrease focus distance to the point that your depth of field is as shallow as 0.1mm, and then we switch to µm (micrometers or microns) and continue to calculate down to less than 0.001 µm. That’s one-millionth (0.000001) of a millimeter or the length of just 10 atoms! Talk about razor-thin depth of field! Crazy, but fun to play with, and you never know, you might need this one day.
When you first install Photographer’s Friend, a Quick Tips tutorial will display multiple passages of textual help over the four dials in the DoF Calculator and Exposure Shift Calculator to get you started. To view these tips again, just tap the Quick Taps button on each respective screen.
The neutral density filter calculator takes any shutter speed that you can set on your camera and calculates your new shutter speed after applying neutral density filters to your lens. The filters are labeled by the multiplication factor (ND2, ND4, etc.) and also have the f-stop and optical density values for each filter, so there is no confusion as to which filters to select.
A timer is available for shutter speeds of 5 seconds or more, so if you don’t have a timer switch or built-in timer in your camera, we’ll time your exposure for you. If you get a phone call or need to use another app during a long count-down, just background the app, and it will update when you open it again.
When you first set a timer, we’ll ask for permission for Photographer’s Friend to use Notification Center on your iOS device. We only use this for the timer, but when enabled, we’ll display an alert when the timer finishes, even if you close the app or reboot your device during the count-down.
Although it’s unlikely that you’ll ever need this in
To hide filters that you don’t use just slide them to the left. Once filters are hidden, the button below the Shutter Speed dial displays how many filters are hidden. Tap this button to display the hidden filters with a dark background, and slide them to left again to unhide them if
Photographer’s Friend runs great on iPhones and iPads of all sizes. It also supports split-view on iPads that support it, so you can shrink the app down to various sizes and view other apps at the same time!
When changing the exposure on your camera, it’s not always obvious which settings to change to counter adjustments you make. When you adjust your aperture from f/5.6 to f/11, does your shutter speed need to go up, or down, and by how much? How does it affect your ISO?
Enter your current camera settings with the Aperture, Shutter Speed and ISO dials, and watch Photographer’s Friend calculate how changes to one dial affect the others. You can lock any of the three dials to calculate just the other free dial automatically, or turn on Exposure Value Lock to have Photographer’s Friend calculator all settings for you!
To store your initial settings as a reference, slide the blue central band to the left. To update the settings, slide left again, or slide right to close the blue band.
The Exposure Value display and lock is invaluable when looking for appropriate settings from a light meter EV readout. We’ve also added a button to send your aperture to the Depth of Field Calculator and another to forward your shutter speed to the Neutral Density Filter Calculator.
We’ve included a huge range of apertures and ISOs that are not available on many cameras. These are great for educational purposes, but in practical use, you will probably not need them, so we’ve included a settings screen that appears when you tap the cogwheel in the bottom left corner of the Exposure Calculator, and in the settings, you can set the top and bottom limits of each of the three dials to bring the ranges in line with your camera or your own acceptable setting ranges.
On the Links tab, we’ve included a scrolling list linking to in-depth articles on Hyperfocal Distance, Understanding Neutral Density Filters, Understanding Exposure Value, and Circle of Confusion, as well as links to our Podcast and Blog, which has been released weekly since 2005! There are links to email us directly or use our web contact form to ask general photography questions or send questions or suggestions for the app. We think we have all bases covered, but for example, if you own a Neutral Density filter that is not listed, let us know and we’ll consider adding them in a future update.
There are two multi-page help sections with detailed information to help you understand the Depth of Field calculator, the Neutral Density calculator, and the Exposure Shift Calculator. Just swipe through the pages and tap Done to return to the Help tab. Along with the linked articles, you’ll fully understand these topics in no time.
There’s now a link to our Photographer’s Friend Video Tutorials page, with a video to explain how each calculator works.
Whether you are just getting started or a seasoned professional, or maybe an educator, we think you’ll find these three calculators in one app invaluable.
Pick up your copy of the Photographer’s Friend from the App Store today!
Note that it is no longer possible to buy iOS apps on a PC. Please click through to the App Store on an iOS device and opt to open the link in the App Store app to buy Photographer’s Friend.
Alternatively, if you have a QR code reader on your device, you can scan this code! If you have upgraded to iOS 12, there is now a QR code reader in
For those of you that have kindly bought version 1 or 2, we figured out a way to offer you upgrade pricing, by creating an App Store Bundle. The pricing varies by country and also when local taxes are added, but to illustrate the pricing model, I’ll use the US App Store base pricing.
There were various prices for versions 1 and 2 over the years, ranging from the introductory price of $2.99 which then changed to the regular price of $3.99. If you paid $2.99 for your previous version, you’ll be able to upgrade for $4, a saving of 20%. If you paid $3.99 for a previous version, you will be able to upgrade for $3, which is a saving of 40% off the full price.
Once you have completed your bundle, you can delete version 2 from your device, as all of the functionality of version 2 is included in version 3. Version 2 is the one with the black and white logo, and version three now has the teal-colored background.
If you don’t see the Complete My Bundle option, check that you are logged in to the App Store with the same account that you bought a previous version with. Please don’t buy the bundle at the full price, because all the functionality of version 2 is in version 3. Note too that version 2 will be removed from the App Store soon, so this offer has a time limit attached to it.
Once you’ve given Photographer’s Friend a try, we’d really appreciate it if you could rate the app and leave us a review on the App Store. This really helps us to get ranked higher and make more sales!
Visit the Photographer’s Friend Technical Support page for information on updates, known issues and to contact us for help should you require it.
Apple, the Apple logo, iPhone, and iPad are trademarks of Apple Inc., registered in the U.S. and other countries and regions. App Store is a service mark of Apple Inc.
We are currently working to provide an Android version. Please subscribe to our newsletter to be updated when it becomes available, or check back here from time to time.