Benzotriazole for expired film?

bluechromis

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I have a roll of unexposed Kodak Verichrome Pan film from 1980 that I would like to shoot and develop. I am thinking of using HC-110. Some people recommend adding a bit of benzotriazole to the developer to mitigate fog with expired film. Is this a good idea? If so, how much should I add?
 

koraks

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Personally, I'd just develop as is. There will be fog, but so what? Print/scan through it.
If you add a restrainer, it's a balancing act. Add too little and you still have fog. Add too much, and image density is lost (i.e. shadows don't get developed).
 

Alan Johnson

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I have some old TMY and also reached the conclusion it is better for shadow detail to extend development and print through the fog:

1% Benzotriazole + Expired Film

Attachment shows effect of adding 1% Benzotriazole solution to 20 year old T-Max 400 all exposed at EI=100 and developed in PaRodinal 1:50 8min 20C. What is a good combination of ml/L 1% Benzotriazole and increase in development time? 10ml/L and 30% increase? Thanks.
www.photrio.com
 

Huub

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Overexposing will also help to get better results, especially with faster films. Count a stop for every 10 years as a rough approximation.
 

Don_ih

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Benzo will help with fog. The problem, though, is it completely changes the development time. Unless you've done it with that film, that developer, and that amount of benzo before, you won't have any idea how long to develop the film. Plus, if you extend development too much because you don't know how long to use it for, the fog will build up.

HC110 is a good choice. Rodinal would also be a good choice (1:25 - not stand). If you want lower fog, don't use an MQ developer.

If you're willing to unroll the film before you expose it and cut off the first exposure (retape the end), you can expose that single exposure in a camera, cut it in half, then you'd have two strips you can test for proper development.
 

loccdor

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Huub said:
Overexposing will also help to get better results, especially with faster films. Count a stop for every 10 years as a rough approximation.
Click to expand...

Seconded. Although it is a slow black and white. So I would try exposing it at 25 ISO as a first guess. Better if you can buy expired film in lots rather than singles.
 

Don_ih

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Yeah, it's from 1980. If it was stored at cool-normal room temperature, it might not have much fog.
I assumed it was 120. I don't think they sold Verichrome in 135?
The biggest problem might come from the paper.
 

loccdor

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Don_ih said:
The biggest problem might come from the paper.
Click to expand...

Agreed. OP, Don is referring to the backing paper markings, visible as mottling or number and arrow imprints, that can happen with 120 film. I don't believe there are any development tricks to that particular issue.
 

Alan9940

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I don't use anti-fog often, but I've had very good results with Rodinal 1:50 + 10 drops (about 1/2 ml) of 1% Benzotriazole solution. You might want to add about 10% to your development time and you may still have a bit of fog, but it will be easily printed through.
 

Don_ih

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On a side note, I added benzo and hydroquinone when I made some parodinal, once. It worked very well. However, I don't think you've ever smelled anything worse - a bit like highly concentrated cat urine being used to pickle fish. I couldn't use the whole batch.
 
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bluechromis

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Thanks Alan.
 
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bluechromis

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Thanks.
 
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bluechromis

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Don_ih said:
Yeah, it's from 1980. If it was stored at cool-normal room temperature, it might not have much fog.
I assumed it was 120. I don't think they sold Verichrome in 135?
The biggest problem might come from the paper.
Click to expand...

It is actually 127 size film.
 

MattKing

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Don_ih said:
However, I don't think you've ever smelled anything worse - a bit like highly concentrated cat urine being used to pickle fish.
Click to expand...

And how did you become aware of this comparable?
 

lamerko

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Assuming that bleach destroys the latent image (and there are such claims by PE), what would happen if the film was pre-washed with rehal bleach (no developer and fixer, no light exposure)? In theory, wouldn't this "reset" the film without disturbing the crystal structure?
 

koraks

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lamerko said:
Assuming that bleach destroys the latent image (and there are such claims by PE)
Click to expand...

It's the principle that SLIMT is based on. https://www.photrio.com/forum/threads/slimt-and-why-you-should-be-using-it.64135/
Allegedly, the bleaching is non-linear; i.e. areas that received more exposure bleach more readily.

It's a contentious topic though and I'll be probably sorry to have brought it up. I've tried it on occasion, but I admit my testing was (1) not particularly rigorous and (2) I don't think I kept the results. So I can't/won't say that it worked as advertized - only that the ferricyanide bleach certainly did affect the latent image.

lamerko said:
In theory, wouldn't this "reset" the film without disturbing the crystal structure?
Click to expand...

I think it would sort of reset it, but there would have been a disturbance of sorts due to the exposure (creating developable centers on the silver halide particles) which is then reverted back to unexposed silver halide. To what extent it's possible to bleach back the latent image entirely to a "virgin-equivalent" status, I can't say.
 

lamerko

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Oh, OK. I decided to test this theory. To that end, I've prepared two movies tonight that I know are extremely affected by base fog. One is an old ORWO NP27, expired perhaps sometime around 1987. It is a black and white panchromatic film with a nominal speed of 400 ASA. The second film is an old expired Kodak Eastman EXR 500T from the early 90's. This is a color cinema film using the ECN-2 process. You could say that these two films are contemporaries.
Since the EXR 500T has a remjet antihalation coating, I decided to remove it beforehand. I also sacrificed half a liter of isopropyl alcohol - dipping the films in pure alcohol makes them dry instantly...
 

koraks

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Ah, that's interesting! I've no idea how this process might affect age-related fog. You'd expect it would help lift it somewhat - then again....
koraks said:
To what extent it's possible to bleach back the latent image entirely to a "virgin-equivalent" status, I can't say.
Click to expand...
 

Romanko

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bluechromis said:
Is this a good idea?
Click to expand...
I would not do it. Increase exposure, bracket and develop as normal in dilution B. The development times are in the technical data sheet which is still available online. If stored properly this Verichrome Pan would be as good as new.
 
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bluechromis

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I shot the expired Verichrome Pan 127 film in a Kodak Brownie Holiday Flash camera I borrowed. I developed it in HC-110 dilution H for 22 mins. One inversion/minute in a Patterson tank. It could of used a bit more time, but I was happy to get something out of it.
 
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