Hi Everyone,

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.

Thanks

-- Kevin Kemner (kkemner@tatesnyderkimsey.com), February 17, 2001

Answers

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 Andrews (p.l.andrews@bham.ac.uk), February 19, 2001.

Pete,

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.

Thanks

-- Kevin (kkemner@tatesnyderkimsey.com), February 19, 2001.

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.
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.
You only get standing waves with continuous agitation methods, either by rotation or rocking.

-- Pete Andrews (p.l.andrews@bham.ac.uk), February 19, 2001.

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.)

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.

Cheers,

-- Kip Babington (cbabing3@swbell.net), February 24, 2001.