Tabletop RA4 processors

[DREW WILEY]

Roller machines are really best for convenience at substantial volume. More chem involved and more potential maintenance, possibly more
fumes to contend with, depending on your setup. With drums you do need to be a little more conscious of ambient air temperature, fill and drain time, and esp the temp of the developer INSIDE the drum during the duration of actual development. But all easily doable if you control
the variable one by one. If prefer drums because I can use them outdoors in mild weather to minimize overall chem exposure. For the same
reason I would never ever personally use trays of slot processors. I have a nice roll transport machine, but have never even plugged it in yet!

 

[mtjade2007]

I have a RCP20 that I have converted many times. I once converted it for C-41 processing. The first bath become about 3 minutes and something like 10 -20 seconds. But I never really used it in processing C-41 negatives. I then reconverted it to RA-4. The first bath became about 45 seconds. That was a little long but I could adjust the processing temperature lower to compensate it. Again I never used it for RA-4 processing. I guess I just did the conversions to see if it could be done. I just tried the plastic gears that I could find and tried them. I was able to covert it from the original 2 minutes first bath to either 45 seconds or to 3+ minutes. It was quite easy. The toothed belt was not changed. Only the gears were swapped.

 

[fotch]

My RCP20 has been packed away for the last 20+ years...I wonder if the foam rollers are still good. I only used it when I had a lot of color printing to do and it was great. For fewer prints, would use my Jobo.

 

[markd514]

For anyone still interested in RA-4, trays and drums might suffice but if true color correction is important to you (and it should be), it ain't going to happen without a roller transport machine.

i don't think I agree with that. I get perfect prints in a drum at room temp and even let the dev and blix go one minute longer as a test with no shockingly different results. Practically identical

 

[DREW WILEY]

The ability of drums to maintain temp inside them is related to several factors, including the solution volume, the type of plastic involved,
the duration of the processing step, the difference between liquid and ambient temperature, etc etc. But if you understand how these various
factors interact, and start with the correct temp chem, it's easy to maintain precise process temps.

 

[markd514]

The ability of drums to maintain temp inside them is related to several factors, including the solution volume, the type of plastic involved,
the duration of the processing step, the difference between liquid and ambient temperature, etc etc. But if you understand how these various
factors interact, and start with the correct temp chem, it's easy to maintain precise process temps.

I alter my prewash temp to make sure my developer temperature at the end of the cycle is still very close to what it was before it went into the drum.

 

[frotog]

i don't think I agree with that. I get perfect prints in a drum at room temp and even let the dev and blix go one minute longer as a test with no shockingly different results. Practically identical

"Practically identical" is not good enough.

Challenge: Try making two identical prints this way, as if you're printing an edition. By identical, I mean that you should not see even a 1/2 cc color difference between the two of them.

With drums, it's not going to happen. If you think it is, scan your results and let us be the judge. Anything less is just hot air.

 

[fotch]

If your making a lot of prints, a drum is insane. Doing 30+ 8x10 is easy in a processor. Like wise, doing just a few prints is easier in a drum system. It takes longer to empty & clean the processor, as used in a home darkroom.

 

[markd514]

"Practically identical" is not good enough.

Challenge: Try making two identical prints this way, as if you're printing an edition. By identical, I mean that you should not see even a 1/2 cc color difference between the two of them.

With drums, it's not going to happen. If you think it is, scan your results and let us be the judge. Anything less is just hot air.

Ok, I guarantee i can get 2 identical prints by drum. Practically means that I could not tell any difference, so I went with the easier process.

 

[DREW WILEY]

In my case, what is more important, volume of convenience or health? Someone outright offered me free a nearly mint 50" Kreonite, and I
even have the space and wiring for it. But that's a heckuva lot of chemistry on a routine basis, and one has to have the print volume to warrant it in the first place. With big drums I can just mix enough chem for the test strips and one-shot real-deal, load the print in the drum
in the dark, and process the whole thing on my portable roller cart outdoors (in mild weather). Maybe I'll keep my little 20" roller transport
processor, cause it runs on 110V and could be temporarily installed in a little dedicated dark shed, where any fumes wouldn't get into my
main dkrm facility. At this point in life I have no interest in another seriously building. A couple big RA4 prints a week is plenty for me. In
cold weather I do mostly black and white printing anyway.

 

[Wayne]

I don't think 11 out of 10 people could detect a 1/2 cc difference

 

[frotog]

Ok, I guarantee i can get 2 identical prints by drum. Practically means that I could not tell any difference, so I went with the easier process.

Wishful thinking. But then again, it's easy to call your bluff having worked as a professional RA-4 printer during the medium's heyday. There's a reason RT machines hold temp to tolerances of +/- .25 degree f. and time/agitation to +/-.5%.

"I don't think 11 out of 10 people could detect a 1/2 cc difference"

I'm always surprised when I read comments like this in these color printing threads. Tweaking prints down to 1/2 cc is what color printers do - their livelihood depends on it. It's not just artists but the entire print industry - editors, art directors, photographers, etc. - obviously color is critical to them. Most often you are working with a suite of images. The color balance print to print has got to be consistent. When it's even a bit off, it's glaringly obvious. Even the assistant picking up the job will be able to see it. Your name will be mud. This is what separates the pros from the students (never mind the enthusiast in his home darkroom).

I suppose the "its close enough" attitude towards color reproduction and the unwillingness to fully understand the capacity and functionality of current color materials also explains why so few hobbyists here can see a difference between the old fuji cut sheet product and the current crystal archive ii, never mind the problems associated with the fact that all these papers are optimized for digital exposure.

When your demands fall far short of what the medium is capable of it's also no wonder that sub-standard processes seem "just as good" as the industry gold standard. Though your observation, in this case, can hardly be regarded as true opinion.

 

[DREW WILEY]

zzzz.... Here we go again. Well, my own color standards are far more nitpicky than any big pro color lab I have ever dealt with; and there
were some exceptionally well equipped labs in this area who made a religion out of control strips. Yes, that worked reliably. But so do drums if you understand them. Sure, I could install a serious large industrial processor if I wanted to. But I have no interest in that kind of volume. Normal human vision has problems resolving more than 2cc. I did a lot of pro color work using pigments for a long time, so can detect about 1cc distinctions. That ability is related to training more than physiology. I wonder how many color densitometers even have that kind of accuracy. Sure, they are nice for seeing thru the orange mask on a color neg, but so is a well engineered color target and
test print IF you understand how those are likewise designed.

 

[DREW WILEY]

Oh... and I do have a fancy thermoregulator system for the water bath that maintains temp INSIDE 1/10th deg F. I use it for very fussy things like matched color separations. It's ridiculous overkill for RA4, so no need there.

 

[DREW WILEY]

... More... It's pretty obvious that for multiple prints, esp in big sizes, a properly equipped pro lab has a distinct advantage. After all, that's
their niche. At one time big expensive automated drum processors existed too, but due to the greater convenience of roller-transport machines, fancy drums tended to get relegated to subsidiary processes like "R" prints (now extinct), or were converted to Ciba P-3. Any roller-transport machine actually built for Ciba was horrendously expensive to buy and maintain because this was so corrosive; but labs used them too, independently of RA4 lines. What I don't get in this particular debate if why any pro lab would fear "amateurs" tinkering in RA4, or even doing it extremely well. The more people encounter the qualitative distinction between RA4 prints (whether optically enlarged or laser-generated) and inkjet, the more it would seem to help every one. Not many people are ever going to have their own color darkroom, esp for large prints or serial work. Pointing out the current potential of chromogenic prints by a general interest in this medium,
in terms of real prints, would seem a far wiser tack than trying to undermine individual use of it. Labs still provide a lot of special services that it's simply unaffordable for the home darkroom worker to get involved with, including all the post-process mounting of big prints etc.
Going around saying, "bad dog, bad dog" every time someone tries to generate interest in RA4 is pretty much equates to saying, "just go make inkjet prints instead, and forget the whole thing!"

 

[frotog]

Oops... I forgot one caveat in my last comment and it appears as though I touched a nerve as a result. So, without further ado I humbly offer this much needed addendum... DREW WILEY is the obvious exception to the rule (any rule) because he's the BEST PRINTER IN THE WORLD, though sadly this accolade has only been acknowledged by him and him alone since the rest of the world are PHILISTINES who've sold their souls to ADOBE and who in the process have lost all CRITICAL ABILITY to judge his GREAT WORKS (of which there are many).

There, there, it's OK Drew - go back to your cubicle now, your role as a plastic-drum-processing analogue apologist has been avenged.

 

[DREW WILEY]

My mistake for not logging in first... A certain individual has been on "ignore" for some time due to a pattern of gross misinformation and
personal slander.

 

[DREW WILEY]

If this guy is legit I don't understand why he won't simply tell us the name and location of his Lab, so the alleged level of service can be verified ...

 

[mtjade2007]

"Practically identical" is not good enough.

Challenge: Try making two identical prints this way, as if you're printing an edition. By identical, I mean that you should not see even a 1/2 cc color difference between the two of them.

With drums, it's not going to happen. If you think it is, scan your results and let us be the judge. Anything less is just hot air.

Have you used a Jobo ATL processor? You can get identical prints even if you want to print a hundred prints. You can get identical prints on any other day too. On the other hand not all roller transport processors can print identical prints even printing only a few. It depends on if you can replenish accurately controlled electronically. If you go away and come back a week later you may not be able to get identical prints any more unless of course you always dump the chemicals and start with fresh every time, which is never the case.

The real difference between the roller transport and drum processors is in productivity. The roller transport machines need highly precise replenishment not likely done manually or it can be an inferior processor than drum processors such as Jobo ATL processors.

 

[AgX]

The roller transport machines need highly precise replenishment not likely done manually or it can be an inferior processor than drum processors such as Jobo ATL processors.

For each sheet you will need a certain volume of replenisher. With the right laboratory measuring devices you could do that quite easily on a roller-transport processsor lacking automated replenishing.

 

[mtjade2007]

For each sheet you will need a certain volume of replenisher. With the right laboratory measuring devices you could do that quite easily on a roller-transport processsor lacking automated replenishing.

Yes, but only with accurate replenishing which is not as easy as one might think. Take RCP-20 and the color developer as an example. The developer get's consumed by the paper, by natural oxidation and also by vaporization of water content due to heating. So going through a run in a couple of hours and by a few says will likely require different replenishing schemes.

The replenishing is done by draining a right amount of developer first. This is not as trivial as one might think. Sometimes you may drain too much or too little. Keep in mind there are no valves on the draining pipes. You will need to wear vinyl gloves if you don't want to get in contact with the developer. You will need to pour a right amount of fresh developer into the developer bath. You will need to top it up to the right level. You will need to wait for it to reach the right temperature before you can process the next sheet. You will also need to keep the partially emptied bottle of developer (with fresh developer waiting to be used) from getting oxidized. Don't forget you will need to do the same to the blix as well. The stop bath in the middle needs to be replenished too. So it is not a simple task if you can only do it manually. I have done it and I can tell you it's not fun. If I remember correctly the RCP takes about 2 liters of juice to fill up the developer bath and same amount for the blix. If the developer does not get replenished it will take only a few prints to start getting color shifts. You will find it taking a lot more time and effort to replenish the thing than exposing the paper under an enlarger.

Believe me I loved and hated the RCP-20 back then. I am yet to figure out what to use it for in the future. I have a complete optical darkroom being idle right now. I have all formats of film carriers for my dichroic head enlarger. Meanwhile I am very happy with my ATL-2300, my Minolta MF film scanner and my Epson R2880 printer.

 

[EdSawyer]

Fujimoto CP series print processors have a nice automated replenishment setup. Very handy.

 

[AgX]

The replenishing is done by draining a right amount of developer first. This is not as trivial as one might think. Sometimes you may drain too much or too little. Keep in mind there are no valves on the draining pipes. You will need to wear vinyl gloves if you don't want to get in contact with the developer. You will need to pour a right amount of fresh developer into the developer bath.

A well designed overflow and a decent measuring device would enable to do the replenishing within a few seconds per bath.

 

[mtjade2007]

A well designed overflow and a decent measuring device would enable to do the replenishing within a few seconds per bath.

RCP-20 tanks are normally filled with something like 2 liters of working solutions. The tanks are not all the way filled up. If overfilled contamination of one fluid from another will occur. The tanks do not have any overflow passage for the fluid to overflow. There are only 3 holes at the bottom of the tanks attached with 3 rubber hoses for draining. Everything is so simple. So yes, you could design and fabricate an overflow mechanism and a refilling device with precision measurement for accurate draining and refilling. Keep in mind that the amount of fluid to refill does not equal to the amount to overflow or to drain. There is constant loss of fluid by carrying over and vaporization. So it will not be trivial to figure out an accurate replenishing scheme. You will always need to fill more than the amount to drain.

By the way the workflow of a home darkroom optical color printing will be extremely slow. There is always one to two test prints done to figure out the correct filtration and exposure. If you are lucky you may hit it right on the money on your first print development. Don't expect to be able to crank out many prints on an evening or even on a day. The RCP-20 will likely to be rolling and rolling most of the time without actually processing anything. It doesn't take long for the house to be full of the chemical smell and yet not actually processing anything.

I think for black and white paper processing at room temperature you will not have to let the processor rolling all the time to keep up with the temperature. You can turn it on only when you are ready to process a print. But you can do it in a try which is even easier.

If you can fabricate a replenishing device that by one press of a button and everything is automatically done that will be perfect. I guess I figured it out long time ago a Jobo would be a lot easier for me. It makes a lot more sense for a home processing situation.

 

[fotch]

I did 25 8x10 color prints of a VIP portrait and there were no color shifts between any of the prints. After I adjust for the right filter pack, I just cranked out all the prints. Never had an odor problem although my darkroom was set up in a corner of a larger room, about 2ox25ft. The prints were identical. Its been about 30 years so I may have forgot some details like replenishing but I don't recall doing that. YMMV