Who Decided 35mm Film Comes in 24 or 36 Exposures?

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wgerrard

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So... why do we have 24- and 36-exposure rolls of 35mm, or 12 of 120? Why not something else? Why not 96-exposure rolls of 35mm?

Is there a reason? Someone's quick choice decades ago?

Or do the rolls get too fat?
 
It used to be that film came in either 20 or 36 exposures. From time to time there have been 12 exposure rolls of 35mm film. And there was a Leica model that could accomodate a much larger roll of 35mm film. But if you have ever tried to load film onto a developing reel, you may agree with me that 36 exposures is enough.
 
120 is not 12-exposure, per se. It is a certain length of film, which was likely established based on 6x9 format. It is 8 exposures at 6x9, 10 at 6x7, 12 at 6x6, and 16 at 6x4.5 (half-frame).
 
and for a while Ilford sold their HP5 in 72 exposure, on a special thin film base.
 
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And at a certain point, you couldn't get more film into the spool, unless you made a very thin base. Ilford did this some time back. As I recall, they had a 72-exposure roll. Just think of that with half-frame -- it could take you a couple of years to fire off 144 exposure.
 
I don't have any confirmation, but I have heard from more than one person that 36 exposures was the longest film Barnack could wipe down after development.
 
A friend of mine was given some rolls of 8 exposure Kodak film that his uncle had in the freezer. He was a real estate agent and they would use them to shoot each house... one house per roll so they never got stuck midway in a roll or 24 or 36.
 
I used to bulk load my own Tri-X, and I could never get more than 40 on a roll. Plus, I often ended up being unable to crank the dang thing and rewinding was a real bear. So I tended to stick with 36.
 
ZeissFan said:
And for a while, Agfa sold their color film as "24 + 3" -- not 27, but "24 + 3."
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I think Foma might have as well, my friend John in England did not like the 24+3 as the processing people charged a lot more for anything more than 24.

I tried bulk loading a bit longer than 36, and it sometimes caused scratching on the base.

First bulk film I had was Tri X, but I had no loader, so the first roll was loaded all by hand, I used to feed the film on to a developing reel to make sure it was not too long. Kodak cartridges had pop off ends. Last pop off ends I have seen were Foma a few years back.

I see Tom A in his You Tube video on bulk loading uses a basic length measurement system. ;-)

I also recall the first cartridges you could buy loaded, post dated the first Leica Cameras, so I assume the design of the cartridges was related to the camera. Am not sure when the loading tongues were shortened, making it necessary to trim film leaders for loading in SM Leicas.

Kodak used paper "cans" and later really nice metal screw cans in various colors to denote the film types. Agfa cans were sealed with tape, and the cartridges were closed differently than the Kodak Snap Ends.

I have a feeling more bulk film will be in our futures.

Regards, John
 
Leica set the standard and Kodak introduced it as a 135 cartridge.

Barnack set the 36 exposure standard somewhat arbitrarily; as mentioned earlier 36 exposures is ~5 feet. Remember, the Leica was originally conceived in 1914 as an instrument to batch test movie film and not as the popular camera we know now. Apparently, five feet was a good length to test. As I recall the Leica later became commercially available as a camera in 1925.

Kodak introduced the 135 cartridge with the original Retina in 1934. Until that time the cartridges (usually brass) were handloaded, either from bulk or 36 exposure "handload" strips with a paper leader attached. 36 exposures became the standard, 18 was offered in 1939 and after WWII the film industry settled on 20 and 36 until much later when 20 became 24.
 
I read somewhere that 36 exposures was the length of stretched arms (i.e. when Barnack took movie film to use as film for his first still camera).

Could just be urban myth, but I'm convinced :)
 
Yeah Hung, that's true my friend, I read this from the book "Leica Witness to a Century" if I'm not mistaken :p

hunghang said:
I read somewhere that 36 exposures was the length of stretched arms (i.e. when Barnack took movie film to use as film for his first still camera).

Could just be urban myth, but I'm convinced :)
Click to expand...
 
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