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schafphoto
2-Nov-2016, 19:19
Something is askew with my development. Those of you with Pro-lab experience can hopefully shed some light on the issue.
• Sitte Tischer dip and dunk automated processor and Refrema automated processor at second lab.
• 20 Celsius and processing times around 6-8 minutes.
• Clayton F76 Developer (auto replenishment).
• Film is hung on 3 foot tall racks, with 6 or 7 sheets on a rack at a clipped at a 30 angle to facilitate drainage.
• Agitation was changed from almost constant nitrogen bursts to very little – one per minute – with almost no difference in mottling (except contrast/density).
• Dev-Dev-Stop-Wash-Fix-HypoClear-Wash-dry.
• Film is fresh usually used within a month of buying at Freestyle/Samys/B&H and usually has two years before expiry.
• This mottling is happening to many sheets at a time – I expose about 1000 sheets a year.
• Longer processing times seem to be better but this does not solve the problem completely and lower contrast is preferred so pushing the film is not a great solution.
• It’s not the camera or the lens or a light leak or bellows or one of my 150 holders, all that has been tested and is fine multiple cameras.


Part 1: 2013-2014 Generally there is a very slight mottling in the perfect sky areas – barely noticeable but clearly not optimum.
My solution was to change from my preferred HP5 stock to TMY and have he photo lab ditch the Clayton F76 and start using TMX-RS developer in 2015. This made the problem
worse with HP5 but seemed to solve the problem with TMY when the agitation was turned up to 11 (as Nigel Tufnel would say). I remember teaching people to develop 35mm film
in the 1980s when TMX first came out and realizing that if I agitated like in the early TRI-X days the film would be flat and unempowering, but if I banged that little can on the counter and
shook the hell out of the TMX it looked much better. Agitation always seemed to agree with TMX/TMY but this is an oversimplification.

Even TRI-X 320 5x7 seemed to be happy in the new TMX-RS soup. Problems were minimized if not solved.

Part 2: Now/2016 my old local lab is ditching its processing line to go fully digital (it was inevitable). So I find a new lab a few miles away. Seems like a better setup, very exacting, better machine (Refrema), tight control strips.
They seem eager to process my film so we started the test runs last week. Then I see it... Mottling in the sky areas with my TRI-X320 and TMY-400 films.
They have been using Clayton F76 for years.

I now have new boxes of Ilford HP5 4x5 and 5x7 on the way but I am worried this will start another wild goose chase. I posted the problem on Ilford’s forum but it’s not a film-stock thing, it’s something in the soup.
I could go on, but what do you think? I know somebody has seen this before. I have more samples if that helps.

I appreciate the help.

-Stephen

schafphoto
2-Nov-2016, 19:21
Other mottling samples.

156919

156920