Edge markings on 120 film

twinsfan · Dec 22, 2009

Hi Everyone,

Silly question, but I noticed on 3 rolls of Kodak film that I've had processed there are numbers on the edge of the film. Each roll begins with 41 and ends with 55. This is on the opposite side of the film that has the frame numbering and arrows, it's interspersed with the words KODAK 400TMY-2 (in the case of Tmax 400) or KODAK E100VS (in the case of 100VS). Anyone know what those numbers refer to?

photomem · Dec 22, 2009

Those could be numbers superimposed by the processing machine at your lab. I noticed them when I used to have Dixie Color (Gone Now, but sorely missed in Memphis) processing my film when I first moved to town. Now I have to use Memphis Professional Imaging and no strange numbers printing. Just a thought.

twinsfan · Dec 22, 2009

I don't think that's it, they are from 2 different labs, and it's in the same font as the Kodak markings.

naugastyle · Dec 22, 2009

I think it's just a Kodak thing, although I'd love to know the meaning behind it. I have these numbers too on 160NC, home-processed. Nothing like this on home-processed 400H, 800Z, Acros, Delta 3200. I might dev a roll of TMY tonight and see if it's the same.

michaelbsc · Dec 23, 2009

naugastyle said:
I think it's just a Kodak thing, although I'd love to know the meaning behind it. I have these numbers too on 160NC, home-processed. Nothing like this on home-processed 400H, 800Z, Acros, Delta 3200. I might dev a roll of TMY tonight and see if it's the same.

My guess would be that it's something to do with tracking the packaging process. If dozens of rolls come back as defective with "these particular numbers" they can most likely determine when/where/who/how.

naugastyle · Dec 23, 2009

But if ALL the tracking numbers are 41 - 55, how does that help? I suppose it could be coincidence, but three different films? (TMY and E100 for twinsfan, 160NC for me).

MattKing · Dec 23, 2009

All of the Kodak 120 film I shoot (Plus-X, TMX, TMY, E100 and Portra) has these numbers. They are alternate frame numbers - if you shoot 6x4.5, they line up correctly with the frames. If you shoot 6x9, you get two numbers per frame.

I don't have any idea why they chose 41-55, but it certainly makes it easier to specify negative numbers to your photofinisher.

IIRC they have done this for as long as I have shot 120 - since the 1970s.

I don't have any 220 negatives handy, but I think they do the same or a similar thing with them as well.

Matt

Sirius Glass · Dec 23, 2009

If you print contact sheets, the numbers can be associated with the negative so that it is easier to pick the right one when a number of shots have been taken of the same subject/scene.

Steve

msage · Dec 24, 2009

MattKing said:
All of the Kodak 120 film I shoot (Plus-X, TMX, TMY, E100 and Portra) has these numbers. They are alternate frame numbers - if you shoot 6x4.5, they line up correctly with the frames. If you shoot 6x9, you get two numbers per frame.

I don't have any idea why they chose 41-55, but it certainly makes it easier to specify negative numbers to your photofinisher.

IIRC they have done this for as long as I have shot 120 - since the 1970s.

I don't have any 220 negatives handy, but I think they do the same or a similar thing with them as well.

Matt

Matt is correct, I remember when they first started doing that. There was a Kodak publication that stated so.
Michael

stm · Dec 25, 2009

I see the same thing on the top edge of 120 T-Max 100. I am clueless as to what they mean. I shoot almost exclusively with my A-16 (6 x 4.5) backs have no idea what they correlate to; certainly not to 16 frames per 120 roll.

I have just come to totally ignoring them. Like they say in the Bud commercials, why ask why?

John Shriver · Dec 29, 2009

Maybe they start at 41 so there's no possibility that they will be confused with frame numbers on 35mm film? The normal rolls go up to 37, bulk load film goes up to 40, so you'll never see 41 or higher on 35mm film.

dokko · Nov 15, 2023

this is an old thread, but since it came up in another one, I thought it might be good to add the info here:

I'm pretty certain that the additional numbers are to avoid ambiguous guesses about which frame we mean when we write down a frame number for communication.

like on 35mm film, there are markings 1 | 1A | 2 | 2A | 3 etc. the reason is, that if the number by accident is exactly in between two frames, you can still use the other number to make it totally clear which frame you're talking about.

120 film makes things more complex since there are different formats (6x4.5, 6x6, 6x7, 6x8, 6x9 etc) and camera loading and transport differ as well. so chances are high that a number falls in between frames sometimes.

now they could just have printed tightly spaced numbers from 1-100 on each roll and there would be enough definitive ones to choose from, but I guess for historical/compatibility reasons they decided to stay with 1-12 on one side and add a second set of clearly different numbers on the other side of the film.
if you look closely, you'll notice that they are carefully arranged that they are always offset slightly, to make sure that there is no spot on the film where you could have no definitive number (well, unless you shoot something like 6x2).

koraks · Nov 15, 2023

dokko said:
if you look closely, you'll notice that they are carefully arranged that they are always offset slightly, to make sure that there is no spot on the film where you could have no definitive number (well, unless you shoot something like 6x2).

I think the rationale here is that the numbers 1 ~12 are at roughly 6cm frame space intervals (covering 6x6 and 6x12 taking formats) while the 41 etc. numbers are at roughly 4.5cm frame space intervals (covering 6x4.5 and 6x9 formats). I guess the 6x6 numbers are close enough to the 6x7 frames to not cause much trouble and 6x8 is probably considered rare enough to not bother with them (?)

dokko · Nov 15, 2023

koraks said:
I think the rationale here is that the numbers 1 ~12 are at roughly 6cm frame space intervals (covering 6x6 and 6x12 taking formats) while the 41 etc. numbers are at roughly 4.5cm frame space intervals (covering 6x4.5 and 6x9 formats). I guess the 6x6 numbers are close enough to the 6x7 frames to not cause much trouble and 6x8 is probably considered rare enough to not bother with them (?)

yes, it seems very likely to me that the 1-12 frame numbers were designed for 6x6 cameras. but even there we could run into trouble: imagine we'd wind the camera a bit too much when loading the film, so the first picture falls in between markings number 1 and 2, and the second falls in between markings 2 and 3. worst case pretty much the whole film would be like that.

with larger formats (6x7 and up) it seems impossible that we have a picture where there is no definite markings underneath the frame - in fact we'd usually have two numbers belonging to one image.

with 6x4.5 we'd have quite a few frames with no numbers at all, which obviously is a problem.

so clearly more numbers are needed. as mentioned they could have just added more and tighter spaced numbers on only one side (or use the same 1 | 1A | 2 | 2A .. method as in 135 film), but there must have been a good reason not to mess with the 1-12 numbering, so adding another set of numbers on the other side was probably preferable.
starting with 41 most likely was to make sure it was high enough not to cause problems with 220 or even longer film and still stay within 2 digits.

koraks · Nov 15, 2023

dokko said:
but even there we could run into trouble: imagine we'd wind the camera a bit too much when loading the film, so the first picture falls in between markings number 1 and 2, and the second falls in between markings 2 and 3. worst case pretty much the whole film would be like that.

Yes, true. But I think most cameras out there will make your frames line up fairly well with the numbers on the film as long as they're mechanically in good working order, and used properly. Since frame spacing tends to vary a bit across the roll on most/many medium format platforms, there's often a little shift/slip, but in practice, this doesn't result in confusion, I think.

Not sure if 6x4.5 runs into trouble with the 41 etc. numbering. I'd have to dig up a roll I shot with my m645 on Kodak film.

MattKing · Nov 15, 2023

6x4.5 spacing nicely matches the 41, 42, 43, 44 ... frame numbers - as does 6x9 (every 2nd number).
6x7 and 6x8 don't match any frame numbers, but the 41, 42, 43 numbers end up being more useful.

dokko · Nov 15, 2023

koraks said:
Yes, true. But I think most cameras out there will make your frames line up fairly well with the numbers on the film as long as they're mechanically in good working order, and used properly. Since frame spacing tends to vary a bit across the roll on most/many medium format platforms, there's often a little shift/slip, but in practice, this doesn't result in confusion, I think.

that's certainly true with most modern cameras, but there are quite a few old cameras where you have to wind manually (sometimes even by aligning the frame with a number on the backing paper through a peak hole in the camera back). so things easily can go wrong.

koraks said:
Not sure if 6x4.5 runs into trouble with the 41 etc. numbering. I'd have to dig up a roll I shot with my m645 on Kodak film.

well, the beauty of the current system is that even of we are unlucky and a 6x4.5 frame will fall between two of the higher number (let's say between "43" and "44", maybe because of a transport malfunction) there's always another number on the other side (in this case "3").

it might not be very elegant to give the lab the numbers like:
"I'd like to print frame numbers 41, 3, and 49"
but it's much better than:
"I'd like to print frame numbers 41, the one between numbers 43 and 44 and 49" (specially once the film is cut up in stripes, or even worse, single frames because of drum scanning or slide projection).

MattKing · Nov 15, 2023

Don't forget that the Kodak numbers have the "A" numbers half way between the 6x6 numbers - 1 - 1A - 2 - 2A - 3 - 3A .....
I've never found a negative where there wasn't a reasonable solution.

koraks · Nov 15, 2023

dokko said:
but there are quite a few old cameras where you have to wind manually (sometimes even by aligning the frame with a number on the backing paper through a peak hole in the camera back). so things easily can go wrong.

Both the types of cameras that expect you to wind manually to the 'start here' indicator and the ones that wind using the red window in the back tend to line up perfectly on the first frame. Especially the ones that rely on the backing paper numbers will give absolutely perfect alignment with the film edge print.

As to how labs handle this, these days - I really wouldn't know. It's ben a loooong time since I had a lab print any of my film, and if I recall correctly, the last time it happened, it was because I filled out the form incorrectly - I just wanted them to develop the film!

dokko · Nov 15, 2023

koraks said:
Both the types of cameras that expect you to wind manually to the 'start here' indicator and the ones that wind using the red window in the back tend to line up perfectly on the first frame. Especially the ones that rely on the backing paper numbers will give absolutely perfect alignment with the film edge print.

I know, but I have to admit that I've missed the start mark or the proper next frame quite a few times I could imagine others have too, specially since those were amateur cameras to a large extend.

dokko · Nov 15, 2023

MattKing said:
Don't forget that the Kodak numbers have the "A" numbers half way between the 6x6 numbers - 1 - 1A - 2 - 2A - 3 - 3A .....

hmm, I just checked with a current T-Max 100, T-Max 400 and Portra 160 here, all of them only have the full 1-12 numbers and no in between A numbers.

checking a current Lomography 400 and 800 Color Neg, it looks like they went the route of simply adding more numbers and used 1-18 on both sides.

MattKing · Nov 15, 2023

I just realized I was thinking of the 135 numbers - oops!

Sirius Glass · Nov 15, 2023

The numbers to location mapping is not all that important. What is important is that there are numbers which the photographer can communicate to the photo finisher which negative to print. To purpose of the numbers is communication which negative(s) are of interest.

koraks · Nov 15, 2023

Yes, @Sirius Glass, we know. And the debate has since shifted to what potential pitfalls hide in that process.

Edge markings on 120 film

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