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Photo Forum / Film Photography / Darkroom / March 2005true B&W roller transport processing
I have a 20 inch Colenta RA4 roller transport processor. I'm interested in setting it up to process black and white prints. Can this be done? Are there chems out there for this type of work? Thanks, Eric I tried this with my Durst Printo -- you can change the cogs to various processing speeds -- Ilford had a white-paper on using more concentrated fix solutions and shorter processing times. My experience was that it "worked", but I thought using trays to be more economic. To really get the maximum black out of a print it seems to take 2 minutes of development time. At least with the roller processor you can maintain a constant temperature. > I have a 20 inch Colenta RA4 roller transport processor. I'm interested > in setting it up to process black and white prints. Can this be done? [quoted text clipped - 3 lines] > > Eric > I tried this with my Durst Printo -- you can change the cogs to various > processing speeds -- Ilford had a white-paper on using more [quoted text clipped - 6 lines] > At least with the roller processor you can maintain a constant > temperature. I maintain a constant temperature for Black and White prints by allowing the overflow from my Zone VI print washer to overflow into my preliminary washing sink. From there, it overflows into my processing sink where my 5 trays are. No extra water required for these constant temperature baths.  Signature.~. Jean-David Beyer Registered Linux User 85642. /V\ PGP-Key: 9A2FC99A Registered Machine 241939. /( )\ Shrewsbury, New Jersey http://counter.li.org ^^-^^ 08:10:01 up 42 days, 16:27, 3 users, load average: 1.33, 1.17, 1.07 > > I tried this with my Durst Printo -- you can change the cogs to various > > processing speeds -- Ilford had a white-paper on using more [quoted text clipped - 11 lines] > washing sink. From there, it overflows into my processing sink where my 5 > trays are. No extra water required for these constant temperature baths. Let me chime in with my ignorance--what does the difference in temps mean to print developing? I carefully control my film development temps, but pretty much let the trays fall wherever (usually 65-75 degrees, over the course of a year). I'm not having any problems, per se, but I'm a pretty casual dark room user at this point. Thanks SignatureRegards, Matt Clara www.mattclara.com > Let me chime in with my ignorance--what does the difference in temps mean to > print developing? I carefully control my film development temps, but pretty > much let the trays fall wherever (usually 65-75 degrees, over the course of > a year). I'm not having any problems, per se, but I'm a pretty casual dark > room user at this point. > Thanks The way I print, it matters little what the actual temperature is, though my processing temperatures are never less than about 75F. What does matter is that the temperature for a given day not change too rapidly, and keeping my trays in a sink with the wash water overflow (supplied by a temperature regulating valve) has enough thermal mass that the temperatures cannot change rapidly. The reason it matters little is that I always develop for the same time (2 minutes for D-72 1+2, 3 minutes for Ansco 113 -amidol), and adjust exposure of the print so the maximum black is produced. So the exposure of a print is implicitly calibrated for the developer temperature. The temperatures for the other baths do not matter much, provided they not get too cold, where the fixing might not work fast enough. It happens that all my baths are within 1F, but with papers hardened, this is probably of much less concern than with old unhardened films (if you can even get those anymore). Signature.~. Jean-David Beyer Registered Linux User 85642. /V\ PGP-Key: 9A2FC99A Registered Machine 241939. /( )\ Shrewsbury, New Jersey http://counter.li.org ^^-^^ 10:25:00 up 42 days, 18:42, 5 users, load average: 1.15, 1.06, 1.01 > Let me chime in with my ignorance--what does the difference in temps mean > to > print developing? I agree. Print developing is pretty much a completion process. 2 1/2 minutes of Dektol 1:2 does the trick. Several seconds on either side is for the annals to worry about. "Eric Palmer" <BlackcrownEP@gmail.com> wrote in message > > I have a 20 inch Colenta RA4 roller transport processor. I'm interested > > in setting it up to process black and white prints. Can this be done? > > Are there chems out there for this type of work? There is (was?) a technique called 'stabilization processing'. It used a cheap 2 bath processor and delivered a damp print in ~15 seconds. Popular with newspapers in the old days. Prints faded in a month or so unless washed. Max black was a dark muddy grey. Ditto max white. There are 'Rapid RC' papers that have developer incorporated into the emulsion and develop in under 30 seconds. As usual: Google knows. SignatureNicholas O. Lindan, Cleveland, Ohio Consulting Engineer: Electronics; Informatics; Photonics. To reply, remove spaces: n o lindan at ix . netcom . com psst.. want to buy an f-stop timer? nolindan.com/da/fstop/ > "Eric Palmer" <BlackcrownEP@gmail.com> wrote in message > [quoted text clipped - 6 lines] > with newspapers in the old days. Prints faded in a month or so unless > washed. Actually, they would deteriorate even faster if washed. They needed to be fixed and washed to preserve them longer. If not fixed and washed, they had to be kept separate from conventional prints as the residual fixing agents in the paper would seriously contaminate any surface with which they came in contact. > Max black was a dark muddy grey. Ditto max white. > > There are 'Rapid RC' papers that have developer incorporated into > the emulsion and develop in under 30 seconds. > > As usual: Google knows. Signature.~. Jean-David Beyer Registered Linux User 85642. /V\ PGP-Key: 9A2FC99A Registered Machine 241939. /( )\ Shrewsbury, New Jersey http://counter.li.org ^^-^^ 10:30:00 up 42 days, 18:47, 5 users, load average: 1.10, 1.08, 1.02 > I have a 20 inch Colenta RA4 roller transport processor. I'm interested > in setting it up to process black and white prints. Can this be done? > Are there chems out there for this type of work? How many baths on the processor? Agfa Multicontrast I think is intended for machine use. RA-4 is 45 seconds for dev and blix. Agfa Multicontrast with RC paper is 60 seconds at normal B&W temps. I forget how fast rapid fix is but you could always finish fixing in a tray. Nick > How many baths on the processor? > [quoted text clipped - 4 lines] > > Nick Three bath tanks. I'm just wondering if I'm over looking something. I plan on slowing the dev time to 120 sec and keeping the temp around 21 Celsius. Does anyone know what the replenisment setting might be like? Should the drying time be a concern? Is there a big difference in drying times for B&W RC paper and RA4 paper? Thanks for the replys, Eric > > How many baths on the processor? > > [quoted text clipped - 17 lines] > > Eric When I'm printing B&W RC paper, I keep the prints in a water holding bath until I'm done. Then I go into the next room, fire up the old Hope Minilab, and run the prints thru the wash racks twice. The second time thru, I let the prints go on into the dryer rack. There appears to be no real difference in drying between B&W and RA4 RC paper. As for replenishment, that would depend on your chemistry and machine. For my processor, a replenishment cycle hits every 160 square inches of paper. I set the metering pumps so that the proper amount of replenisher(s) are pumped in at each cycle. (When using the machine just for washing prints, replenishment is not an issue; only water flow rate.) My question to the OP would be do you process sufficient B&W to provide a tank turnover before the chemistry goes sour? If, for example (these figures are pulled from thin air!), the replenishment is 10mL per 8x10 and the developer tamk holds 10L, than 1000 8x10's will have to processed for a tank turnover. If the tank (working) developer has a life of 4 weeks, you need to process an average of 250 8x10's a week. This assumes that you don't dump the chemicals after use. Ken Hart I did this for years where I worked using an old Pako film processor, Developer was Kodak PolyMax RT (I think--made for the Kodak Roller Transport) and fix was Kodak Rapid fix at Dilution for film but without hardener so that it would wash out faster, paper was Ilford Multigrade RC (III I think on 3.5" and 5" rolls) and I taped scrap film to the beginnings of the rolls to use as leaders since this machine would not process paper with out a guide card. I would suggest you stay away from developers like Dektol that leave a lot of crud buildup in trays. > I have a 20 inch Colenta RA4 roller transport processor. I'm interested > in setting it up to process black and white prints. Can this be done? [quoted text clipped - 3 lines] > > Eric Eric, this is so easy to do, but most people don't bother trying. You can run any B&W RC paper in this processor without making any changes to the RA-4 specs. 45 seconds at 35C is fine for most B&W papers, maybe a little longer than needed for the developer incorporated papers, but fine. Use chemicals designed for replenished processing systems, such as Kodak Polymax RT Developer Replenisher, and either Polymax RT Fixer, or Rapid Fixer mixed 1:3 with no Part B (hardener). Using tray developers like Dektol, Polymax T, or D-72 will allow too much silver and dirt to build up on the rollers. Machine developers like Polymax RT have additives which help maintain a clean processor. Replenishment rates of about 20 mL/ft2 for developer and 30 mL/ft2 for fixer will work well. Good luck and enjoy the easier work in the darkroom. >I have a 20 inch Colenta RA4 roller transport processor. I'm interested > in setting it up to process black and white prints. Can this be done? [quoted text clipped - 3 lines] > > Eric |
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