Pinhole Field Notebook for Exposure Calculations 

I'm setting up a spreadsheet that I can print out and stick in my notebook. I'm using f/16, because it works with everything. In the first column is the measured time from 1 to 1/1000 of a second (in full stops). Next, I have the adjusted time based on the pinhole camera's f-stop. Then, for each film where I have a reciprocity factor, I calculate the time adjusted for failure. (I also have a threshold at which the compensation is necessary, since for FujiFilm's NEOPAN 100 ACROS II it's like 2 minutes.) It has the constants and formulas in case I need to calculate something not listed. I figure it's a good starting point and I'll see how it goes. I'm going for reciprocity failure and/or slower films, because I am not confident in my ability to open a shutter for shorter durations with any accuracy.

An you share or add a link for that chart stuck to the cover of your notebook please?

Thanks, that helped a lot simplifying it like that.

Can’t you calculate the reprocity factor for tmax from the numbers in the table?

This made more sense. Thanks.