As a long time lurker of these forums, I was encouraged by koraks to participate more in the discussions here. I recently got started in LF with a Toyo 45A and am still in the process of finding my own workflow. Part of this was having to correct for bellows extension and reciprocity failure. Doing it by heart get annoying quickly. Being a bit of a nerd, I decided to give app development a go and what better than make an app that is useful to me in the field too .

The end result is a free Android app called Inverso (Android 4.0.3 and up) that helps in correcting for bellows extension, filters and reciprocity failure for continuous light, flash and a combination of both. It also includes a timer function that offers an optional delayed start and audible start/stop warnings, so you don't have to start the timer and fire the shutter at the same time.



The full description of the functionality and a list of the included film stocks can be found here: http://printerattic.com/inverso/

You can find it in the Play Store here.

I am in the process of expanding it further and trying to find reliable data for Ilford films. If you have some, I'd be happy to incorporate it!

Let me know what you think and how you think it can be improved further.

Roy