Color contact printing

[pkr1979]

Thanks again all,

Do you guys prefer trays or Jobo? I figured Id use Jobo as temperature control is easier. Im trying the new Tetenal Magic Box RA-4 (https://www.fotoimpex.com/chemistry/...developer.html), however... my German is slightly rubbish and copy paste to Google Translate isnt working: https://www.fotoimpex.com/shop/image...Datenblatt.pdf soooooo I dont really know what it says. Anyway, its pretty short times, and in this regard I suppose trays might be more convenient. But, what happens if the exposed paper is too long in the developer?

Cheers
Peter

[agregov]

I would not use trays. The chemistry is pretty potent. Also, you're working in complete darkness. Tough to see what you're doing. I would load a Jobo drum (again in complete darkness), then switch on the lights and make your development run (developer, Blix, washes). Note, you'll ideally want your print dry to evaluate color casts. A print dryer would be helpful.

[koraks]

I find trays the most convenient personally. No temperature condition necessary, just do it all at room temperature with extended processing time. 90 seconds development does it for me. Drums are too much of a hassle with drying them in between prints/strips and there's a plethora of threads from people who try to solve problems with unevenness and consistency that suggests drums are certainly not a superior or trouble free approach.

[agregov]

I personally have found no need to dry drums in-between prints. Simply pre-wet the paper in the drum with a water rinse going before going into the developer step. I've testing with dry drums versus wet drums/pre-wetting and have seen zero difference in quality of the final print. That said, RA4 printing in a Jobo isn't all that fun. No comparison to working with a proper paper processor (dry in dry out). But obviously, those are hard to come by these days. You do still need a drying step with trays for accurate color correction. If you're after a side project for making a few color RA4 prints for fun, by all means try trays. But for serious color printing work, I can't see how working in trays is a scalable system for making fine art quality RA4 work. At minimum, you'd need a Jobo. Better yet, a color processor like a Fujimoto. For myself, if I didn't have access to a RA4 processor, I would simply move to scanning and print via inkjet for color.

[koraks]

A hairdryer works quite well to dry a test strip within a few seconds. Squeegee first, then blast with hot air.

Trays of course limit the size at which you can print conveniently. I don't go beyond about 30x50cm personally.

Of course an rt processor is nice, but as you pointed out, you need to run a decent volume through it to make it worthwhile with the warmup times and cleaning racks etc.

[LabRat]

Paper speed not too different than B/W RC (fast)... Probably less than a few seconds, so use an enlarging timer that will also set to fractions of a seconds...

Usually have to work fast with Type C papers...

Depending on light source, negs etc, start by setting y/m to 20 to 40cc, and take notes when you find it, and use that for the next starting point... Expect to make a bunch of test strips sooner to get into ballpark...

Steve K

[pkr1979]

I'm tempted to try doing this at room temp. But doesn't this have any other consequences then longer development time (contrast/saturation)?
Also, developing paper - this isn't something that is done to completion? Its possible to overdevelop paper?

[koraks]

There's a small difference in filtration at lower temperatures, but adjusted for this, prints are indistinguishable. Development is pretty much to completion, but just like with b&w paper, the margin isn't endless. There is however a margin; eg I noticed no difference between 90 and 120 seconds in my room temp prints.
Do make sure to blix adequately. Blix speed is of course also slower at lower temperatures. On the other hand, official blix times appear to be rather conservative.

[pkr1979]

Do make sure to blix adequately. Blix speed is of course also slower at lower temperatures. On the other hand, official blix times appear to be rather conservative.

What kind of Blix times do you operate with when developing at room temp?

[koraks]

What kind of Blix times do you operate with when developing at room temp?

90 seconds for final prints, but for test strips often only 20-30 seconds.