Hi there!
Recently I made the tool. I made it for myself, but see no reason not to share it.
Little comment:
All is self-explanatory, you can look inside any formula and see what is counted there. You can overwrite some values to force your own (eg. pinhole diameter). Just do not save it.
It should print nicely.
Please don't ask me of the "light falloff" formula. I'm good at maths, invented this, but I don't know if it's valid.
I've ATTACHED THE FILE (see below) and also uploaded it into the following places (If it will vanish please inform me, i'll upload it somewhere else):
You might consider posting this to http://f295.org/ as well. While pinhole calculators are quite common, I find the light fall off part of this interesting, especially from a design standpoint. Nice work, and thanks for doing this.