Film Fogging Mystery...

[Nikanon]

Ok everyone, I need some help troubleshooting a fogging issue that is getting out of hand.

I am developing with FG7 Concentrate (obviously somewhat old, but only recently opened) in a large plastic bottle, about a gallon or so. The film in question is Tri-x 400 (either from kodak or Arista 400 Premium).

I first noticed the problem when I used a 5 roll tank, developing at 68F for 12 minutes, 1 +15.

SOME of the 5 rolls, not all, had some slight fogging that was maybe 0.15 higher than the normal FB+F

I thought maybe this was a manufacturer issue, or that my rolls had been fogged from heat, etc because they were old (nothing is older than 2 years and has never been exposed to direct heat for a prolonged period of time) even though that was unlikely.

I have gotten the issue randomly when using films in 2 reel tanks and 5 reels where sometimes all of the film is fogged and sometimes only one, and sometimes none.

I just developed 6 rolls in 3 separate 2 reel tanks for 12 minutes at 68F 1+ 15, I agitate for the first 30 seconds and then for 5 seconds every 30 seconds thereafter.

ALL SIX ROLLS WERE FOGGED, SIGNIFICANTLY. Possibly 0.20 or higher above normal FB + F. All of the tones are normal, the film does not appear over developed.

What the hell is happening? Could it be that only some films are somehow fogged? Could it be the developer? I don't have any consistent results that say it is either of these. I have developed 125 PX without any fog in this developer, and have developed some Tri-x without issue before... Any clues?

 

[Nikanon]

Another feature of the fog is that it does not continue all the way across the film. At the VERY edges of the film of the sprocket holes I can see unfogged film base. This makes me think it could possibly be due to the agitation, since the film is completely immersed in the developer, only the edges of the film covered by the reels could possibly be safe from agitation, but would it cause this much fog? The high values are however normal, so it could not be over agitation..

 

[Rick A]

Changing bag or dark room for loading he reels? Which ever, non light tight some how?

 

[Nikanon]

I just cut a piece of the film off ( which is washing now) and used my densitometer to measure the film base. The film base plus fog reading was 0.52, which is VERY high. I read about a 0.30 as normal FB + F on my other rolls of Tri-x.

 

[Nikanon]

Changing bag or dark room for loading he reels? Which ever, non light tight some how?

I ruled that out when I had fog on only some of the rolls in a single tank as they were all loaded in the same space, which is a light proof changing closet built specifically for film loading.

 

[erikg]

I'm inclined to agree with what Rick is suggesting, I would look at the loading situation. The variation could be due to the amount of time a loaded reel was waiting for the others, if the room or bag wasn't totally light tight, the edges may have been protected by the reel. All speculation at this point, but that's where I would start.

 

[Nikanon]

I'm inclined to agree with what Rick is suggesting, I would look at the loading situation. The variation could be due to the amount of time a loaded reel was waiting for the others, if the room or bag wasn't totally light tight, the edges may have been protected by the reel. All speculation at this point, but that's where I would start.

Hmm, that is possible I suppose, although after 5 minutes in the darkened room I still cannot see my hand in front of my face after my eyes adjusted. I will make sure to eliminate this. Annoying that I now have to work one roll at a time so as not to ruin a large batch at once..

The negatives all look normal other than the 0.50 FB + F and im sure will all be printable and just fine, although its VERY annoying to have that added time, and I know some of that fog is going to ruin some of my acutance...

 

[mfohl]

I'm assuming you are using plastic Paterson tanks. Are you sure that you are closing your tanks properly, and alternately, are there any cracks in the lids of the tanks? How are you agitating: inversion or using the twirler thingy? Make sure you invert.

 

[erikg]

Well maybe it's not the loading area. After 5 minutes, certainly after 10 you would see any light source strong enough to fog. Variation in the film stock perhaps?

 

[MattKing]

If you are using Paterson Super System 4 Developing tanks, you will note that they have red rings on the top of the main section.

Those rings are affixed by some sort of adhesive - I have one tank where the adhesive gave way. That allowed the light-tight lid to come loose unexpectedly.

Once re-glued, that tank was fine.

 

[Nikanon]

I'm assuming you are using plastic Paterson tanks. Are you sure that you are closing your tanks properly, and alternately, are there any cracks in the lids of the tanks? How are you agitating: inversion or using the twirler thingy? Make sure you invert.

I ruled this out too by using 3 separate tanks, I have been using them for years in the proper manner, the tube is not inverted and the tops are properly closed. I agitate by turning the tanks and inverting them. No cracks anywhere.

 

[Nikanon]

Well maybe it's not the loading area. After 5 minutes, certainly after 10 you would see any light source strong enough to fog. Variation in the film stock perhaps?

I ruled this out by using different stocks of the same Arista Premium 400 film (tri-x) and even if that were improperly loaded and causing fog by freestyle, I also used Tri-x rolls straight from Kodak.

 

[Nikanon]

If you are using Paterson Super System 4 Developing tanks, you will note that they have red rings on the top of the main section.

Those rings are affixed by some sort of adhesive - I have one tank where the adhesive gave way. That allowed the light-tight lid to come loose unexpectedly.

Once re-glued, that tank was fine.

All red rings are securely in place.

Also, a friend developed his Tri-x 400 in the same developer with the same tanks at the same time/ temp/ agitation/ dilution, etc. He had no trace of this fogging at all. For me that rules out the developer.

 

[erikg]

I ruled this out by using different stocks of the same Arista Premium 400 film (tri-x) and even if that were improperly loaded and causing fog by freestyle, I also used Tri-x rolls straight from Kodak.

So you are seeing fog randomly across all of these films? Same camera always?

 

[Nikanon]

So you are seeing fog randomly across all of these films? Same camera always?

It is almost like a stain, it does not exist on the edges where the film touches the reels. Other than that it is PERFECTLY even across the film. I am shooting with a Leica M4, but some of these rolls were put through a Leica M3, both are perfectly light sealed by design, the bottom plate fits snugly, and I have never had an issue before. I will be going back to D76 and hoping the problem just goes away. I would like to say its just because its an old developer, but because it didn't happen to my friend, I am not able to say that yet, which is irritating me. I have shot this film before using D76 from both my cameras and no problem, so that would point to the developer, which as I Said before is some what old since they stopped making it a couple years ago, but only recently opened. Once again, I cant blame the developer until it consistently ruins film this way though. I Wonder then if there is some small nuance in how the developer is handled before or during developing that is causing an increase of 0.20 even density.

 

[erikg]

What you describe does sound like chemical fog, but I don't know why it wouldn't affect all rolls. Does the fog have a color to it, does it seem different in different angles of light?

 

[Nikanon]

What you describe does sound like chemical fog, but I don't know why it wouldn't affect all rolls. Does the fog have a color to it, does it seem different in different angles of light?

Im used to a colored stain from Pyro as this light tannish, and it seems somewhere between stain and fog. Thats whats driving me insane too, nothing is consistent. The only thing I can think of is that when mixing the developer, if the developer sits out too long before it is poured in to do the developing, it maybe oxidize just a little because its somewhat of an old developer, but thats a bit of a stretch too..

Ill attach some scans from the affected film, which surprisingly, look just fine.

 

[Nikanon]

Samples of the "fogged" film

 

[erikg]

I was thinking about dichroic fog as a possibility. If D-76 makes it go away you have part of the answer.

 

[Nikanon]

I was thinking about dichroic fog as a possibility. If D-76 makes it go away you have part of the answer.

Can't be that either, because even though I don't normally use an acid stop bath, I did use a Kodak indicator stop in a previous development with this film/ developer combo with all the same constants, and a few of the rolls had the fog still. Its absolutely maddening and elusive.

 

[erikg]

I don't see the connection with stop bath but that is long shot anyway.

 

[Nikanon]

I don't see the connection with stop bath but that is long shot anyway.

Isnt Dichoric fog when chemicals carry over from the developer to the fixer? A stop bath prevents it

 

[mfohl]

Do you buy your film in rolls, or are you rolling your own from bulk film?

 

[Doremus Scudder]

The positives you posted aren't much help. How about scanning the negatives in their entirety, including the sprocket holes, so we can get a better idea.

Some other random thoughts:

How old is your film? Has it been stored/handled correctly.
Are you seeing flare from something instead of fogging? Low-level flare raises fb-f.
Is there a possibility that you haven't fixed properly? Try refixing a neg in fresh fix if you have any doubt.
Dichroic fog gives a rainbow-like effect when the neg is viewed in glancing light. Check (although that's likely not your problem).
Are you bulk loading? Check your loader and how the bulk rolls are stored.

Thinking basically, fog comes from light or chemicals. I rather think that light is your culprit here, especially if it doesn't affect the entire negative. Keep looking for the source; camera, loading, storing, transferring to reels, the tanks themselves, etc., etc. And good luck.

Doremus

 

[Rick A]

You need to address one variable at a time. I would start with where you load the reels to make sure it is absolutly light tight. Next, I would consider whether you are getting a proper fix, you are doing multiple reel tanks and may not be getting enough agitation to properly fix all film. Then lastly, you should rethink developer. My thoughts are that you are either getting fogged in the loading, or your agitation regime is not sufficient to completely clear film.