Reciprocity App

[awty]

Need a Reciprocity App?
Of coarse you do.
This one works well
https://play.google.com/store/apps/details?id=uk.co.monochrome.reciprocity&hl=en
Has good selection of films and what it doesn't have you could probably find a close equivalent if you can find data on your film. Also has filter factors calculator as well as bellows calculator.
Not sure of any other apps, but please post them up if you have one.

 

[Mainecoonmaniac]

Instead of an app, how about using a ruler and a chip? Take a look at this template.

http://www.waybeyondmonochrome.com/WBM/Library_files/TemplatesEd2.pdf

Look at the "Bellows Target and Rulers". It's 2 parts. The ruler to measure bellows extension and a chip, a reference square. I have it in my 4x5 camera kit. I am assuming that you're shooting large format.

 

[awty]

Ahh the good old days aye!
All the bits of paper I use to trudge along with, getting blown away, left behind in car or other camera bag, oh the joys.