My question to Ron Mowery:
Do you have any insight as to how the length of
processing time might affect grain and acutance with
respect to b&w films? What I am referring to is an
opinion by at least one pro I know who believes
that emulsion swelling due to more extended wet time
can affect grain characteristics. I know of no
research in this regard, but perhaps it has been done.
Ron's reply:
I can say that swell affects development rate more
than it does grain. Hardness affects grain and swell
more than development time.
Basically, as you incrsase development time you get
higher contrast and higher mid tone speed (density)
and that contributes to the grain, but it is probably
about the same if you normalized it for density.
In that latter sense then, you can say development can
appear to increase grain by increasing image contrast.
Remember though that grain measurements start low,
increase with density and then decrease again as you
pack the developed silver closer together. This is
normal because the closer the silver image is, the
less apparent grain.
I know of no experimental data that shows that
development related swell changes grain, but all of
the above are observations on speed, grain and
contrast that we made at equivalent swell. And, as
you decrease swell, you decrease development. If you
increase the development back to the same density,
then grain goes up again.
Bottom line is that you get normal grain from normal
development, and get worse grain from overdevelopment,
but it is unrelated to swell, instead it is an effect
of overdevelopment.
My follow-up:
Can I also conclude that swell as a result of extended
wash time wouldalso not materially affect grain
characteristics?
Ron's reply:
Read the article by Dick Dickerson and Sylvia Zawadski
in the latest Photo Techniques.
I may do an experiment (with sheet film) to see if I can detect any difference with extended washing vs. the Ilford regimen. I don't doubt Ron's conclusion, but sacrificing two sheets of film might make a fun little experiment.
