Dichroic Stains

[Justin Low]

I've not seen many threads on this, so I'll start one.

I just developed a roll of 400TX at 30°C using RodinalX (Xtol blended with Rodinal, ratio for Rodinal+Xtol+Water is 1+20+80). I use a single reel stainless steel tank, and the volume of chemistry used is 250ml. I use a water stop followed by fresh TF4 fixer. Tap water was used for all chemistry.

Now, after removing the film from the fixer, I see many small spots, around 2mm in diameter randomly scattered on the film. These dots appear green at a certain angle, but disappear at other angles. Reading up, it sounds like dichroic stains to me (but why not the whole film? why just spots?).

Now, the book I read (Roger Hicks' Darkroom Basics and Beyond) mentions that dichroic stains are uncommon nowadays, but he does not mention the effects or consequences.

So what are the consequences of dichroic stains on films? Incidentally, after the film dried, the spots were no longer visible. I have not tested rewetting the film.

 

[Ed Sukach]

So what are the consequences of dichroic stains on films? Incidentally, after the film dried, the spots were no longer visible. I have not tested rewetting the film.

Is there any indication of "spotting" or degradation in printing?

If the spots to do re-appear with rewetting, I don't think I'd worry much about them.

Just an after thought: Do you use a wetting agent as a last step in processing?

 

[titrisol]

were the spots there after washing?
Did you use phoot-flo or similar?

 

[Justin Low]

Yes the spots are there before and after washing. I use Edwal LFN. They disappear upon drying.

I don't have access to a darkroom but will scan them later to see if there's any effect.

 

[Justin Low]

Doesn't seem like there's a problem with the scans. So how do the dichroic stains affect whatever they affect? Is it just a cosmetic thing to scare me during processing?

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