FotoDave@aol.com
Sat, 20 Feb 1999 21:35:46 -0500 (EST)
In a message dated 2/19/99, PM 02:11:53, alt-photo-process-l@skyway.usask.ca
writes:
<<They also warn that "continuous agaitation interferes with the formation of
sharpness-enhancing edge effects. Because continuous agitation exaggerates
highlight development at the expense of shadow development it also results
in lower speed and a shorter tonal scale.
I agree with what they say about the effect of continuous agitation, but we
must remember that rotary processing is NOT continuous agitation. The film is
not continuously agitation in the chemical. Depending on the amount of
chemical used, 1/2 to 3/4 of the time the film is not in the chemical, so
local exhaustion can still happen. One has to test out the amount of dilution
to get the desired edge effect.
>> One way of compensating for this
is to use a more dilute developer. Whatever developer you use, dilute it
with at least 30% more water and increase your development time." (p.34)
Any comments re:any developer or especially PMK?
I am not using PMK (yet?), but with with standard developer like D76, one has
to use more dilution than 30%. One must observe the capacity requirement and
process long. I tried the lowest rpm of my Jobo but found that adjacency
effect can happen even with the highest (75 rpm) rotation.
But I didn't do much tests on original negatives. I want them to be normal. I
am now doing tests on enlarged negatives, and I can clearly see the adjacency
effect.
>> They mention three "solutions" to the developer oxidation. 1) Splitting
development time into two halves, each with fresh developer. 2) add 0.3g/L
of sodium sulfite to working solution. 3) use 30% more stock solution A
when making developer. No mention of Rollo Pyro. What do people think of
their third idea (added Sol A) which they claim is the best alternative?
>>
Again, for non pyro, I use method #2. I am not sure what they truly mean by
"best." They probably mean easiest. I just checked the PMK formula. It seems
to me that one can probably just add 20g. sulfite to the stock without
affecting much or anything at all (the pH is mainly set by the metaborate) if
#2 is desired. This way one doesn't have to add the sulfite before every run.
But that's just my guess.
Dave S
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