Photographer's Friend has three excellent photography calculators in one application, and now with two of them available for Apple Watch with almost full feature parity! We believe our Depth of Field Calculator with the Pixel Peeper mode turned on is the most accurate and detailed DOF Calculator available!

Depth-of-Field Calculator
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Calculate the Depth of Field in your photographs based on your camera's sensor size, aperture, focal length, and focus distance, set with four dials along the base of the DoF Calc.

The display includes your Hyperfocal Distance, which can be temporarily transferred to the Focus Distance dial or locked for continuous updates. Display distances in metric units or feet and inches.

By default, we use traditional Depth of Field calculations, but Pixel Peeper mode calculates Depth of Field using your sensor size and megapixels for higher accuracy. You can also enter a custom Circle of Confusion size if you prefer. There's even a diffraction warning mode!

Diffraction Limit guides adjust the color of the Aperture guide when there is a possibility of Diffraction. You can change the Diffraction Limit guide starting points as part of the Pro Add-on available as an In-App purchase.

Neutral Density Filter Calculator
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Enter your base shutter speed into the Neutral Density Filter Calculator to calculate your new shutter speed after fitting ND filters to your lens. Filter labels include the multiplication factor (ND2, ND4, etc.) with f-stop and optical density values also displayed. You can hide filters that you don't use or bring them back again with slide gestures.

A timer is available for shutter speeds of 3 seconds or longer, so if you don't have a timer switch or built-in timer in your camera, we'll time your exposure for you!

Exposure Shift Calculator
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When changing your camera's exposure settings, 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? How does it affect your ISO? The Exposure Shift Calculator has the answers!

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 the other free dial automatically, or turn on Exposure Value Lock to have Photographer's Friend calculate all settings for you!

Additional Features as In-App Purchases
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Photographer's Friend is fully functional at the marked price. However, several features such as Apple Watch Extensions and some Pro features available as In-App Purchase as they may not be of interest to everyone. There is also a bundle to save on the multiple individual Add-ons.

Links
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We've included links to in-depth articles on Hyperfocal Distance, Understanding Neutral Density Filters and Circle of Confusion, the Airy Disk and Diffraction, and Understanding Exposure Value, among other helpful content. We've also provided a link to online tutorial videos to walk you through each calculator and the optional Apple Watch Extensions.

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 add it in a future update.

Onboarding Help
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Depth of Field, Neutral Density, Exposure Shift Calculators, and some settings screens have onboarding help with interface element highlighting to help you get to know your new Photographer's Friend.

Whether you are just getting started or a seasoned professional photographer or educator, we think you'll find Photographer's Friend invaluable!