Martin Bailey

Photography

Photographer • Podcaster • Tour Leader • Mentor • Capture One Ambassador • X-Rite Coloratti

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Calculate how much of your scene will be in focus!

Depth of Field

See why it's amazing!

Customize your list and stack ND filters!

Neutral Density

Take a look

Learn how camera settings affect exposure

Exposure Shift

Show me!

The only app with truly accurate DoF info!

Pixel Peeper Mode

See why

Helps you to both learn and teach photography

Practical & Educational

Here's how

Shake your device to toggle between themes!

Light & Dark

See details!

An Android version will be here very soon!

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Photographer's Friend III

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).

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.

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 your depth of field is as shallow as 0.1mm, and then we switch to µm (micrometers or micron) and continue to calculate down to 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.

$MBP_DOFCalc_Diffraction_Warnings$

Pixel Peeper Mode

The first difference is that the calculated depth of field is somewhat shallower in Pixel Peeper mode. This means that you actually have to use a smaller aperture or wider focal length to gain adequate Depth of Field.

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!

In Pixel Peeper Mode we recalculate your actual Depth of Field based on your camera's sensor size and megapixels, from which we calculate the Pixel Pitch, Airy Disk size, and Circle of Confusion size.

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 the Diffraction Warnings are intended as a guide, to show you when there is a possibility of diffraction. We recommend that you 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.

Exposure Shift Calculator

When changing 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!

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.

The huge range of apertures and ISOs are great for educational purposes. We also included a settings screen to set the upper and lower limits of each dial to match your camera.

Neutral Density Filter Calculator

Enter the shutter speed that you need to get a standard exposure without filter, then tap the filters that you'll attach to your lens and the ND Filter calculator will display your new shutter speed.

A timer is available for shutter speeds of 5 seconds or more. 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 and we’ll display an alert when the timer finishes.

You’ll ever need this in real life, but 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.

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 necessary. When you finish unhiding filters, click the red button to exit unhide mode.

An Invaluable Education Tool!

We’ve included a scrolling list of links 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 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 also a link to our Photographer’s Friend Video Tutorials page, with a video to explain how each calculator works.

Photographer’s Friend is an invaluable education tool to both learn and teach photography.

It 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!

Light and Dark Themes

From version 3.2 there is a stylish Dark theme in addition to the updated Light theme, and all you have to do to switch is shake your device! This is only available on devices running iOS 13 or higher.

The Dark mode looks stunning, and although the Light mode is perhaps easier to read for some people. If you want to have the theme match your devices chosen Appearance, shake it until you see the message "Device Theme Active".

These themes replace the old Night View, but now every element of Photographer's Friend is themed, including the settings screens and all of the help screens.

At the same time, we developed a brief messaging system that displays the theme mode as you toggle between them, but we took that a step further and use the feature to display messages when you access Photographer's Friend, to alert you when the app is updated, and also some random welcome messages for fun. We hope you enjoy them!