View Full Version : RA-4 Color Processing Times

12-Feb-2009, 12:09
Anyone out there familiar with printing RA-4 in a Jobo machine?

The Jobo processing manual places the time in the developer at 1 minute or 60 seconds whereas the Kodak data sheet has it at 45 seconds specifying Kodak paper (I'm currently printing on Fuji Crystal Archive Glossy). I have found Jobo to be in lock step with Kodak with regard to processing times and chemistry volumes (C-41) and it even amended its earlier manual to go with the Kodak recommended volumne of RA-4 chemistry per sheet. I'm wondering if there has been a change since the manual was last printed dropping the developer time down to 45 seconds from 1 minute. I am using the following Kodak RA-4 chemistry:

Kodak Extacolor RA Developer Replenisher RT with Developer Starter.
Kodak Ektacolor RA Bleach-Fix & Replinsher.

Also, if you have Ra-4 printing experience, can you suggest a starting filter pack for Fuji Crystal Archive? I'm printing with a Beseler 45S color head. The Beseler manual suggests a starting filer pack of 90Y, 50M, and at a recent Comunity College they used 45Y, 45M with Saunders enlargers and heads.

Thanks and,

Keep Shooting!

Juergen Sattler
12-Feb-2009, 12:35
60sec. always worked for me in my ATL2 Plus processor. The recommended filter settings for my Saunders enlargers were way off - it honestly would not help you to give you mine. It truely is a trial and error process and will take some time until you've got your enlarger calibrated.

12-Feb-2009, 17:04
My CP-51 uses 45 seconds per bath with the chemistry you are using at 35 C/95 F. Not sure which JOBO machine you have or temp you are using.

12-Feb-2009, 19:14
I have run a lot of RA 4 machines, but not a JOBO, and the processing time for paper is generally about 45-50 sec at 35C, although a 60 sec time might work also, as it would be compensated for in printing. However, too far off the recommended time and the colour curves will go a bit wonky. The Kodak paper and the Fuji Crystal Archive will process fine through the same chem. at the same time and temp., I have used these side by side like this in the past and it has not been any problem. If you have can use Kodak or Fuji control strips to verify that the processor is running properly.
Typical filter packs vary considerably, and usually it would be something like 40M, 60Y, but as a previous poster noted, this is highly individual, and you will have to do your own testing to get to a good starting point.
Use a "normal", well exposed neg shot in daylight to get a standard, or else one typical of the lighting you will use.
Hope this helps!

12-Feb-2009, 21:41
Thanks for the replys on this everyone.

I'm using a Jobo CPA-2 processor at 95F for RA-4 as recommended by both Jobo and Kodak for rotary processing.

This may sound like a very elementary question but what would the colors on a contact sheet appear "unreal" if over or under developed by 15 seconds?



Mick Fagan
13-Feb-2009, 04:00
The colour of an RA4 contact sheet will be slightly different if you use different developing times, that is a given. It is exactly the same scenario for enlarged prints, different times, different colours, with a density difference to boot.

You should find a certain time/temp/agitation system and stick to it. It doesn't really matter if your times are 60 seconds or whatever, just have repeatability for each successive development. Consistency is the one thing you must be able to do, otherwise you'll be looking at different density and colour changes with each print, expensive.

Contact prints be they RA4 or B&W or whatever, will always be just slightly different than an aerial projection print (enlarged). The main reason is that the emulsion to emulsion contact prints, will give you pretty much the best tonal rendition possible, slightly better than projection prints.


13-Feb-2009, 16:29
I'm using a CPP-2 at home. I go in the following order:

30 seconds Pre-wet
1 minute developer
30 seconds stop bath
30 seconds rinse
1 minute blix
1:30 wash (3 changes)

13-Feb-2009, 16:55
Over or under by 15 sec, might be hard to spot, especially over. Under dev will give less Dmax (black), and it will be lighter, and though 15 sec isn't much, if you went from 45 sec to 30/35 sec., the Dmax would definitely suffer, but if you had an image without much black, you may not notice, except for the density. 15 sec over, will give you more density, and likely won't mess anything up.
Contrast would suffer a bit too, but not as much you might think. The main developing agent is very resilient, which is what makes RA4 a nice process, compared to others I've used.
Here is where I am a bit less experienced, as I'm a techie, not a chemist, so others may correct me. Modern colour processes rely on a specific developing time, so that the developer soaks into each layer sequentialy, to give correct development for each colour layer. So if the time/temp (for instance 80F at 5 min) is altered very far, the layers will not develop correctly, and what we call cross curves appear. Which is simply the colour in the highlights, is different than the shadows, and then it becomes impossible to get a good colour balance on your print. Pink highlights, and cyan/green shadows for instance.
Again, I hope this helps!

Drew Wiley
13-Feb-2009, 17:15
I use Kodak chemistry at 84F for 2 min, including a 10 sec drain, either in CPI or other
semi-manual drums up to 30x40 print size (not Jobo). Like the better margin of error provided by a slightly longer dev time, especially for larger prints. Don't want to comment on filtration because my enlargers are so unique (additive color).

Stephen Willard
14-Feb-2009, 00:14

I use both the CP-51 roller transport processor and the JOBO ATL Plus 2 to processor to develop RA-4 Crystal Archive glossy papers. For the CP-52 I use 45 sec, and for the JOBO I use 1 min. The difference in the time is to allow 15 sec to drain the JOBO drum. Its no more complicated than that. The results I get are essentially identical.

Hope this helps...

Bert Hillebrand
23-Dec-2009, 10:10
Does anybody have any experience, good or bad with using C-41 Bleach-Fix in the RA-4 print process? I'm interested because I have a large stock which I would use up before investing in more RA-4 Bleach-Fix.
Bert Hillebrand

23-Dec-2009, 12:32
Hi Bert,

I have read on apug that some folks are using c-41 bleach and fix on RA-4. C-41 bleach is quite expensive compared to RA-4 Blix which is retailed priced at $22.95 for 10 liters of replenisher which translates to 12 liters of working solution or about $2/liter.


30-Nov-2010, 09:58
I use Kodak chemistry at 84F for 2 min, including a 10 sec drain, either in CPI or other
semi-manual drums up to 30x40 print size (not Jobo). Like the better margin of error provided by a slightly longer dev time, especially for larger prints.

By CPI do you mean a 'Consolidated Photographic Industries' CPI-40 processor? Could you post some photos of it? Never seen one of these. I am currently trying to find a way to evenly develop a 30x40" RA4 print in a drainage pipe.


11-May-2013, 16:03
Another Gem!

I've finally wised up and kick book marks of these informative threads into a separate folder that I can go back too.

I wish there was some way of printing a multipage thread in one step.