Photographer’s Friend

An Assistant in Your Pocket

If you are particular about getting incredibly sharp images, you will love the new Pixel Peeper mode in our Depth of FIeld calculator! If you aren’t particular, just leave it turned off and you’ll still love Photographer’s Friend!

Two Great Calculators in One App!

Photographer’s Friend is the only app in the App Store that contains both a Depth of Field Calculator and a Neutral Density Filter Calculator. It runs on both iPhone and iPad, and in both horizontal and vertical orientations.

The Depth of Field Calculator gives you all the information you need to get your images sharp where you need it, as well as helping you to get just the right amount of sharpness in wide aperture photography. The Hyperfocal Distance field shows where you’d need to focus to get maximum depth of field, and if you tap it, the focus distance is automatically set to the hyperfocal distance, so that you can see your near and far focus limits in the hyperfocal context. We also remember your settings, so tapping the Hyperfocal Distance field again will take you straight back to where you left off.

Photographer's Friend iPadPro and iPhone

The entirely new feature-rich Neutral Density filter calculator has a built-in timer that continues to run while the app is in the background or even closed during long exposures, and with Notification Center permission we’ll display an alert when the timer ends. You can stack many of the 18 preloaded ND filters for shutter speeds up to 30 years, so it’s not only a practical tool but also an excellent way to learn or teach the effects of neutral density filters.

There are links to various interesting content, such as our Podcast as well as articles on Depth of Field, Neutral Density and the Circle of Confusion, as well as Contact Us links and other pages and articles of interest. There are also detailed built-in help pages to help you understand how to use the two feature-rich calculators.

The app is now 100% compatible with all size iPads and iPhones and works in both portrait and landscape orientations. Photographer’s Friend also works seamlessly in Split View so you can reference the calculators while studying photography or writing articles on your iPad.


ND Calc in Split View on 12.9 inch iPad Pro

In the above screenshot, I opened our article on Neutral Density filters from the Links tab and then pulled up the Neutral Density Filter Calculator from the app alongside the page using iOS Split View, so that I could do the calculations for myself. A great way to learn photography theory!


Download Photographer's Friend from Appstore


Features in Detail


Depth of Field Calculator

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).

DoF Calc with Settings Page

DoF Calc with Settings Page

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.

Quick Tips

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 Calc to get you started. To view these tips again, just tap the Quick Taps link in the bottom right of the Depth of Field visualization area.

Note that both half stop and third stop apertures are available in the Aperture dial, so it doesn’t matter which you use. It’s all there right where you need it. 

Pixel Peeper Mode

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.

DoF Calc Details Display and Settings Buttons

DoF Calc Details Display and Settings Buttons

There is also now 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.

Diffraction Warning Color Coding

Diffraction Warning Color Coding

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 Martin’s 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.

Custom Circle of Confusion

You can also now enter a custom Circle of Confusion size as a basis for Depth of Field calculation if you prefer.

DoF Calc NightView

Should you need to use the Depth of Field Calculator at night, the mainly white screen would appear bright, even with your display brightness turned right down, so we’ve built in a NightView mode. Just shake your device while in the DoF Calc tab to enter NightView, which is mainly black and red, so it won’t mess up your night vision. Note that the other tabs remain white, so stay in the DoF Calc for NightView, and just shake your device again to go back to the normal view.

DoF Calc Regular and NightView

DoF Calc Regular and NightView

Intensely Detailed

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 focal length and/or decrease focus distance to the point that you not only down to a depth of field as shallow as 0.1mm, we then switch to µm (micrometers or micron) and continue to calculate down to single digit µm. That’s 0.0001 cm. Talk about razor thin depth of field! Crazy, but fun to play with, and you never know, you might need this one day.

1.5 Micrometer Depth of Field

1.5 Micrometer Depth of Field

Neutral Density Filter Calculator

ND Calc on iPhone with Notification Center Message

ND Calc on iPhone with Notification Center Message

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 what to select. Note that shutter speeds are available in both half and third stops.

The 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 real-life, the ND Calculator allows stacking of filters for up to 30-year exposures. This is great for understanding how neutral density filters affect the shutter speed and for teaching others when necessary. As you add filters after you reached 30 years, they will be automatically removed, and if you increase the base shutter speed taking you past 30 years, we’ll remove the largest filter and display a message to let you know what we removed. When you’ve finished there’s a Reset button to clear the filters and start again.

Hide/Unhide Filters

iPhone ND Filter Hide Unhide

iPhone ND Filter Hide Unhide

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. When you finish unhiding filters, click the red button to exit unhide mode before continuing to use the ND calculator.

iPhone X Support

We’ve also tweaked the UI so that Photographer’s Friend version 2.3 or higher works flawlessly on iPhone X!

Photographer's Friend on iPhoneX

Photographer’s Friend on iPhoneX

Links Tab

On the Links tab, we’ve included a scrolling list linking to in-depth articles on Hyperfocal Distance, Understanding Neutral Density Filters, and Circle of Confusion, as well as to our Podcast and Blog, which has been released weekly for more than twelve years. 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.

Links and ND Calc HelpHelp Pages

There are two multi-page help sections with detailed information to help you understand both the Depth of Field calculator and the Neutral Density 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.

Whether you are just getting started or a seasoned professional, we think you’ll find these two calculators in one app invaluable.

Buy the App!

Pick up your copy of Photographer’s Friend from the App Store today!

Download Photographer's Friend from Appstore

Note that it is no longer possible to buy iOS apps on a PC. Please click through to the App Store from an iOS device and opt to open the link in the App Store app to buy Photographer’s Friend.

Scan and Go!

If you can scan a QR code, this will take you to the app page on the App Store!

Photographer's Friend QR CodeRate and Review

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!

Technical Support

Visit the Photographer’s Friend Technical Support page for information on updates, known issues and to contact us for help should you require it.

Free for Version 1 Users!

If you bought version one (the MBP Podcast Companion App), we’ve made v2.0 a free upgrade. If you already uninstalled the first version of the app because it was outdated, you can reinstall it from the App Store at no cost, or go to your Account in the App Store then navigate to Purchased > My Purchases > Not on this iPhone/iPad and look for Photog’s Friend in the list.

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