Need help with reducing fog on expired film

[greg zinselmeier]

fresh film B+F is .10 or .11
expired film B+F is .18
developer is Pyro-cat Hd.

question1: How much more KBr is needed or can be used to reduce the fog? Hd has 1g per liter of stock solution.
question 2: if adding more KBr. besides reducung fog, what else should i expect? loss of film speed ( shadows detail)? or loss of high lights? would you recommend adding exposure? or adding time in developer?

any other suggestions are welcomed.

thank you in advance

 

[L Gebhardt]

I would not try to reduce minor fog on film. The fog affects the highlights and the shadow density equally. Just expose enough extra to get above the base fog and develop normally. Your negatives will require extra time for printing but the contrast will be normal. If you do try to reduce the fog you will probably affect the contrast and without testing your new developer, which it is since you are altering the chemistry, you won't know how much.

 

[PicklesFrog]

for expired film i usually just put in some Benzotriazole. If i cant get into the lab i just do 4x the amount of time it says on the dev chart.

 

[Rudeofus]

Among the most experienced folks with expired film&paper were a guy called John (sadly no longer active here) and another guy called David Lyga. Both shared their wisdom in a few threads here on photrio, such as this and this one.

 

[greg zinselmeier]

thanks! that was , "rude of us" David L. is quite right, loss of film speed, and adding more restrainer, and adding more development time is what is my results are proving out to be true.... thanks for the threads.


I keep forgetting to research post befor asking. I got what i needed.

 

[Bill Burk]

fresh film B+F is .10 or .11
expired film B+F is .18
developer is Pyro-cat Hd.

question1: How much more KBr is needed or can be used to reduce the fog? Hd has 1g per liter of stock solution.
question 2: if adding more KBr. besides reducung fog, what else should i expect? loss of film speed ( shadows detail)? or loss of high lights? would you recommend adding exposure? or adding time in developer?

any other suggestions are welcomed.

thank you in advance

It’s important to know if you plan to take fresh pictures on the old film or if you are developing old film to see what’s on it.

The strategy if you’re taking new pictures is to take pictures as if the film is slower. You have lots of options how you want to develop because the fresh image can rise above fog.

The strategy if it’s old exposures is to develop cold and fast to avoid fog ruining a fragile latent image.

 

[Patrick Robert James]

I kind of winced when you stated you were trying to reduce fog with Pyrocat... Staining developers are the worst for old film.

Best I've used over the years is Rodinal with a bit of BZT.

 

[Maris]

My 120 format Ilford Delta 3200 expired 2018 is running a B+F of 0.5. That looks very dark but the fog is even and I print right through it with no pictorial consequences that I can see. I've thought about using benzotriazole to suppress the fog but that reduces film speed and condemns me to a new series of Exposure Index calibrations that I'll need to immediately forget when a new batch number Delta 3200 comes along.

 

[greg zinselmeier]

Well, to answer my own questions. I’m going to do some tests with lowering film speeds and adding .02 bzt to working solutions, not stock, and keep doubling till I see a difference. I’m guessing this film will be 3 stops below and adding .04 bzt to working solution and adding carbonate to developer. And maybe even some time?? Just a guess,

 

[koraks]

and adding carbonate to developer

This will likely counter part of the effectiveness of the benzotriazole, especially in a staining developer. Raising pH will also raise the rate at which the developer oxidizes and puts down non-image dye stain all over the film.

I'm with @Patrick Robert James here - if you want to keep fog low on expired film, a staining developer is not the most obvious route to take. This is especially true if the negatives are intended to be printed with a UV-sensitive printing process, since the fog will come with a dye stain that can become hard to print through at some point. I've done some carbon transfers from expired film developed in Pyrocat lately and it was not fun printing some of those negatives.

 

[Rudeofus]

My 120 format Ilford Delta 3200 expired 2018 is running a B+F of 0.5. That looks very dark but the fog is even and I print right through it with no pictorial consequences that I can see. I've thought about using benzotriazole to suppress the fog but that reduces film speed and condemns me to a new series of Exposure Index calibrations that I'll need to immediately forget when a new batch number Delta 3200 comes along.

Of course you can print through fog, but remember: above D=0.3, every increase in density means an increase in image granularity. If your B+F already starts at D=0.5, then every area of your film will be affected. While this may be already annoying with ISO 100 film, a grain monster like Delta 3200 will certainly suffer a lot.

Hint: don't try to regain film speed in long expired stock. That film speed is gone. You can see expired film as "preexposed", which means whatever weak subject matter light would do to your film, heat and leaked light has already done. It's a bit like listening to someone whispering near a windy sea shore: an amplifier won't help you understand what has been said.

 

[greg zinselmeier]

A lot of great information, as always !! Thanks for everyone’s input. I appreciate your consideration to my questions.