Why 24 exp, 36 exp ?

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35mm film began with Ur-Leica.

Any one knows what was the original exposure number of Ur-Leica ?

Why standard 35mm film has 24 exposure or 36 exposure ?

Where this numbers 24, 36 comes from, in order words, was there any particular reason this numbers was chosen ? Say, a box of glass plate contained 24 plates etc ?

-- martin tai (martin.tai@accessv.com), March 02, 2002

Answers

Actully, when I got back into photography seriously a few years ago, I was shocked to find 24-exp rolls. In my previous photographic incarnation in the '70s the standard sizes were 36 and 20. To my mind this made a bit more sense, because when I wanted a short roll I usually don't need 24 frames, so the 20's were more economical. I suspect the 24 exposure roll was driven by the amateur vacation- snapper market, where a 36 is just too long but 20 is a bit too short.

the difference is in perspective - people like us shoot a lot, so we tend to see the 36-exposure roll as standard, and the 24 as "short". The average Joe sees the 24 as standard and the 36 as "long".

As to how the 36-exposure roll became standard, I have no idea. My speculation is that it was simply convenient - long enough to give a lot of exposures, and just the right size to fit into a cassette that would fit into a the camera body.

-- Paul Chefurka (paul@chefurka.com), March 02, 2002.


I think the original UR Leica's frame counter went to 50, which as Paul said, was probably the longest length that would fit in the camera. I have the impression that the UR had to be loaded in darkness and simply held "loose" film with no cassette. Anyone know for sure?

But with a cassette, 36 is about the longest length that will easily fit inside, but it also happens to be a nice even length of 5 feet or 1.5 meters.

I have among my collection of oddities an old Kodak catalog from 1938. It lists 35mm BW film available in two sizes, 18 or 36 exposures. So the short size has gradually been growing from 18 to 20 to 24. Then some made 12 or 27 exposure rolls.

Just for interest and comparison, the film prices from 1938 were (in US dollars):

Plus-X, Super-XX & Panatomic-X 18 exp: $0.60 Plus-X, Super-XX & Panatomic-X 36 exp: $0.95 Kodachrome slides 18 exp: $2.50 with procssing.

In 1938 the US instituted the first minimum wage of $0.30 per hour, which today is around $5.50 (not exactly sure), so you can figure the relative effect of inflation over the last 65 years.

-- Tod Hart (tghart@altavista.com), March 02, 2002.


Thank your Tod for a piece of very interesting: Ur-Leica counter = 0- 50

That explains why early Minox Riga, II, III, IIIs and B all had 50 exposure counter !

-- martin tai (martin.tai@capcanada.com), March 02, 2002.


When out travelling, I always carry 36 exp film, to cut down film change time.

It is also cheaper to process 36 exp film vs 24 exp film, on per 4x6" print basis

-- martin tai (martin.tai@capcanada.com), March 02, 2002.


Using similar Bureau of Labor Statistics CPI inflation indexes from 1938 to 2002 (good thinking Tod) $1 back then is equivalent to $12.56 2002 A.D. dollars.

So a 36 exposure roll of black and white film was a bit over $11 in today's money and an 18 exposure roll was about $32 in today's money. Or $64 for 36 slides.

Very expensive, when you consider that real incomes were significantly lower then, i.e. even after adjusting for inflation.

No wonder my Dad constantly mutters about my "wasting film" when he sees me snapping away, modern amateur style. And no wonder photography had this reputation for being an expensive hobby.

-- Mani Sitaraman (bindumani@pacific.net.sg), March 02, 2002.



BTW, a roll of 36 exp print film printed on Fuji Crystal Archive 4x6" cost only C$7.99 that is about US$5, and 24 exp processing cost C$5.99. Good color, using latest Fuji film processor, very good price.



-- martin tai (martin.tai@capcanada.com), March 02, 2002.


Since print film processors charge by the print they just make more money with a 24 exposure roles which usually have 25 or 26 exposures. I shoot 36 exposure Velvia but when I need print film I've discovered 12 exposure "sample" rolls at Ritz for under $2.00. I can do an entire family reunion with 12 exposures - no wasted film.

-- gerald (sanford@usa.com), March 02, 2002.

Tod, is right about the UR and 50 exposures - however this applied only to a direct loading of loose film in the pre-production UR model.

The addition of the necessary (re-loadable) film cassette holder in production cameras brought the aimed for number of exposures down to 40 - this caused problems however and it was found that 36 exposures fitted far more reliably. Hence all new Leica's were sold with three cassettes holding 1.6 metres of film (or 36 exposures worth).

Remember, it was the sucess of the Leica that created a market for the pre-loaded film cassettes that we still use today.

Source:"A history of the 35mm Still Camera" Roger Hicks

-- Giles Poilu (giles@monpoilu.icom43.net), March 02, 2002.


I can remember Kodak putting 35mm in 12 exp rolls. Seems like 15 or 20 yrs ago. I welcomed this until I discovered that it costed as much to develop the 12s as it did for the 24s! The 12s soon disappeared from dealer shelves. The beauty of 35mm is that you can afford to shoot 3 or 4 different exposures of the same subject and then pick out the best for printing. This gets expensive with medium format.

-- Frank Horn (owlhoot45@hotmail.com), March 02, 2002.

I picked up a role of 12 in a Italy a year and a half ago, very practical at times.

-- Margaret (fitz@neptune.fr), March 02, 2002.


Martin sys: "35mm film began with Ur-Leica."

Just to clarify that Leica did not invent 35mm it was already around for about 30 years in cinema cameras. Leica saw the potential for using it in still cameras so for a number of years the film used in Leicas was from the cinema film stock, then Kodak started to package 35mm for still cameras. Some people today still will buy a 400' or 1000' roll of cinema stock and load their own cassettes.

-- Steve leHuray (steve@icommag.com), March 02, 2002.


For those with an historical bent, Leitz used to make a camera called the Reporter (models FF and GG, aka. Leica 250) that was built to handle bulk loading film cannisters for 250 exposures. This is now a collectors item. There are also off shoots of the Leica 250 (? Russian), some of which are pictured in Lager Volume I, that could hold 500 or 750 exposures. The Leica 250 is rare today, because it wasn't a great commercial success and few were made. However, it does indicate that Leica's thinking went beyond the standard 36 exposure cassette.

-- Eliot (erosen@lij.edu), March 02, 2002.

Agfa likes to sell oldball number film. They have 24+3 Vista, HDC, and one time had 10 exp HDC 400

-- martin tai (martin.tai@capcanada.com), March 02, 2002.

In lastest issue of Popular Photography there is a picture of several early 35mm cameras, all predated the 1925 Leica. The earliest none Leica 35mm camera was a 1914. However Ur-Leica was built 1913.

Looks like Ur-Leica was still the earliest 35mm still camera

-- martin tai (martin.tai@capcanada.com), March 02, 2002.


35mm film itself (introduced in the 1890's) was generally believed to be derived from 70mm Kodak movie rollfilm (slit in half). The first commercially available 35mm still camera was not the Leica but the "Tourist Multiple" (patented 1912) and slightly later, the "Simplex".

The Tourist was half frame only but the Simplex was switchable from half to full frame and held 50 feet of film! (400 full exposures).

A further ten or so 35mm camera's were introduced before the Leica in 1925 - the Leica did however put 35mm on the map, being the first well engineered, compact, precise and ergonomic camera to do the format justice.

-- Giles Poilu (giles@monpoilu.icom43.net), March 02, 2002.



Slightly off-topic...

In Japan, you can get 120 film in 4 exposure lengths (assuming 6x9 shots)!

-- Mani Sitaraman (bindumani@pacific.net.sg), March 02, 2002.


Actually, 36 is (3)6's, the sign of the antichrist. The film size is 24x36. 24=2x12, 36=3x12. 24+36=60 (HA). The ratio of 24x36 = 1:1.5. Think about, the end is near, repent!

-- Glenn Travis (leicaddict@hotmail.com), March 02, 2002.

12, 24, 36. 1 dozen, 2 dozen, 3 dozen. Lots of things were (and still are ) marketed in dozens. Could it be that simple? Cheers,

-- Tim Gee (twg@optushome.com.au), March 02, 2002.

6 film strips of 6 frames full fill a 8x10 contact sheet...

-- r watson (al1231234@hotmail.com), March 02, 2002.

With thin base film, more exposure can be packed into a 36 exp cartridge. Ilford used to market 72 exp film.

Any one tried loading more than 36 exp Kodak TEchnical Pan film in to cartridge ? I never try this with 35mm film, but do this all the time loading 50 exp TP film into 36 exp Minox cassette.

I expect a 35mm cartridge can hold up to 50 exp Technical Pan

-- martin tai (martin.tai@capcanada.com), March 03, 2002.


Martin, while you wonder where they got the idea for 24 or 36 exposures, I wonder where Minox got the idea for 15 exposures (the short roll)? Now that's weird!

-- Bob Fleischman (RFXMAIL@prodigy.net), March 03, 2002.

Bob, very good question.

Since there was no 15 exp 35mm film, where the Minox engineers got the idea of 15 exp short film.

-- martin tai (martin.tai@capcanada.com), March 03, 2002.


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