Beginner in colour processing RA4 & C-41

Akki14 · May 2, 2007

Hiya all.

I'm just looking for some basic information.
Do you need a special tank for c-41 or is a paterson daylight tank lighttight enough? I'm intending on using some kind of aquarium (or nova) heater in a large storage container of water for a tempering bath for the chemicals and tank.
How do you do RA-4 processing in trays? How many trays would I need or would it be better to keep the chemicals in a tempering bath then do 1-tray developing?
I did a little bit of colour prints at university but we just fed the exposed paper through a machine. I have a huge nearlyfull box of 8x10 colour paper and an LPL C7700MX colour enlarger and a basic B&W darkroom setup so I'm part of the way there, I think.

I really don't know anything about either process. I'm currently looking at fotospeed's roomtemp RA4 kit and possibly speedibrews's Celer-41 kit.

tony lockerbie · May 2, 2007

Hi, the patterson tank will work fine for your C41. Temperature is fairly critical, especially with the dev, so your tempered bath would be ideal. I would also use a pre-soak with water to warm the film/tank to the correct temp. before adding your developer.
As for the RA-4, you could use trays but the temp problems could beat you as consistency is critical for you to get colour balance right.
Some folks use Jobo drums for the RA-4 with it's temp controlled bath, but they are a bit of a pain with constant wash/ drying.
If you are doing a lot, a second hand processor like a Fujimoto or Durst RCP etc. shouldn't cost too much these days and wil make your life much easier.
Good luck with it!
Tony

Nick Zentena · May 2, 2007

A few thoughts.

A plastic tank takes awhile to warm up. Don't dump your warm chemicals into a cold tank. The tank depending on size and temperture can easily drop the chemicals 5 degrees F.

I assume they have insulated picnic coolers in the UK. Much better then an open tray for a tempering bath. They have a lid so the heat stays inside. They are insulated. They'll hold more water then your average tray. The three things mean your chemicals will stay at a more stable temperture. Get a big enough one and you can put bottles of wash water in to warm to.

For paper Jobo drums are fine. With prices for used ones today you can get a few and avoid too many drying problems. If you wash the paper in the drum you'll also be washing the drum. Same issue with adding warm chemicals to a cold drum. But in this case I add a warm prewash. Simple.

Do a search. PE has explained room temperture RA-4 processsing in trays. Dev,stop,blix at the very least. I guess a wash tray at the end.

Neal · May 2, 2007

Dear Akki14,

Use the search engine and the keywords; Room Temperature RA-4. Lots of good stuff there.

Neal Wydra

bob100684 · May 2, 2007

pre-soak+c-41 is alledgedly a no no.

Photo Engineer · May 2, 2007

Presoak when drum processing C41 is a good idea. It brings the developer tank and equipment up to 100F and also helps prevent air bubbles (pinholes) on the surface.

PE

Snapshot · May 4, 2007

I purposed a heating pad for RA-4 development in trays. It maintains a temperature of approximatley 86F, which is good enough for prints. However, I find a drum easier to work with and cleaner as I don't spill liquids as don't have to fumble around in the dark.

As for C-41 development, I prefer to let a lab handle it. Even Wal-mart can process negatives and they do so for relatively low cost. This allows me to avoid the mess of C-41 chemistry.

Photo Engineer · May 4, 2007

I prefer tray processing at the ambient room temperature. A development time of 2' at 68 deg F and a small tweak to color balance brings me right up to the high temperature results.

I use RA-RT developer replenisher, as is.

PE

Akki14 · May 4, 2007

How long does RA4 stuff keep? I saw someone's post here recently on a nova press kit C-41 chemicals lasting for a year with only a slight colour shift in the negatives after it had been allegedly exhausted and outdated for a long time.

Just wondered if anyone has experimented with the printing stuff like that. At the moment I'm managing to still print with a working solution of print developer which is 10 days old. I pour it into a bottle after each session but each session runs many hours. I've not hit its exhaustion point of 100 8x10 prints yet, though.

Oh and if you work with trays in the dark, do you work only by feel (with gloves on) or can you put some glow in the dark tape on the edge of the tray? I've heard of someone who did that but I'd worry about paper fogging from that.

Photo Engineer · May 4, 2007

Use the proper safelight.

Glow tape will fog color paper. I have seen it happen.

PE

pentaxuser · May 4, 2007

If PE says something then given his background and experience, generally any endorsement is redundant but I'd certain endorse this about glow tape. I used to use it to locate the edge of paper in a paper trimmer to cut 8x10 into two pieces but it fogged the paper.

Unfortunately the only safelight I have found to be good enough to see what you are doing is a sodium type such as the DUKA10 or 50. Expect to pay at least £50-60 for one. Its the bulbs which are very expensive.

Others will say they have had success with LEDs. I cannot comment on these but I do know that if I had to do it in the dark and, yes, some manage it, then I'd probably give it up.

I think a decent colour safelight is an essential piece of kit.

pentaxuser

Neal · May 4, 2007

Dear Akki14,

Work without a safelight to begin with, it's a lot cheaper and not as hard as you think. As I work with trays, I wear examination gloves rather than trying to handle tongs in darkness. If you use tubes, the darkness is no problem at all (drying the tube out each time is the challenge).

Neal Wydra

Akki14 · May 4, 2007

Neal said:
Dear Akki14,

Work without a safelight to begin with, it's a lot cheaper and not as hard as you think. As I work with trays, I wear examination gloves rather than trying to handle tongs in darkness. If you use tubes, the darkness is no problem at all (drying the tube out each time is the challenge).

Neal Wydra

I use gloves currently (well, one glove. The other hand holds the timer). I cannot grab paper with those paper tongs to save my life. I've recently switched to normal washing up gloves since I kept ripping the examination gloves They're nitrile (?) coated gloves so they should be okay with chemicals I think.

I'll not bother looking into buying glow tape then, thanks for the advice there. Not sure about getting a colour safelight just yet. Too bad they don't sell the interchangeable domes for the paterson safelights since I have one of those already but with a red dome.

pentaxuser · May 4, 2007

Akki14 said:
I use gloves currently (well, one glove. The other hand holds the timer). I cannot grab paper with those paper tongs to save my life. I've recently switched to normal washing up gloves since I kept ripping the examination gloves They're nitrile (?) coated gloves so they should be okay with chemicals I think.

I'll not bother looking into buying glow tape then, thanks for the advice there. Not sure about getting a colour safelight just yet. Too bad they don't sell the interchangeable domes for the paterson safelights since I have one of those already but with a red dome.

You can get normal lights which are colour safe. Durst used to do a Tricolour. It had a 10-15W bulb but of course the filter material meant that the light was nothing like the output for B&W printing. I had one. If you wait about 20 mins for your eyes to adjust then you can just about see a hand in front of your face - oh and eating plenty carrots help.

Seriously you will just about get around the darkroom and would probably manage tray processing and Nova Quad tank processing a little easier still but you'll never see to do anything else.

Putting on the room light means that you have to start the whole sequence over again of getting your eyes used to the incredibly low light.

With a DUKA its a matter of seconds to adjust. If you already know that colour printing is going to be a permanent part of your photographic life then the money spent amounts to a tiny amount per print.

pentaxuser

Bob Carnie · May 4, 2007

I am going back quite a few years, but at college we used Kodak K16's for semi automatic processing in a small sink. Each room had one and they worked wonderful for printing RA4 prints.
If you google and find such an item it would be cheap, but very doable in a small darkroom and very efficient.
Basically a smooth drum which rotated in a tempered holding tank that contained the chemicals and water for final wash.
Print was laid onto a netting* emulsion up* that was presoaking in water and then placed emulsion down on the rotating drum. As time elapsed the dev was quick dumped and replaced by bleach fix, then quick dumped and then washed.
Print was heat dried and finished.Used this machine for two years and was very happy with it.

Beginner in colour processing RA4 & C-41

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