Pinhole Field Notebook for Exposure Calculations

Following from the last video, here is how I set up a field notebook to store all my information about pinhole camera exposures

[@RickLeMon]

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.

[@ebreevephoto]

This made more sense. Thanks.

[@franklittle6702]

Thanks, that helped a lot simplifying it like that.

[@petergoodrum1607]

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

[@key2adventure]

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

[@adamleszko1588]

sure you can...
for t-max 400 and numbers from the table, it's somewhere between 1.10 and 1.14 (growing for longer shutter times)