View Full Version : Tray processing, John Sexton technique

Belden Lee Fodran
25-Jan-2000, 19:07
Hello fellow light catchers, I read a post awhile back where John Sexton uses a small plexiglass with pegs screwed onto it to hold the sheet film in place. You then drop the plate in the trays of chemicals and never come in contact with fil m. Does anyone have any more information on this type of device or where to purc hase it. Thanks in advance

Robert A. Zeichner
25-Jan-2000, 21:09
I've heard them referred to as "slosh trays" and have been using a couple of them for the past three years. They work great. Only thing is you have to make them yourself. This is not too difficult. The first thing you need is a set of 8x10 trays that will be big enough to hold the plastic panels, but not so big as to require a lot of developer. I found that some old Vivitar trays work great. What you want to do is draw out a plan view of the panel using 4 sheets of 4x5 film as a template. You need to center two dowels on each side of the film and leave about an 1/8" clearance so film won't bind. The inside edges of the four sheets can share dowels to keep size down and reduce the number of dowels needed. You can purchase some 1/4" plexi from a local plastics supply house. They will trim to size for a nominal charge. At that same place, you'll be able to buy a 1/4" plastic drill bit which you'll use to drill the holes for the dowels. Oh, also buy a length of 1/4" diameter plexi rod and a tube of plexi cement. The dowels need to be about 1-1/2" long. Cut with a hack saw and finish ends with a belt sander. Use short bursts of contact with sander or you'll melt the rod. If you have a drill press, use it! This will keep the holes perpendicular to the panel so they'll look nice and straight. Some people drill some additional holes under the film area to allow better circulation of chemistry. I haven't done this, but it seems to do a very even job regardless. Good luck and wear those eyeshields!

Sean Billy Bob Boy yates
25-Jan-2000, 21:22
Yah meen Dr. John stopped using a JOBO??? My god! All my photographic idols are falling from the pure techno-faith!!!

Chris Hawkins
25-Jan-2000, 22:35
Can someone post a sketch or picture of the this device? It sounds like a great idea. Thanks.

Alec Jones
26-Jan-2000, 00:53
I don't think you can post pics here, can you? I think I've got that drawing I saved from a magazine article. Send me an e-mail and I'll scan it.

John Hoenstine
26-Jan-2000, 07:59
The Mar/Apr 1990 issue of Darkroom & Creative Camera Techniques (now Photo Techniques) has an article by Howard Bond "Testing for Even Film Developement" which show photos of several different veriations of these devices.

Robert A. Zeichner
26-Jan-2000, 08:24
No, John Sexton still uses the Jobo as far as I know, as does Howard Bond. That is a wonderful system, just one I can't afford, nor have the space for.

Sergio Ortega
26-Jan-2000, 08:39

I made something similar. Not much to it. I skipped a step (the sheet of plexi glass), and just glued some thin strips of plastic directly onto the interior bo ttom of an 11x14 tray. I spaced these strips accordingly for 4x5 sheet film, an d cut shallow grooves into the strips so I could easily slip the edges of the sh eets into them.

The individual sheets are held in place by one grooved plastic strip on either s ide, suspended slightly above the bottom of the tray. I use three strips, posit ioned to hold four sheets of 4x5 film in the tray. I'm sure you can form a ment al picture without too much trouble.

Its real advantage is that you can process several sheets of 4x5 film simultaneo usly without the sheets coming into contact with one another during development/ agitation, thereby totally eliminating scratching of the emulsions during develo pment.

Scratching the emulsion during development has to be the most frustrating part o f LF development! I'm sure that all those LFers that have attempted that old t imer's trick of developing a bunch of sheets at the same time, using the so-call ed interleaving method, have discovered that this constant shuffling of the film s during development, when the emulsions are at their most delicate, invariably results in lots of scratches on the emulsion.

I could never understand how these legendary, grizzled LF sages could handle a b unch of sheets at the same time, much less keep track of each sheet's individual development time in total darkness. The scratching occurs when the very sharp edges of the other films inevitably comeinto contact with the other films during the shuffling process.

The act of smiply handling a single sheet of film with your hands will not scrat ch it. The device in question eliminates this film corner to emulsion contact.

Good luck, Sergio.

Chris Hawkins
28-Jan-2000, 07:23
Carlos R. Herrera kindly forwarded on a URL where the construction on the panels is detailed. http://philbard.com/panel.html

Thanks to Carlos!