Fomapan Classic 100, strange marks on film

[fdonadio]

I've been using Fomapan 100 for some time now in 4x5" and I noticed these strange marks all over the photos from my last trip. I have to go back to my older stuff and see if there are marks like these, but I think I would remember if I had these before. Looks like some very small cracks... or maybe something like fungus.

I used a stop bath and, maybe, that's the problem, although I always used a stop bath. There are pinholes in the emulsion and I will try processing some sheets without a stop bath to see if they go away.

Look at this crop from above the stage:

The marks are stronger in some pictures and I can't see them with a loupe.

I looked at some photos I took with Ilford HP5+ and they don't show the problem.

Please, help me understand what's wrong.


Cheers,
Flavio

 

[georgegrosu]

Flavio, your problem looks very much like the defect presented here.
(there was a url link here which no longer exists)
When look the defects on the film emulsion in reflected light.
You see the defect on the emulsion or in the emulsion?

George

 

[fdonadio]

Flavio, your problem looks very much like the defect presented here.
(there was a url link here which no longer exists)
When look the defects on the film emulsion in reflected light.
You see the defect on the emulsion or in the emulsion?

Thanks a lot for the pointer. I was really worried that no one had said anything yet!

I'll take a better look tonight and read that whole thread.

 

[fdonadio]

I've read that whole thread and, from what I understand, the problem was never identified.

My marks look pretty much like those, but being on sheet film, they are pretty hard to see. My loupe is a 7x and isn't enough to have a clear image of the marks.

Looking at the film with a light source at an angle, I can't see any texture resembling the marks on the film surface. On the emulsion side, I can see the characteristic grainy texture. The base side is smooth and shiny, as it should.

Previous photos with film from the same box don't show the marks. This would indicate a problem with my processing technique, but I didn't change anything, except for the fixer: I used to use Kodak fixer (the only one they sell nowadays) and, since I ran out, started using homebrewed F-24.

I use a MOD54 in a Paterson tank and, when the ambient temperature is over 22°C, an ice bath is used to cool the chemistry to that temperature. I wash with deionized water (Ilford method) and, on that day, it was around 24°C. Some Photo-Flo and then hang the film to dry. The darkroom itself was around 26°C that night and I never use any kind of dryer.

Like said before, I used an acetic acid stop, which I intend to replace with a water wash to prevent pinholes. I have always used an acetic acid stop and can confirm there are pinholes in my older material (same box of film). The pinholes are bigger than the marks and much easier to see, even without a loupe, in the dark areas.

I am thinking about using a hardening fixer, since Foma emulsions are so easy to scratch.


Cheers,
Flavio

 

[georgegrosu]

Sorry for my English.
From what I understand, you did not see neither on emulsion nor support any defects?
I can conclude that the problem is inside the emulsion layer?

Problem of defects appearing on film is complicated by the fact that it can be seen only after processing the film.
That's why appears probably a tendency to suspect first processing.
It is not always so.

George

 

[Gerald C Koch]

Pinholes are only a problem WITH acid stop baths AND carbonate based developers. What developer is being used? If it's not a carbonate based one then the problem lies elsewhere, perhaps a defect in manufacture. In addition pinholes will appear as black on the print and not as white spots as in the two examples. This again points to some other cause. Perhaps dust or sediment in the developer.

 

[Craig75]

it looks like the emulsion is too soft and been physically damaged somehow and somewhere in the processing.

try and pre harden it before developing it to protect it?

 

[georgegrosu]

The general image shows several defects.
In the crop, it seemed to me that there are serious faults “Y”, or the stars.
White spots appear I have not discussed.
White spots may came from developer impurities(Gerald C Koch said)
or dust from cutting and perforation of film.

fdonadio said:
"Looking at the film with a light source at an angle, I can't see any texture resembling the marks on the film surface. On the emulsion side, I can see the characteristic grainy texture. The base side is smooth and shiny, as it should."

George

 

[Doremus Scudder]

I had a similar problem years ago with BPF-200 sheet film. The defect appeared on older film only, and on the base side. I seemed to me that the base coating was degrading. I don't think it was a processing error; I'd processed many, many sheets of the same film before in exactly the same way. The problem prompted me to quit using the film. BPF-200 is no longer available, but maybe your problem is similar...

Good luck,

Doremus

 

[fdonadio]

Thanks everyone for the help.

@Gerald C Koch : developer is homebrewed D-76, prepared according to Kodak's published formula and filtered with a paper coffee filter. One of the pinholes is visible on the photo, to the right of the cropped area. White spots are dust on the scanner. These are not what I'm really worried now.

@georgegrosu : I can only conclude the marks are inside the emulsion. A better loupe or more powerful optical equipment would help!

@Craig75 : Yeah, Foma is known for their soft emulsions. I am inclined to try hardening it. I just don't know if I should pre-harden or use a hardening fixer. If pre-hardening, what hardener should I use?

@Doremus Scudder : I still have half this box and a sealed 50-sheet one! At least there's enough material for tests!


Cheers,
Flavio

 

[Craig75]

I use tetenal hardener as a pre hardener when im messing around at high temperatures and that allowed me to reticulate some very ancient 16mm kodak safety film without the emulsion sliding off at over 50 degrees centigrade so im assuming a pre harden of your forma should get it through the development process without emulsion swelling and cracking (if that is the problem...)

I think tetenals hardener is just a chrome alum hardener so you could make it yourself if tetenals isnt available in your area. I could never quite understand which fixers you could add tetenals to when i had issues with liquid emulsion coating - you cant use it with ilford rapid fix, you can use it with ilford hypam, but i was never clear if you could use it with tetenal rapid fix, you cant use it with a powder fixer etc etc. So if you dont want to use it as a pre hardener before the developer then it might be best using it as a separate bath before your fixer of choice then washing then fixing.

 

[fdonadio]

Thanks, @Craig75 ! I happen to have chrome alum and I will search the archives for a hardener recipe. @Photo Engineer must have published one!

 

[Gerald C Koch]

With D-76 you will not see any damage caused by gas generation, ie the typical pinholes. Have you contacted Foma as it may be a manufacturing defect?

Back when films were softer I used a lot of chrome alum. Use Ilford IH-6 a 3% solution. The solution does not keep and should be made of fresh. You can use it before the fixing step.

 

[fdonadio]

Have you contacted Foma as it may be a manufacturing defect?

I didn't. I bought this film more than a year ago and I thought I would ask here first. I'll be sending them an e-mail.

Back when films were softer I used a lot of chrome alum. Use a 3% solution. The solution does not keep and should be made of fresh. You can use it before the fixing step.

Is it any better than using a hardening fixer?

 

[Trask]

I use tetenal hardener as a pre hardener when im messing around at high temperatures and that allowed me to reticulate some very ancient 16mm kodak safety film without the emulsion sliding off at over 50 degrees centigrade so im assuming a pre harden of your forma should get it through the development process without emulsion swelling and cracking (if that is the problem...)

Interesting -- I've heard of, and used long ago in the past, hardening fixer, but I'd not heard of hardening the film prior to the initial developing step. I would have imagined that the hardening would inhibit or preclude development, so intriguing to hear otherwise.

 

[Craig75]

hardeners dont work will all fixers (as i understand) so unless you know all the ins and out of it all (which i dont!) it will be safer to use it as a separate bath (and remember to wash film after hardening before any other stage) to keep all the random variables out of the equation. In the first instance it might be worth using it before the developer and if that "y" effect is still appearing then at least you know 100% the emulsion is damaged / brittle in the box which would sadly confirm doremus's findings. If the film survives the whole process then you can try moving the hardener bath before the fixer so to eliminate any possible interferance of the hardener with the developer and allow you to shoot with confidence that your workflow is not being disturbed by the hardener.

is how i would do it - but i'm not very sciencey at all - and what I have written could all be total nonsense - but nothing ventured,nothing gained and every failure is a learning experience is how i console myself with my many failures

 

[fdonadio]

@Craig75,

What you said makes very good sense. I am gonna try and see what I come up with.

I'm gonna have some friends at home this weekend and will use them as subjects for my tests.

 

[Craig75]

Interesting -- I've heard of, and used long ago in the past, hardening fixer, but I'd not heard of hardening the film prior to the initial developing step. I would have imagined that the hardening would inhibit or preclude development, so intriguing to hear otherwise.

I tried doing some of Henry's experiments at high temperatures in his "controls in black and white photography book" - he used a pre hardener before a developer at 40 degrees to stop the emulsion coming off and it worked. I dont know how much interference (if any) the hardener causes in the development but I got a nice photo out of it. The only other time i did it before developer was to toughen some very old looking 16mm film to keep the emulsion on the film before reticulating it - that worked but with film that old (im guessing at least 40-50 years) then who knows whats going on with it just developing it normally let alone with a pre hardener.

In short, you def get a negative (and i got what i thought was a nice negative too even if by luck rather than skill) but how much its interfering in development ,if at all, i dont know.

 

[Gerald C Koch]

I didn't. I bought this film more than a year ago and I thought I would ask here first. I'll be sending them an e-mail.



Is it any better than using a hardening fixer?

Chrome alum loses its hardening capability in the presence of sulfite or thiosulfate. While a chrome alum fixer may work for a day or so it rapidly loses its effectiveness. Best to use chrome alum as a one-shot.

You can also use a conventional acid hardening fixer like Kodak F-5 which uses potassium alum. However potassium alum is less effective than chrome alum.

 

[fdonadio]

You can also use a conventional acid hardening fixer like Kodak F-5 which uses potassium alum. However potassium alum is less effective than chrome alum.

Thanks again, Gerald!

I'm trying it after development and, if the marks don't go away, before.

Last questions: one minute in the hardener is enough? Three or four water changes should be good between hardener and fixer? Should I extend fixing time?

 

[Gerald C Koch]

Thanks again, Gerald!

I'm trying it after development and, if the marks don't go away, before.

Last questions: one minute in the hardener is enough? Three or four water changes should be good between hardener and fixer? Should I extend fixing time?

lford recommends using 3 minutes in the chrome alum bath. Gelatin hardeners work by creating cross linkages in the gelatin. If you are using a very alkaline developer then use a couple of rinses between the developer and the hardening bath. The hardener will not harm the fixing bath. So no need for a rinse there.

 

[fdonadio]

Thanks again, @Gerald C Koch! I feel 100% confident now.

I hope it works.

 

[Gerald C Koch]

I have been asked in a PM to clarify the keeping properties of chrome alum solutions. Unused chrome alum solutions keep indefinitely. However, once used a solution rapidly loses its hardening capabilities.

 

[fdonadio]

You can also use a conventional acid hardening fixer like Kodak F-5 which uses potassium alum. However potassium alum is less effective than chrome alum

I thought I was going to experiment with this tonight, but there's no Chrome Alum in my stash. Only Potassium Alum and Thiourea.

Any ideas?

 

[Craig75]

you can use potassium alum as a hardener too.