|
|
|
-
 Originally Posted by Ronald Moravec
My tests indicate as long as the film is submerged for rest time between agitations, make no difference.
In fact the best agitaion removes the film from the developer during agitation.
Paterson tanks are particularly nice because the empty space in the top makes for significant developer movement. You never get streaks or marks with a PATERSON IF YOU FOLLOW INSTRUCTIONS.
In commercial processing, I was taught when developing reels or sheet film in the 3.5 gal. tank to lift the film completely out of the tank twice during an agitation cycle and allow to drain before returning it to the tank. Never had a problem.
-
Fred is absolutely correct. 4x5 film in hangars is best agitated this exact way also unless you have a nitrogen burst system.
For 35mm, a perfect way is to use a double film tank, two reels with film in the bottom one only, and only enough liquid to cover the film/lower reel. the times are exactly the same a single reel tank. I have done this many times and get perfect evenly developed negs.
It also proves there is no such thing a surge marks or localized overagitation. If inversion in a half full tank does not induce overagitation, nothing will. People who try to make slow gentle agitation to solve an unevendevelopment problem are creating even more more problems.
The large amount of empty space in the top of a Patterson tank does the same thing, by allowing extreme solution movement during inversion. It also is perfect for filling as there is a funnel that makes you fill bottom up and not be spilling developer over the film edge when filling. This actually introduces part of the film to developer earlier than the rest and can really mark the film for concentrated developers and short overall times.
Lowering the film into a prefilled tank accomplishes the same thing as the Patterson funnel. This is the best way to work with a stainless type tank and is the only way to do it as the tanks get larger. That is why larger tanks were furnished with lift rods.
You can safely empty developer through the top up to 4 reel tanks.
Fix does not matter as it is process that goes to completion and stops. Really good agitation is important with fix also otherwise there tends to be an unfixed streak down the center. With a single reel tank, after 2/3 the fix time, I pull the film out completely three times. You can do this in day light as development is no longer possible.
-
Just to add my 2 cents. I just developed a couple of 35mm test rolls in a Patersn tank that holds 3 films. Developed one at a time, 300ml of chems each, inversion style and they came out fine as far as I can see. No air bells (I should hope not with the slapping that tank got) or streaks etc. So, yes it dose work 
|
|
Adv Reply
