Curious - how long can exposed film be left undeveloped?

[Don_ih]

The fog, however, affects the effective speed; it limits how far down in the shadows you can see details. That's the real cause (IMO) of the speed loss we see in very old unexposed film, too -- just takes more light to get above the base + fog.

I have Tri-X ortho from around 1970 that has very little fog but is now around iso25. My experience is faster films slow down faster even if the base fog doesn't come up that high.

 

[Donald Qualls]

Tri-X ortho from around 1970 that has very little fog but is now around iso25.

Hmm. Good to know, I've got an unopened box of that (4x5). Still likely to be fun...

 

[Huss]

Outside of Pan F+, I would say that unless you were thinking about interplanetary travel, I wouldn't be overly concerned about the time frames involved.
Damage due to storage and handling issues are of much greater concern.

Now you're making me think about cosmic rays....

 

[logan2z]

...unless you were thinking about interplanetary travel, I wouldn't be overly concerned about the time frames involved.

Hmm, but if you were traveling near the speed of light and took your film with you, it would age much slower relative to film on earth.

I knew that the special theory of relativity would finally come in handy one day

 

[MattKing]

Now you're making me think about cosmic rays....

I'm sure that where you hang out, there are lots of places to get tinfoil hats

 

[MattKing]

Hmm, but if you were traveling near the speed of light and took your film with you, it would age much slower relative to film on earth.

I knew that the special theory of relativity would finally come in handy one day

I always enjoy adding Michelson-Morley into a discussion, just to see what happens.

 

[logan2z]

I always enjoy adding Michelson-Morley into a discussion, just to see what happens.

I didn't think that one would come in handy aether

 

[Donald Qualls]

I always enjoy adding Michelson-Morley into a discussion, just to see what happens.

My experience is that they don't seem to care what direction the wind blows, but they always interfere.

 

[KerrKid]

Loss of speed from age doesn't impact an image that's already been captured on the film. Fog, however, does. The main reason to process the film as soon as possible is because it's no longer in its factory-sealed container, may have been exposed to moisture or other conditions that are bad for the film. The film can only possibly degrade from that point on (as in, it can't get better) so there's no point waiting to develop it.

This roll of film was in a bunch of stuff I bought. It was Tri-X 35mm, shot who-knows-when. I developed it - but the problem was it was likely pushed and the negatives ended up very thin. If I'd developed it a few minutes longer, it would have been much better.

View attachment 320189


I also developed a film pack that was shot in the mid 50s. The images were on there fine but the emulsion suffered from exposure to the paper and age fog.

Great shot. Well worth having even if it looks like this. Reminds me of similar pix I have of myself back in the mid-70's.

 

[Don_ih]

Hmm. Good to know, I've got an unopened box of that (4x5). Still likely to be fun...

Just to let you know, it was almost iso100 in Diafine.

 

[Huss]

I'm sure that where you hang out, there are lots of places to get tinfoil hats

We hold them under our chins to get an even tan.

 

[Juan Valdenebro]

Apart from PanF+, underexposed film (for pushing) should be developed within days too, for best results.

 

[Romanko]

Here's an example of Kodak Verichrome type 127 with the process-before date of November 1946. Developed in April 2022 in HC-110 dilution B at 7 degrees Celsius for 10 minutes. I did a strip test and aimed for lower density but the negatives are still pretty dense due to fog.

I would not recommend storing unprocessed film for more than 50 years.

 

[braxus]

I shot some rolls of Efke 25 over a month ago and another 1 over 1 week ago. I haven't gotten around to getting them developed yet. Last week, I just mixed up a new batch of Xtol, so maybe Sunday I'll get to it. I don't imagine the Efke rolls will be bad in any way.

 

[Andrew O'Neill]

I shot some rolls of Efke 25 over a month ago and another 1 over 1 week ago. I haven't gotten around to getting them developed yet. Last week, I just mixed up a new batch of Xtol, so maybe Sunday I'll get to it. I don't imagine the Efke rolls will be bad in any way.

You'll be find, Scott. My experience is with the sheet film version. I developed some that were (embarrassed to say) "several" months old after exposure, and they were fine.

 

[pentaxuser]

Apart from PanF+, underexposed film (for pushing) should be developed within days too, for best results.

What is it about underexposed film that means it should be developed within days and how far does this extend into the realms of underexposure i.e. in terms of stops?

Thanks

pentaxuser

 

[Juan Valdenebro]

It's about the darkest tones (on paper): those receive -on negative- an amount of photons that's just a small fraction of the amount films are designed for, so those parts of the latent image have a tendency to fade quickly, in a few days...
Years ago I saw a test on it: a pushed roll shouldn't be done through several weeks.
Of course the zones of the negative where more light hit, won't suffer to the same degree.

 

[albada]

What is it about underexposed film that means it should be developed within days and how far does this extend into the realms of underexposure i.e. in terms of stops?

Here's a test of latent image stability (by @Stephen Benskin ) in which film was developed ranging from 30 seconds up to 31 days after exposure, and the ISO of the film measured for each. Developing after a few hours produced an ISO of 78, but after 31 days the ISO had dropped to 65.
A surprise was that developing only 30 seconds after exposure yielded an ISO of 94, so it seems that much loss of latent image occurs soon after exposure, and then there's a slow loss after that.

 

[pentaxuser]

Thanks for the link, albada.

Juan can you recall the test you saw and provide the link and was there any mention in the test you saw as to how the extent of underexposure affected the shadows ?

Thanks

pentaxuser

 

[MattKing]

It is really quite straightforward. An under-exposed negative has less of a latent image, and that latent image has less information in the shadows. So when the delay results in the latent image starting to fade or become subsumed in fog, the shadow detail becomes less and less accessible. Less shadow detail = less speed.

 

[Juan Valdenebro]

Thanks for the link, albada.

Juan can you recall the test you saw and provide the link and was there any mention in the test you saw as to how the extent of underexposure affected the shadows ?

Thanks

pentaxuser

No idea where I read that...
But testing it isn't difficult.
Anyway, caring about PanF+ and pushing is good enough.

 

[BHuij]

I recently happened onto an exposed roll of FP4 (not FP4+) in my dad's attic with a bunch of his other film stocks. He hasn't shot film since he switched to digital in the early 2000s, although he's still an active photographer and we go out shooting together regularly. I was just plundering the several pro-packs of TMX 100 he had stashed away, as it was his go-to when shooting his RB67.

The exposed roll had an old note on it from his sister asking him to develop it for her.

I put it through some Rodinal and hung it up to dry. When we did some quick scans, a few things became clear:

1. The film had been shot through my dad's old Yashica Mat 124 (which I have now and still shoot a few times a year). It's the only 6x6 he ever owned.
2. The exposure happened in '84 or '85, thereabouts. 7-8 years before I was born.
3. Image quality was great. Not perfect, but very usable. I suppose there was a little fog, but shadow details were there and highlights were not blocked up.
4. It had some lovely photos of family members who have since passed away, including my dad's parents.

I've heard that latent images degrade with time, but this FP4 had few problems after nearly 40 years. It was definitely stored in the fridge or freezer for the majority of that time, but at least the last several years were in an attic (although admittedly a climate-controlled one that never gets terribly hot). It makes me smile to think that every childhood memory I can dredge up, this roll of film was probably sitting in the freezer in the garage, waiting for its day in the soup.

 

[RalphLambrecht]

Depends...
With PanF+, the notorious film when it comes to latent image (in)stability, the advice is to process ASAP, as in within a few days or so. Don't let it sit for weeks. A film like Kodak TMAX100 I think you can pretty safely store away exposed for a month or two and not notice the difference unless you do critical analysis on it. With color film, there's generally slightly less slack, but even that is mostly designed to work well if you take it on a really long holiday and only develop it after weeks. I never really encountered problems even with the occasional roll that was stuck in a camera somewhere for a couple of months.



The image just fades; overall loss of density, the shadows going first. Color film will shift.

I guess we all know those examples of the roll of film forgotten inside a camera and developed after 10/20/30 years exhibiting serious problems. But apart from this, I never experienced latent image stability as a problem.

It depends indeed. Speed and contrast will suffer over time. It depends on the film and also on storing conditions; the cooler the better. It also depends on the quality expect to get out of the negative; for the best quality develop as soon as possible; for low quality surveillance image, a few years may be acceptable.

 

[Huss]

Here's an example of Kodak Verichrome type 127 with the process-before date of November 1946. Developed in April 2022 in HC-110 dilution B at 7 degrees Celsius for 10 minutes. I did a strip test and aimed for lower density but the negatives are still pretty dense due to fog.

I would not recommend storing unprocessed film for more than 50 years.

lol, noted!
Great 'found' image. I assume you did not take it originally...

 

[cliveh]

I think this thread is giving Pan F unnecessary bad press, as many people under develop this film by following inaccurate charts and then blame it on the film. Pan F is a wonderful film and I have had no problem with this film when developed in D76 at 1:1 for 14 minutes at 20C.