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Hey thanks for the heads up. I'll look for one of plug-in variable frequency drives. Are they expensive?
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Good Evening, Mainecooniac,
After using rotary processing for about thirty years and experiencing virtually no problems with it, I can offer nothing based on scientific measurement or experimentation, but from the extensive experience, I can suggest the following in response the last Jonnielvis post:
1--My Beseler motor base (it's nonreversible with only one constant speed) rotates my Chromega drum at a rate of about 20 RPM, which I would guess is considered fairly fast; I haven't used any other motor base so I can't make any comparisons. I do a manual reversal after the first minute and every thirty seconds thereafter. I have never seen any failure to remove the anti-halation backings from film. I do only 4 x 5 film and have the ribs and the spacer in place to keep sheets secure; perhaps this helps randomize the circulation during processing.
2--I always use a water pre-soak for about 2 minutes; most of the anti-halation coating seems to be disolved during this step, judging by the color of the disposed water.
3--As I noted in my first response above, I'm generous with my solution amounts, but I'm sure that the film is above the solutions at least as much as it is below them. I can't see that this is any problem, since enough solution remains on the film surface to continue acting throughout the rotation.
4--I haven't used the Beseler drum; perhaps there's something about it which causes difficulties my Chromega does not.
5--My film has been predominantly Kodak, but results with occasional use of others (Foma, J & C, a little Ilford) have been just as satisfactory as with Kodak.
I confess that I am at a loss to explain the problems Johnielvis has cited, but I doubt that the drum rotation speed is likely to be a significant factor.
Konical
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Thanks Konical. Another perspective is always good. I think a 2 minute presoak is a good idea to remove the antihalation coating. I use Foma roll film and there's always bluish green tint in my developer. Never done rotary film processing before but done a lot of RA print processing in a tube. The advantages are obvious. A less chemicals are needed and processing can be done with the lights on.
Best,
Don
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drives are like 25 bucks or something...stillwaiting for mine
well, I'm at a loss to explain how I have the problems I have...other people have them too...I guess all the years I've been doing it wrong...hand processed four 11x14 sheets wiht the hand slow roll method this morning--absolute perfection...AND less chemicals than before...just see if you get the problems that everyone else seems to get.
I've mentioned these problems before about 8x10 and 11x14 sheets but the roll film users and 4x5 rotary processors say they have no such problems, therefore I must be "doing it wrong".
all I know is I ran one of these with liquid in it opend up with a plastic see through barrier on one side and let me tell you---rotational speed has EVERY:THING to do with the flow regeme in that rolling tube--that's where I got my facts from--experimentation and observation.
you'll see--things that work with 4x5 do not work with 8x10 some of the time and almost never with 11x14---which is where i"M having the real problems with
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