Developing Technique, Sheet Film in a Patterson Roll Tank

Hi Everyone,

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On occasion I do some 8x10 work. Not enough to justify a Jobo or the like. I've been trying to refine a technique to do single sheets in a large Patterson roll film developer but have difficulties with development along the edges of the film. I think one edge is getting over-agitation and the other might be exhausting. I use a classic infinity loop agitiation 10 seconds every minute. Can anyone offer some refinements or advice? Tray development is not an option in my current set-up.

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Thanks

It's highly unlikely that you're getting selective agitation. What's

more likely is that the bottom edge is getting longer in the developer

due to the filling and emptying time of the tank.

Pete,

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I would have thought the same if the density dropped off in an even

fashion but there's very clearly a line between the area of heavy

density and normal density. One suggestion I've heard is that allow

the film to sit on the bottom of the tank is puts it in a zone of

turbulance when the tank is inverted. I don't know what to say about

the other edge which is very clearly underdeveloped.

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Thanks

A sharply defined line suggests to me even more that it's not an

agitation problem, but caused by the developer not fully covering the

film. <br>As long as there's sufficient air space in the tank,

inversion will completely mix the developer, using this 'infinity

loop' method (never heard of it, sounds like new-age piffle), or just

turning the tank upside down any old way.<br>You only get standing

waves with continuous agitation methods, either by rotation or

rocking.

Filling time shouldn't be an issue with Paterson tanks. I did 8 rolls

at once in one of their tanks two days ago, and got the 2.5 liters of

developer completely poured in within about 12 seconds. A sharp line

of density change certainly sounds like not enough developer in the

tank (unless, of course, the lighter density section was at the bottom

of the tank, in which case I haven't a clue as to cause.)

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I'm curious, though, as to how you put the film in the tank. Did you

just roll it up, emulsion side in, and let it expand against the sides

of the tank, or did you manage to cobble together two reel halves to

hold it in a spiral? I'm thinking of doing some 4x5 sheets (for the

first time in decades) and would like to take advantage of the rapid

fill and iversion agitation possibilities of my Paterson tanks, but

haven't figured out yet how to put the film in the tank.

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Cheers,