More Fomapan 400 120 defects

[Harry Callahan]

Sigh, i said right from the start that this desensitization does apply to Foma 200. I did not claim it to apply for Foma 400. Also i did not claim it to be the reasons for the Foma 400 problems in this thread here - all i said was that with Foma 200 apparently mechanical strain can lead to desensitization.
I am aware that "strain" does not equal "pressure", though i looked in a dictionary where about the last entry did translate "strain" by "pressure" - so far fetched they also could be talking about pressure, but the paper is vague on that.
But the paper makes it seem like it is the T-grain which does react by fewer density when strain is applied to the film.
I am aware that Foma 200 is the only film having T-grain.
I don`t consider emulsion cracks "reduced density due to mechanical pressure" and never said so.

If the reason for Foma 200 having these problems was emulsion cracks, it would be easier to put this in the paper - and advice people to only use medium format cameras where the film does not make tight turns, like in a Hasselblad magazine for example. If the reason was emulsion cracks this film should be unproblematic in an old folder for example - but as i read from your statement it is not related to film travel through the camera.

As we did not talk about pressure on emulsion in a thread about Foma 200, i put my finding in a thread where we were talking about pressure on emulsion - like this thread here.

I don`t have empirical evidence, i probably couldn`t provide a waterproof explanation even if the effect was real - i wanted to add my finding to a thread where we were talking about the possibility of mechanical pressure to maybe add something useful.

But you keep on interpreting that
- i am talking about Foma 400
-i believe this to be the reason for the problems of 400 discussed in this thread
-i`m trying to conjure credibility for my theory
-i consider strain to be the same a pressure
-i consider emulsion cracks to resemble reduced density
-and whatever

- and that`s why i feel like talking in a foreign language for example. People interpret a whole bunch of stuff into a statement of mine - including a lot of things i never said. And if i do state for days, over and over again, that i am talking about enlarging only - several believe that i am talking about shooting and answer related to shooting pictures.

 

[John Wiegerink]

Sigh, i said right from the start that this desensitization does apply to Foma 200. I did not claim it to apply for Foma 400. Also i did not claim it to be the reasons for the Foma 400 problems in this thread here - all i said was that with Foma 200 apparently mechanical strain can lead to desensitization.
I am aware that "strain" does not equal "pressure", though i looked in a dictionary where about the last entry did translate "strain" by "pressure" - so far fetched they also could be talking about pressure, but the paper is vague on that.
But the paper makes it seem like it is the T-grain which does react by fewer density when strain is applied to the film.
I am aware that Foma 200 is the only film having T-grain.
I don`t consider emulsion cracks "reduced density due to mechanical pressure" and never said so.

If the reason for Foma 200 having these problems was emulsion cracks, it would be easier to put this in the paper - and advice people to only use medium format cameras where the film does not make tight turns, like in a Hasselblad magazine for example. If the reason was emulsion cracks this film should be unproblematic in an old folder for example - but as i read from your statement it is not related to film travel through the camera.

As we did not talk about pressure on emulsion in a thread about Foma 200, i put my finding in a thread where we were talking about pressure on emulsion - like this thread here.

I don`t have empirical evidence, i probably couldn`t provide a waterproof explanation even if the effect was real - i wanted to add my finding to a thread where we were talking about the possibility of mechanical pressure to maybe add something useful.

But you keep on interpreting that
- i am talking about Foma 400
-i believe this to be the reason for the problems of 400 discussed in this thread
-i`m trying to conjure credibility for my theory
-i consider strain to be the same a pressure
-i consider emulsion cracks to resemble reduced density
-and whatever

- and that`s why i feel like talking in a foreign language for example. People interpret a whole bunch of stuff into a statement of mine - including a lot of things i never said. And if i do state for days, over and over again, that i am talking about enlarging only - several believe that i am talking about shooting and answer related to shooting pictures.

Harry,
I don't seem to have much of a problem with either Foma 100 or 400, but have relegated Foma 200 just for testing repair cameras out just in hopes that one of those "just repaired cameras can eliminate those tiny little emulsion cracks. So far none have and even my older straight run folder can't seem to stop those little gremlin cracks from showing up. It must just be my luck or maybe the way I hold my mouth when I trip the shutter or wind the film on.

 

[Harry Callahan]

I see, thank you for the answer.

 

[Thomas Bertilsson]

Waking up an old thread here, just reporting that I had a batch of Fomapan 400 in 120 format that had the same problem it has had in the past with an imprint of the backing paper on the film. I had 20 rolls, out of which I used 11. Batch number 011756 5. Expiration date November 2025.
- Rolls of other brands developed alongside were fine (Kentmere 400, Ilford HP5+)
- Three different developers used (D76 1+1, Paterson FX-39 1+9, PMK-Pyro) makes no difference on the outcome
- Presoak and no presoak makes no difference on the outcome

My advice would simply be to only use this film from a batch you for sure have tested, and within a short time of testing it. The problem seems to get worse the longer the film sits unused.
It has ruined dozens of rolls for me over the last years. I absolutely love how the film looks once processed and printed, but the extra step of having to test the 120 film each time is very tiring. The attached picture is one example from a contact sheet, there are those that are a little bit better, and those that are a bit worse.

 

[koraks]

Oh yeah, that's classic. You're right that the risk & impact get bigger the older the film is, with storage conditions being an important moderating variable.