 |
 |
Go To:
(Kodak RA-4, Tetenal Professional PK, and Tetenal Mono PK)
Recommended Process for Kodak RA-4, Tetenal Professional PK:
- Rotation Speed (with reversing directions) 'P'/75 for 1500 and 2800 drums, '4'/50 for 3000 drums
- Temperature 35°C (95°F)
- Pre-Rinse 0:30
- Developer 1:00
- Stop-Bath 0:30
- Rinse 0:30
- Bleach-Fix 1:00
- Final Rinse 1:30 (3x 0:30)
- Dry As needed
Recommended Process for Tetenal Mono PK:
- Rotation Speed (with reversing directions) 'P'/75 for 1500 and 2800 drums, '4'/50 for 3000 drums
- Temperature 20°C (68°F)
- Pre-Rinse 0:30
- Developer 1:15
- Stop-Bath 0:30
- Rinse 0:30
- Bleach-Fix 1:00
- Final Rinse 3:00 (6x 0:30)
- Dry As needed
Pre-Rinse
The drum and paper are brought to the process temperature. The emulsion is completely soaked with water.Developer
Contrast and density are determined by development.Stop-Bath
The stop-bath ceases the development and prepares the paper for the bleach-fix. For some RA-4 type processes this step is not necessary. It will not harm the process if used.Rinse
The rinse removes the stop-bath (or developer, if used without stop-bath). For some RA-4 type processes this step is not necessary. It will not harm the print or process results if used.Bleach-Fix
In this step the silver and silver salts are removed from the paper.Rinse
The rinse washes out the remaining chemicals. Rinse for at least one and a half minutes (three or more changes of water).Dry
As needed.
Stop-bath is not supplied with most color print chemical kits. You may use Kodak Indicator Stop-Bath, or any common black and white process stop-bath. You may mix your own by diluting acetic acid to about a 2% solution. Stop-baths with indicators in them (yellow color) will not stain the print. Acetic acid (28%) diluted at a ratio of 1 part acid to 20 parts water will make a 2% solution.
The last rinse should be broken into thirty-second segments. Use a complete change of rinse water at each segment. The number of water changes is more important than the time of each segment. You may rinse longer (up to five minutes) without harming the processing. However, there is no benefit to extending the rinse times, or number of segments, beyond the recommendations.
RA-4 solution quantity: Kodak suggests using a minimum of 110 ml of developer per square foot of paper, or 61 ml per 8x10" print. The resulting quantity is greater than specified on the JOBO drums.
The revised quantities for JOBO Print Drums (filled to capacity with paper) are:
- Drum # 1526 61 ml minimum (1 8 x 10" print)
- Drum # 2830 122 ml minimum (2 8 x 10" prints)
- Drum # 2840 122 ml minimum (2 8 x 10" prints or 1 11 x 14" print)
- Drum # 2850 244 ml minimum (4 8 x 10" prints or 1 16 x 20" print)
- Drum # 3062 244 ml minimum (3 8 x 10" prints or 2 11 x 14" prints)
- Drum # 3063 366 ml minimum (6 8 x 10" prints or 1 20 x 24" print)
With RA-4 processes, you may use a greater volume of chemicals than the minimum recommendations. More than the recommended amount of chemicals is safe, and will not affect the process times.
All modern color process bleach or bleach-fix chemicals (with the exception of Ilfochrome bleach) requires oxygenation (exposure to oxygen) to perform its function properly and completely. Unlike developer or other chemicals, you should intentionally introduce air (with its oxygen) to the bleach or bleach-fix. Oxygenation is most easily accomplished while diluting the stock solution. Place the bleach or bleach-fix in a larger (about twice the volume of the mixed solution) sealable container. Seal the container and shake vigorously for about thirty seconds. For situations where this procedure is not practical, an inexpensive aquarium 'bubbler' may be used to aerate the solution. Leave the bubbler on for about a half hour. If the bleach or bleach-fix has not been aerated for a week or longer, repeat the procedure before using the chemical.
As with all color prints, do not attempt to make any judgment of the colors while the print is wet. Color can only be judged correctly when the print is dry.
It is good practice to be consistent in processing procedures. However, it may be useful to know that with the exception of the developer, all steps in the RA-4 process are 'taken to completion.' That is, once the action of the chemical or rinse has done what it is supposed to (had its effect), further time in the bath or rinse will have no additional benefit or harm. If you are to err in the timing of the process steps other than the developer, it is safer to go longer, not shorter. Be aware however, that very long (over 20 minutes) immersion times in any solution or water could cause frilling or discoloration at the edge of the paper and other problems, and should be avoided.
Caution: You must use RA-4 type chemicals for RA-4 type paper. Be sure that your paper and chemicals are compatible.
If you have any questions, contact us utilizing one of the following methods:
Equipment or Processing Questions:
- Phone: Customer Service Department (734) 205-9421
e-mail: tech@jobo-usa.comRepair Questions:
- Phone: Repair Department (734) 205-9420
- e-mail: repair@jobo-usa.com
JOBO Contacts
- Telephone (734) 677-6989
- Fax: (734) 677-6963
- Postal address
- P.O. Box 3721, Ann Arbor, MI 48106
- Shipping Address
- 4401 Varsity Drive, Suite D, Ann Arbor, MI 48108
- Electronic mail
- Sales: sales@jobo-usa.com
- Equipment & Processing Questions: tech@jobo-usa.com
Repair Information: repair@jobo-usa.com- Shipping or Billing Questions: help@jobo-usa.com
Webmaster: webmaster@jobo-usa.com
Send mail to webmaster@jobo-usa.com with questions or comments about this web site. Copyright © 1997-2005 JOBO Fototechnic, Inc. All rights reserved. Information in this document is subject to change without notice. Other products and companies referred to herein are trademarks or registered trademarks of their respective companies or mark holders. Copyright to all of the photographs displayed on this site is owned by each of the photographers. You may not sell, publish, license or otherwise distribute any photographs without the written permission of the photographer.
This page last updated on 03/20/02