RA-4 Room Temp Lack of Contrast
I am using Kodak chemicals and normally I process at 94 degrees using a Jobo CPE-2 processor.
I wanted to try batch processing at room temp using a vertical slot processor. I developed at 68 degrees for 2 minutes then 2 minutes wash then 2 minutes BLIX then 5 minutes wash. I added 5 Yellow as a correction and added 1/4 F stop more time in exposure. The resultant prints at room temperature lack the contrast that I am used to using the Jobo at 94 degrees. It is normal to have reduced contrast using RA-4 at room temp?
YOu could try increasing time to 2 1/2 or 3 min. and further increasing exposure.
IMHO, either due to my inadequacies or due to actual problems with this approach, I have never been able to attain a room temp. print that looks as good as a print I can make on my RA-4 machine.
I have made dozens.
Use Kodak RA-RT developer replenisher mixed as per instructions. I mix 1/2 of a 10 liter kit at one time.
Sorry for your problems. I hope this helps.
Since you did not specify what developer you used, I would guess that it is the developer if it is not the RA-RT.
Found the Problem! Thanks Photo Engineer!
I am using Kodak RA-4 RT replenisher mixed as developer.
I found the problem, I was going from developer to a 2 minute wash instead of going to a :30 stop then a 1 minute wash. I found this by searching the Photo.net archive and someone else was making the same mistake and Photo Engineer made a clear point to let them know that stop was needed as a anti-fogging agent. THANK YOU PHOTO ENGINEER! :-)
So to recap the "new" process:
1: Expose with 10Y added and 1 F Stop more exposure.
2: Develop in RA-4 RT Replenisher Mixed as Developer for 2 Minutes at 68 degrees.
3: Stop in 28 mL of KODAK Glacial Acetic Acid per litre of water formula for 30 seconds at 68 degrees.
4: Wash 1 Minute In Water at 68 degrees.
5: BLIX in Kodak RA-4 Bleach Fix for 2 Minutes at 68 degrees.
6: Wash for 5 Minutes In Water at 75 degrees.
Why are you using a water bath after your stop? The stop's other purpose is to prevent developer carryover and contamination of your blix. So you don't need to use water AND stop. Water does the same thing, just not as well.
Another thing you can do to see if you're getting full development is to develop at 2 min. and then develop at 2 1/2 min with the same exposure. If you see any difference with 2 1/2 as opposed to 2 (more density), then change to 2 1/2 min. Personally, I don't see a difference, so I've stuck with 2 min.
So here's what you should have your times at:
2-2 1/2 min. Developer room temp.
1/2 min. SB
2-2 1/2 min. Blix.
5 min. Wash
Last edited by FilmIs4Ever; 05-21-2008 at 12:55 PM. Click to view previous post history.
Reason: None of your business
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I am using a wash after stop based on Kodak's recommendations here:
Well, do what you want, but it's needless. It even says *optional wash* in the link you gave me, and only 30 sec. There's no difference in quality or print longevity, maybe a minimal benefit to your blix.
Originally Posted by RellikJM
What is a slot processor exactly? I've only ever heard of drum, tray, and roller transport machines. Do you have to change solutions manually? If it's automated, then an extra minute wouldn't be that big of a deal. After 20 or 30 runs through the cycle though, changing solutions by hand, it's starting to impact your turnaround time.
One other thing I do not understand: You have a temperature-controlled processor that can process RA-4 to Kodak's specifications, but you're opting instead to run the process at room temperature. I can think of no benefits to this approach at all. If you really want to follow Kodak's advice, process at the proper temperature and save a whole bunch of time too!
If you use the stop, the wash is not needed.
Originally Posted by FilmIs4Ever
Some vertical slot processors are temp controlled but others aren't and rely on the room temp being at least at the minimum range for room temp processing. Nova make both kinds of processor. The ones which can be set for 95F give the best of both worlds as they are quicker than a Jobo drum which requires fill and dump several times for dev, stop and blix as well as drying before the next print.
The downside to a slot processor may be that unlike B&W chems which will last several weeks in a slot processor when covered by a hollow tube on top, colour dev may need emptying and storing in a brown bottle in which air has been excluded.
I suppose that if you were doing enough prints per session then you could simply dump the dev at the end and use fresh on the next occasion.