Today’s Question: I believe that in the past you’ve mentioned that you use an iPhone app to determine depth of field on the go. If I’m correct would you please remind me what that app is?
Tim’s Quick Answer: There are many apps available, and I’ve never found one that I’m completely happy with, but the one I currently find most helpful is called “SetMyCamera – Depth of Field Calculator” by Bluestone Pond.
More Detail: There are many apps available for various smartphones that enable you to calculate depth of field. Some are free and many are available for several dollars, and there are varying degrees of quality and usability. Some feature many in-app advertisements, and others provide a very rudimentary interface. But in general I’ve found most of them to be reasonably accurate.
It is very helpful to choose an app that enables you to choose the type of camera you’re using, so that the sensor size and circle of confusion values can be estimated automatically for you. That way you only need to enter the distance to the subject, the lens focal length, and the lens aperture to determine the overall depth of field distances.
In most cases you will be presented with the near versus far limits of the range of depth of field, as well as the total size of the area of acceptable focus for the depth of field. Often the apps will also indicate the hyperfocal distance for the current setup, which can be helpful in many cases.
I also recommend making sure that any app you’re considering includes an actual depth of field calculator, rather than a set of tables you can use to look up specific values.
And if anyone knows of an excellent app that they find to be fast and easy to use for calculating depth of field details, please let me know.