processing single 5x7 sheet in roll film tank?

[Rayt]

Is it possible to develop one sheet of 5x7 in a daylight roll film tank? The emulsion side will be facing in but is it ok for the shiny side to rest against the tank or should I rig something i.e. taco-ing so there is a gap so the developer will freely flow around both sides of the film? The next best thing is an Orbital tank but that only takes two sheets so I'd rather use what I already have if only one at a time. I won't consider the Jobo 3006 or any equivalent given I am in Hong Kong and these things are not available here. Thanks.

[Jay DeFehr]

Yes, it should be fine. The film will flex away from the tank walls enough to get solutions behind the film.

[Michael Alpert]

Is it possible to develop one sheet of 5x7 in a daylight roll film tank? The emulsion side will be facing in but is it ok for the shiny side to rest against the tank or should I rig something i.e. taco-ing so there is a gap so the developer will freely flow around both sides of the film? The next best thing is an Orbital tank but that only takes two sheets so I'd rather use what I already have if only one at a time. I won't consider the Jobo 3006 or any equivalent given I am in Hong Kong and these things are not available here. Thanks.

I am not sure that it will be fine, but I've never tried it. The back of the film touching the tank may not be very important, but the evenness (or unevenness) of agitation will be decisive. I would think that tray processing would be easier, especially processing one sheet at a time. Still, you've thought of an idea that is, as for as I know, untested. I would try it on test negatives first. Please let us know if it works.

[domaz]

I develop my 5x7 sheets in a Jobo 1500 series tank with no reels, I can fit two sheets into it just fine, emulsion side facing inward. I then throw the sheets into a tray of fixer after I'm done with developer and stop bath. The taco method isn't all it's cracked up to be IMO- you end up with marks on the film from whatever you use to hold the film in a "taco" (screening, rubber band etc.. both make marks). I've had much better cleaner results putting the 5x7 sheets in my Jobo tank BTZS style.

[Rick Olson]

Rayt ... I do this with my 5x7 film in a Patterson roll-film tank it works great. The film does flex slightly, allowing the back to clear. I get very evenly developed negatives processed this way.

[Jay DeFehr]

I've developed hundreds of negatives this way, but not 5x7, and not with the OP's equipment, which is why I wrote "should work fine". The principle is sound, and well tested. With continuous agitation a tank provides more random agitation patterns, and therefore more even development than tray development does. If you intend to use intermittent agitation, be sure you have enough developer in your tank to completely cover the film during rest periods.

[Rayt]

Excellent! I have been wanting to get into 5x7 but the local labs won't do anything larger than 4x5. I use a 2521 for that and now have an option for 5x7. Thanks very much for the advice.