PhotoCalc for Photographers

I've been playing with a great new app for photographers from Adair Systems called PhotoCalc.  This is a very focussed utility app that does on-the-fly calculations of several key photographic measurements.

First, and to me the most important, PhotoCalc calculates de

pth of field and hyperfocal distances.  Here's a screen shot to illustrate:

All you do is input the focal length at which you are shooting, the aperture you want to use, and the distance to the subject you want on prime focus.  PhotoCalc immediately determines and shows you - for that focal length - what range of distant objects will be in focus.  For example, shooting a 50mm lens at f/4 and focusing on an object 18 feet away, everything from 14 feet-3 inches to 24 feet-6 inches will be in focus.  With so many current lenses no longer having built-in depth of field scales, this is a great way to see what changing the aperture will do for the available depth of field in a shot.

In my landscape work, I very often want great depth of field, so that objects close to the camera are in focus at the same time as objects quite far away.  One very good way to getting deep focus for these sorts of shots is to focus at the hyperfocal distance.  The hyperfocal distance is defined as the point of focus where everything from half that distance to infinity falls within the depth of field.  There are calculations you can do charts you can consult to determine hyperfocal distances, but they are generally clumsy and difficult to use in the field.

With PhotoCalc, you enter the focal length you are shooting and the f-stop, and it tells you the hyperfocal distance for that combination.  For example, shooting at 24mm and f/22, the hyperfocal distance is 4.5 feet.  So, if I focus my lens at 4.5 feet, everything from 2 feet-4 inches to infinity will be in focus.  This is so much better than trying to read a chart and interpolate from calculations at close (but not exact) focal lengths, particularly when you are standing on a windy trail at sunrise! 

My other appreciated feature is the inclusion of of Sunrise, a sunrise/sunset calculator that uses the iPhone’s ability to determine location to accurately calculate the time of sunrise, sunset and solar noon for the current day (or for any other day you select.)  Here's the screenshot for that function; again, it's completely painless and immediate.  If you also like to shoot in the "golden hours" around sunrise and sunset, this is a wonderful tool to make sure you are in the right place at the right time.

PhotoCalc will also calculate flash exposure and, for you film shooters, address exposure reciprocation by helping you trade off shutter speed, ISO, and aperture.

There is even a reference section, with a glossary and several reference documents such as the Zone System, and the Sunny 16 Rule.

I would have been glad to pay more, but PhotoCalc is only $2.99.  If you have an iPhone or iPod Touch, and want to simplify some of those messy focus calculations, this is definitely the way to go!