In a recent thread, a reference appeared to the idea that prolonged "wet time" (time a film spends wet during developing, fixing and washing) might increase the grain.

Does anyone have any information or views on this?

Thanks in advance,

Ed

-- Ed Hurst (BullMoo@hotmail.com), January 29, 2002

Answers

I have never heard this in reference to wash water. Prolonged development however, can increase grain.

-- Ed Farmer (photography2k@hotmail.com), January 29, 2002.

Extended time in liquids can cause the emulsion to swell and cause an increase in grain clumping. The warmer the water, the more likely this is too happen. Newer films such as T-Grain are less susceptible to this than older emulsions. However, I wouldn't worry about this if you keep all your liquid temperatures at or below 72F, and total wet time of 45 minutes or less. Sudden changes in temperature are not good for grain either.

-- Michael Feldman (mfeldman@qwest.net), January 29, 2002.

I agree with Michael's consideration. Not just T-grain films but FP4+ and HP5+ also have hardened gelatine, resistant to higher processing/washing temperature. The number he gave, 72F is a safe one and it can be higher in this case. However, the numbers people give seem to lack clearly and reliably observable evidences (for example, small difference in a too small sample size) and they are just good rough guides, as many other things are. Going a bit more toward radical side, even the 20C/68F is not the definite standard. Eastman Kodak Company used to recommend 18C/65F for films and 21C/70F for prints. I even heared/read several times that they recommended 18C because this is the annual average temperature in Rochester, NY. Anyone knows the truth??

Just to clarify thing a bit, I like to note that the reason long wet time should be avoided with paper is different. Long wet time may lose some of the paper base brightness. Mechanical strength and stability of the emulsion and paper base can be sacrificed. (Even before these, you get more trouble in drying them flat)

-- Ryuji Suzuki (rsuzuki@rs.cncdsl.com), January 29, 2002.

This business of grain 'growth' after development is a complete myth as far as I can tell.
Kodak state in one of their technical pubs that "Contrary to widely held opinion, there is little migration or physical joining of individual grains.". An online version of that paper can be seen here.

Anyway, I think you could prove this for yourself very easily, one way or the other.
Make a print from a section of a neg, large enough to see the grain clearly. Re-wash the negative for an extended time, and then reprint the same section.
If you can show any visible difference in the before and after prints, then I'll donate an unspecified prize to you, or to a charity of your choice.
The size of the prize will be commensurate with the degree of grain growth shown.

-- Pete Andrews (p.l.andrews@bham.ac.uk), January 30, 2002.

Nice offer Pete. This is one more of those things, that almost qualify as myths, people worry to much about. My students ask questions like, "Can I wash my film for to long?" My usual answer is, "Not during a four hour class, you can't!"

-- Ed Farmer (photography2k@hotmail.com), January 30, 2002.

My view: wet time to grain relation is inconclusive.

I have read several articles about this sort of issues, but none of them is convincing. Theoretical argument from either side is not too convincing and does not exclude the possibility of the other. Experimental arguments are based on too few data points to conclude anything meaningful (it just tells that the phenomenon is irrelevant for practical purposes).

I just don't want to sound like I support either side of this wet time - grain controversy. This is not because I don't want to sound controversial, but instead because I don't have any strong reason or urge to say this issue is a complete myth. I would like to have a good reason before I say something against widely held views (whether useful or not). I'm not brave enough to believe what Kodak states without any reasoning or data. (Did I say something like this before?)

My recommendation: Reasonable temperature selection and stability are important not to stress/damage the emulsion anyway. Wet time is much less critical with film than paper, but as a general statement, the shorter the less damage to the gelatine.

-- Ryuji Suzuki (rsuzuki@rs.cncdsl.com), January 30, 2002.

I believe this idea originated with Bob Schwalberg but no examples were shown to back up the assertion. I've never been able to see any difference.

-- John Hicks (jhicks31@bellsouth.net), January 30, 2002.