Any data on duration of latent image by film brand/type?

[albireo]

I don't really use PanF 50 for some reason (I should), but every time I read about it on the internet someone will be recommending to process it as soon as possible after exposure because (if I understand correctly) the latent image tends to deteriorate pretty quickly.

I was wondering if this is typical of PanF only, or if it's a variable that strongly affects other film types too.

Is there data looking at several emulsions ranking their resilience to time-induced latent image degradation?

I am normally able to develop my film within a week of exposing, but I was wondering if, for some material, noticeable effects could already be appreciated when the exposure-development interval is stretched to (say) months rather than days/weeks.

 

[Mark J]

I'm not sure if there is a resource about this subject, but it does seem that Pan F+ stands out. I have used all of Ilford's current films, mainly in 120, and Pan F+ is the only one I had a problem with . From memory I have used Rollei RPX 25, Rollei IR 400 and older discontinued stocks like Konica IR and APX 25 also without problem.
Pan F+ is not too bad really, but it will have mostly faded away after 6 months, in a fridge, from my bitter experience.
Ilford say process within 3 months on their current datasheet. I'm not 100% confident in this ...
I recently ran off a roll of 35mm Pan F+ but it took me around 7 weeks to get in finished - however the images all looked strong and as exposed. This was stored in a fridge. So, I would suggest 'up to 2 months' as safe myself.

 

[relistan]

I’ve taken ten or more years to develop certain films and most films are good for at least 6-7 in my experience. I don’t recommend doing it on purpose. But sometimes you can build up a backlog…

ORWO UN54 six years:


Agfapan (real) APX-100 three years:


Agfapan APX-100 eight years:


Kodak Tri-X nine years:


Etc

 

[David R Williams]

I know this is off-topic, but relistan, I had to comment on these beautiful images. Lovely!

 

[relistan]

I know this is off-topic, but relistan, I had to comment on these beautiful images. Lovely!

Thank so much, I really appreciate you saying so!

 

[Photomultiplier]

slightly OT: i recognized the last image immediately! it is from my hometown

 

[relistan]

slightly OT: i recognized the last image immediately! it is from my hometown

Salzburg

 

[guangong]

For what it’s worth: several years ago the British Film Institute precessed film discovered from an early 1900s expedition found frozen in Antarctica and discovered images still intact. So storage conditions may play an important role. This is one of those questions with too many variables.
Also, many times folks on this site have developed film found in used cameras with images intact.

 

[Photomultiplier]

As there already is enough to worry about, i wouldn't worry about latent image keeping as well. Except for PanF where it is explicitly stated in the datasheet.

For all other films i have used, i have never seen any (detectable) deterioration. I recently processed Provia 100F sheet film shot in fall 2022 which was already expired then by over a year, but kept at below -23°C.
The exposed sheets were also kept in the freezer (i would bet money on it that the images would have been fine even when stored at room temperature)

Same for Velvia 50 and some rolls of Ektar 100. All were approx. 6months in storage before i processed them. The rolls, however, were "only" refrigerated.
One Ektar was even exposed in April 2022 and processed a few days ago, i just looked it up in my notes!
I also heard of some professional landscape photographers who kept exposed rolls for months before processing so that they forget what they photographed. (The photographers, not the films (hopefully) )

I personally would not worry even if they sat on the shelf for a year. But i make sure that unexposed film, especially expired one, is stored far below zero as long as possible. They usually expire during deep freeze, i always
buy them fresh before freezing them.

Fun Fact: i have a partially exposed 120 roll of Provia 400X in the camera closet since ~2009. Maybe i will expose the other frames at 200ISO and give it a spin in the processor. would be very interesting.


But regarding the original question: I have not seen any systematic controlled experimental results on latent image keeping. The time-frames of interest however, would be short enough to conduct such tests.
Maybe multiple test target shots under carefully controlled conditions on 135 over a year? I suspect the inaccuracies of the setup (shutter, aperture, exposure metering) to be larger than latent image deterioration, however.

 

[albireo]

Thank you everyone. Sounds like 'time to development' is in general nothing to worry about then.

Yet, I remain curious on what exactly makes PanF so different. If someone knows and would be willing to share that would be great.

 

[abruzzi]

I have a few sheets of Adox CMS20 that were exposed maybe 3-4 years ago. I've been holding off developing them because I want to mix up the Adox developer and develop enough sheets to exhaust the developer in one go, without trying to keep it. I'm hoping I can get that done in the next year or so, so I'll compare the older shots with the newer shots when I do.

 

[MattKing]

Long are gone the days when you picked up the camera and shoot only what it counted the most, holidays, trips etc... and you finished the roll maybe one year later, without any significant degradation of the image.

Or more accurately, the images were degraded approximately the same amount as the rolls you had developed one year ago, two ears ago, three years ago , ....
My Dad was customer service manager at a Kodak Canada Kodachrome processing lab. One day while we were out for a walk a neighbour came up to him and complained that Kodak had "ruined" his film.
Dad took the slides into the lab, where the quality control people noted the damage, but pointed out that the roll appeared to include photos from more than one year, including at least two vacations that involved flying to and from Western Canada to Hawaii, including any X-ray exposure that 1970s flying might have entailed!
Dad arranged to give the neighbour a free replacement film anyways, along with some advice.

 

[Alan Edward Klein]

As there already is enough to worry about, i wouldn't worry about latent image keeping as well. Except for PanF where it is explicitly stated in the datasheet.

For all other films i have used, i have never seen any (detectable) deterioration. I recently processed Provia 100F sheet film shot in fall 2022 which was already expired then by over a year, but kept at below -23°C.
The exposed sheets were also kept in the freezer (i would bet money on it that the images would have been fine even when stored at room temperature)

Same for Velvia 50 and some rolls of Ektar 100. All were approx. 6months in storage before i processed them. The rolls, however, were "only" refrigerated.
One Ektar was even exposed in April 2022 and processed a few days ago, i just looked it up in my notes!
I also heard of some professional landscape photographers who kept exposed rolls for months before processing so that they forget what they photographed. (The photographers, not the films (hopefully) )

I personally would not worry even if they sat on the shelf for a year. But i make sure that unexposed film, especially expired one, is stored far below zero as long as possible. They usually expire during deep freeze, i always
buy them fresh before freezing them.

Fun Fact: i have a partially exposed 120 roll of Provia 400X in the camera closet since ~2009. Maybe i will expose the other frames at 200ISO and give it a spin in the processor. would be very interesting.


But regarding the original question: I have not seen any systematic controlled experimental results on latent image keeping. The time-frames of interest however, would be short enough to conduct such tests.
Maybe multiple test target shots under carefully controlled conditions on 135 over a year? I suspect the inaccuracies of the setup (shutter, aperture, exposure metering) to be larger than latent image deterioration, however.

My problem is I often keep exposed and unexposed film in the trunk of my car through seasons of warmth and cold.

 

[Alex Benjamin]

Thread makes me wonder if they finished processing the 2,500 rolls of undeveloped film Winogrand left when he died in 1984...

 

[MattKing]

Thread makes me wonder if they finished processing the 2,500 rolls of undeveloped film Winogrand left when he died in 1984...

Yep - Sasha Waters Freyer, the producer, director and editor of the excellent "Garry Winogrand: All Things Are Photographable" documentary talked about that at the "talk to the director" session after a 2018? screening I attended of the movie in Vancouver, BC.
A significant number of the photographs shown in that movie came from those negatives - because the movie also dealt with his life near the end.

 

[Alex Benjamin]

Yep - Sasha Waters Freyer, the producer, director and editor of the excellent "Garry Winogrand: All Things Are Photographable" documentary talked about that at the "talk to the director" session after a 2018? screening I attended of the movie in Vancouver, BC.
A significant number of the photographs shown in that movie came from those negatives - because the movie also dealt with his life near the end.

Thanks for the update, Matt!

 

[Doremus Scudder]

My problem is I often keep exposed and unexposed film in the trunk of my car through seasons of warmth and cold.

A cheap cooler keeps the temperature spikes from happening. Still, it's not good practice to leave your film in a too-hot environment for long periods of time, so, to paraphrase Nike, "Just don't do it."

 

[bluechromis]

I have read that IR sensitive film tends to have a less stable latent image.

 

[bluechromis]

I know this is off-topic, but relistan, I had to comment on these beautiful images. Lovely!

Agee!

 

[MattKing]

I know this is off-topic, but relistan, I had to comment on these beautiful images. Lovely!

This sort of comment is never truly off-topic.

 

[Slixtiesix]

Yes it is true for PanF+. Very good film otherwise, but the latency is not a myth. I had one roll in my camera for more than a year. The last pictures (taken only a few days before processing) were all fine. The first ones (taken 8 to 12 months before) were all faded to a degree that correlated with the duration they had been latent on the film.
On the other hand, I processed several rolls of FP4+ more than two years after exposure without any problems.

 

[Agulliver]

I've seen several people who use Ilford PanF + a lot more than I do, state that the latent image really starts to deteriorate by three months. Consensus also seem to be a few weeks to at least a month isn't a problem.

I think every other film, certainly that I have ever used, the latent image lasts for years. I've developed films found in cameras inherited from deceased relatives and found in bought cameras which were exposed 30-60 years before I developed them. Even C41 colour film 45 years old will yield some sort of images. B&W often will yield excellent images. About three years ago just before the pandemic really hit, I bought a new couch and in disassembling the old one for collection I found a roll of Tri-X in the recliner mechanism that I'd shot over a decade previously. The results were perfect.

Back in the day, many casual snap shooters would shoot a partial roll of film on their annual summer holiday and finish it the following year without thinking twice.