Arista Pro 400 high base fog

[dfoo]

I developed a roll of some newly rolled up AP 400 in Rodinal 1+25 along with a roll of Tri-X 400. The AP400 showed some very high base fog... I've used my bulk loader tonnes of times, and I cannot see the issue being the cartridge or the camera since the base fog is uniform and the camera was used for the Tri-X roll. Any clues as to the source of the issue?

 

[GSNfan]

The negatives, do you have that purple haze or they have come out clear?

 

[dfoo]

They're clear. They were developed in a 2 reel tank along with the Tri-X. The Tri-X is fine, the AP400 not so much! I'm not sure I can print through the fog, I've only made a contact sheet to this point.

 

[dfoo]

I shot a test roll this evening from the same bulk roll, one with rodinal 1+25, one with XTOL 1+2 for 10 minutes and one with XTOL 1+2 for 11.5 minutes. The film is drying so I haven't measured the base fog yet, but from eyeball it looks similar to the film I developed on Sunday. I measured the base fog of that and compared against the real Tri-X I developed in the same tank. Tri-X was 0.378. The AP 400 was 0.627. I measured some AP 400 from earlier last year and found that came in at 0.441.

Is it simply that the film is bad? Is that an abnormally bad level of base fog? Any ideas?

 

[David_Manning]

I've been wondering myself...what does it mean if the film has a slightly purple haze instead of clear? (I'm talking Arista/Tri-X).

 

[dfoo]

The purple haze is the antihalation dye. Its harmless but if you want to get rid of it see this endless thread on apug. http://www.apug.org/forums/forum37/...ew-tri-x-other-films-not-blue-green-cast.html

 

[David_Manning]

In my case, might it mean exhausted fixer? Would fresh fixer leave the negs clear?

 

[dfoo]

Most likely not, you can typically tell easily enough. If the negatives look milky your fixer is done. How many films have you fixed with the same batch? I normally just ignore the purple cast, it doesn't really bother me.

 

[Freakscene]

If your sample of AP400 is small you can't tell what the cause is. I have used thousands of rolls of AP400 without any difference in FB+Fog to Tri-X, suggesting that something has happened to your sample of AP400 in storage, transport or use that didn't happen to the Tri-X. Anything more is impossible to speculate.

Marty

 

[dfoo]

I just measured the base fog on the XTOL & Rodinal developed samples. It is all very similar to the roll I developed on Sunday. Right around 0.75. I also tried fixing some undeveloped samples of the following:

From the same lot:

- Exposed AP 400 leader. This was right around 0.3.
- Unexposed AP 400. This was right around 0.24.

From a different lot of AP 400.
- Unexposed AP 400. ~0.24.

I then measured some unexposed Tri-X. It measured ~0.21.

I have 10 other tins of 100 foot AP 400 in my fridge that I just bought. I'll roll up a sample of that tomorrow and shoot & develop and see what I get.

At this point it looks like I have 2 entire tins which are not all that usable which is pretty disappointing.

 

[tagheuer]

So... have you came to a conclusion about the remaining 10 cans ?

I'm interested on the development, since I plan to stock up some AP400, but a little hesitance when I saw this post.

Thx in advance.