The Iowa City Camera Club is an N4C (North Central Camera Club Council http://n4c.us) Small Camera Club.
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Johnny Brian johnnybrian.com
Today I’ve been binary encoding my film holders — this involves cutting notches into the flap at the end of the holder so that when the film is exposed, the notches create a unique pattern on the film so I can identify the film holder used for each exposed sheet of film. I chose to use binary numbers — binary is perfect as its all 1 or 0 — so notch present or absent — and I can encode up to 63 holders with just 6 notches. Some who are astute with math might say, 2^6 = 64, but I did not want to use number 000000, as it would be indicated by no notches. If I ever go over 63 (unlikely, that’s a lot of film holders) I will only need to add a seventh notch, and then i can encode up to 127 holders. I have ruler guide that I made — its important to have the notches in a defined location so they can later be read. The notches start 1 inch from the right edge and are spaced at 1/4 inch intervals.
One issue with encoding film holders is that they need to be empty, but I have been shooting some 4×5 lately, so some of the holders are empty. I have about 6 or 8 more sheet of film to develops, so I will have some more empty holders soon. So far, I have over half of my holders marked.
Legend for images
Guide that I use to position the notches.
Guide in place against right side to place notches.
New notches — its important not to damage the outside of the flap as that is what forms the light seal.
It always good to have a vetting system when you are about to make irreversible changes.
How to read notches.
Reading notches from film.
EXTRA BONUS POINTS — What in which number film holder was this sheet exposed?