Patchy negatives

[Bbernardez]

I’m starting to develop B&W film at home and I exposed a few test rolls knowing I would screw something up so I can correct it before developing anything I’ve put effort into. In this case it’s Ilford FP4, pre washed, developed in rodinal, agitated for 10 seconds every minute (it came out a bit foamy but not too much I think), ilfostop stop bath and ilford rapid fixer. The problem is I don’t know what happened here!

All the images look like this and I don’t even know what it is or how to call it so I apologise if it has already been addressed.

 

[NB23]

Looks to me like film exposed to excess heat.

 

[Doremus Scudder]

Backing-paper problems. There are lots of threads on this; do a quick search. Film may have been stored in too-humid conditions, etc. and the backing paper damaged the film surface.

Doremus

 

[foc]

Backing-paper problems. There are lots of threads on this; do a quick search. Film may have been stored in too-humid conditions, etc. and the backing paper damaged the film surface.

Doremus

+1

 

[Bbernardez]

Looks to me like film exposed to excess heat.

Thank you for you reply
Is that during development or being improperly stored? It can get really hot here in summer

 

[Bbernardez]

Backing-paper problems. There are lots of threads on this; do a quick search. Film may have been stored in too-humid conditions, etc. and the backing paper damaged the film surface.

Doremus

I didn’t know where to start, thank you!

 

[Dwayne Martin]

Has the film been through air port security? Not sure what that sort of damage actually looks like but it is another peril film could face.
Rodenol is famous for keeping very well on the shelf so the dev should be ok. I used to worry my film would get over heated while being shipped but to date it hasn’t happened to me…
Maybe try a fresh roll from another source and keep the rest of your procedure exactly the same to rule out the film.
Also not sure what caused the foam but when agitating just tip it back and forth medium speed don’t shake it.

 

[Bbernardez]

Has the film been through air port security? Not sure what that sort of damage actually looks like but it is another peril film could face.
Rodenol is famous for keeping very well on the shelf so the dev should be ok. I used to worry my film would get over heated while being shipped but to date it hasn’t happened to me…
Maybe try a fresh roll from another source and keep the rest of your procedure exactly the same to rule out the film.
Also not sure what caused the foam but when agitating just tip it back and forth medium speed don’t shake it.

It hasn’t been through airport security, at least I don’t think so. I tried a couple things, I used a fresh roll of film as you suggested and it came out perfect, I then also developed a 35mm canister I had kept in the same place for the same amount of time and I didn’t find any problem either… looks like it was just this particular roll that was damaged.

As for the foam, I think that the tank wasn’t properly cleaned and there was some wetting agent residue which caused the foaming, I’m not sure.

thank you for your reply

 

[koraks]

Not sure what that sort of damage actually looks like

Not like this. Radiation damage usually looks like soft-edged flame patterns, horizontal, diagonal or vertical bands or (a bit less likely) overall density. Radiation from an airport scanner will virtually never* give the kind of splotchy pattern we see here.
*(The exception is if the film is partially shielded with a material that has this density pattern to xrays - quite unlikely to happen).

But fortunately the cause is crystal clear and has already been mentioned a few times - backing paper problems. Usually due to improper storage, sometimes in combination with poor material choices by the manufacturer.

 

[AgX]

It is called mottling. A backing paper/emulsion interaction.

In the long past described by the industry as result of uncovered storage long time at most humid circumstances.

However recently a lot of these artefacts appear. One could argue that it is a feedback-loop internet phenomenon, But there a reports by people stating that they treatedd their films correctly, moreover not different as all years before.
But meanwhikle at least Harman (Ilford) have admitted that they got respective claims and indicated that indeed this is something new.


Basically a paper issue as such existed already fifteen years ago and I myself worked on alternatives.