Beseler Minolta 45A for Color Separation?

Hi all,

Working my way towards fully analog colour carbon printing (yes, I know ) and looking at enlarger options for creating separation inter negatives / positives from slide and negative colour film. Reading the Kodak Color Darkroom Dataguide, I came across RGB enlargers and got me thinking if these were better options for creating Red, Green and Blue separations vs using a dichroic head with RGB filters. My thinking is that it would give me better separations and more control when balancing colour and possibly creating masks.

I wasn't able to find much information online as it seems these are rare systems (but some available to buy used). Is this a hard pass or worth pursuing as a better option for what I am trying to accomplish?

I know nothing about the process you are working on but I own one of those heads. I was very excited to use it when I opened my darkroom last month, but sadly I think the bulbs need to all be replaced and that is very difficult to do as they are not manufactured any longer to the best of my knowledge. So I have sadly given up on that head. You may be better off with another option.

Jay Schrotenboer said:

I know nothing about the process you are working on but I own one of those heads. I was very excited to use it when I opened my darkroom last month, but sadly I think the bulbs need to all be replaced and that is very difficult to do as they are not manufactured any longer to the best of my knowledge. So I have sadly given up on that head. You may be better off with another option.

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I have noticed that the bulbs aren't being made but I did see some for sale (brief ebay search) so I just assumed it was reasonably easy to come by. I also assumed that I wouldn't need to change bulbs that often because my volume of prints would be pretty low compared to the printing volume of a serious 80s-90s darkroom that these were designed for.

I have a 45A with spare tubes. The filters under the tubes all seem to be separation quality as far as bandpass. Since the tubes are xenon flashtubes if the original stock is not available I would think you could find a set with similar specs and adapt the mounts to get by. I quite using mine because the light output wasnt enough for the b&w paper I was using at the time.

the 45a was used in sep mode to expose to Kodak Pan Matrix film. I owned several
I wouldn't buy one today -- they provided a great convenience for match color requests; no one does that now.
Without much experience, this machine would be a tough mask maker. The 45a isn't the system I'd start with to make sep positives/negatives.

However, something to review:

glbeas said:

I have a 45A with spare tubes. The filters under the tubes all seem to be separation quality as far as bandpass. Since the tubes are xenon flashtubes if the original stock is not available I would think you could find a set with similar specs and adapt the mounts to get by. I quite using mine because the light output wasnt enough for the b&w paper I was using at the time.

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I wonder if any of these would suffice? I have a 45A I have not yet put into use and the lack of tubes makes me nervous.

https://www.xenonflashtubes.com/linear-flash-lamps_11

Thank you! Probably not something I would add to the mountain of problems carbon printing bring with it. Sounds like an interesting curiosity to play around with though, so may get one if the opportunity arises just to mess with. I do appreciate 80s tech that tried to push the envelope and until today, I had no idea something like this even existed.

Seems like it would be an excellent solution, as you would not need to continuously move the filters all the way in and all the way out of light path, as in most other enlargers. You would also not need to risk bumping the enlarger while changing under-the lens RGB filters.

That was my initial thoughts but the manual excerpt posted by sasah zib points to a temperamental system, e.g. "the B45A will shut itself down". The full manual can be found here https://www.photrio.com/forum/threads/besler-minolta-45a-manual.163508/. It would probably wiser to use an LED system instead (diy, Intrepid, or Heiland) to get the same benefits without the maintenance factor.

Kino said:

I wonder if any of these would suffice? I have a 45A I have not yet put into use and the lack of tubes makes me nervous.

https://www.xenonflashtubes.com/linear-flash-lamps_11

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If someone knows or finds out if there is a reasonable priced replacement for the flash tubes I know that I would be extremely interested. I would like to try actually printing with this head as is looks and sounds very cool. I only managed to make my first ever test strip and then it stoped working. Luckily I had another head to use in its place.

temp isnt significant in your probably low use. focusing time was the big failure point of these boxes.

REMINDER
what you are attempting was done for 40 years without such equipment; the 45a solved the SLIDE print problem more than the sep one (one easily and readily solved by other means)

Paul Outerbridge used this as type of equipment:
His emphasis was on picture driving process. That meter was also his studio meter.
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Yes I agree, fancy equipment isn't a must for a 100+ year old process. It came up because I am getting my first proper enlarger (I currently use my 4x5 camera mounted on a wall bracket to make prints); so figure if there was something purpose built that can help me with my goal why not check it out, but I don't think this system is for me.

45A not a good idea. The flash tubes expose by means of cumulative exposure, and the short durations ideally needed for film color separations would just have too much variable flickering. There was a far better and later Beseler RGB additive colorhead called the Beseler Universal (don't confuse this with the other three dozen items Beseler labeled as "Universal") can potentially be the cat's meow IF you find one which has the electronics working properly already. Getting the control panel or power supply fixed can cost you a bundle. Beseler themselves orphaned all these a long time ago.

I suspect that a lot of these folks trying to convince you to do it the way Outerbridge and other earlier folks did has never tried it themselves. Nearly everyone doing color carbon printing these days is having the separations generated digitally after scans. Yes, it can be precisely done in the darkroom using pan films like TMX100 or FP4 within available film size ranges. But expect to spend a lot of time getting everything balanced. And that's in a best case scenario using a predictable modern colorhead. And yes, true RGB would be nice. But I've personally run tests direct narrow-band RGB right out of the additive head, versus "white light" out of the colorhead separated with glass 29 red, 61 green, and 47B blue filters below the lens, and the densitometer-plotted results were almost identical. But pick one or the other method, or you'll go nuts like me. I also figured out the correct balance for RGB in-camera separation using TMax. Don't know why. Just an itch. I'll never have time to actually print color carbon.

LED ????? Take your chances. Trying to find anything narrow-band cutoff at the correct wavelengths in that category is wishful thinking. The less squirrelly variables, the better.

You do have at least a black-and-white transmission densitometer? Life can be hell without one of those.

One thing about the control module is it can crash, and theres a tiny hole in the middle of the front thats a switch you can toggle with a pin to reset it and bring it back to life.

The control modules are very sensitive to unexpected voltage spikes or EMI (electromagnetic interference). During a lightning storm or if there is utility line work going on, you not only want to turn them off, but unplug even the extension cord. If things go schizophrenic inside the panel, it might instantly reset or take a couple weeks or more to correctly do so, depending. Some were no good right out of the box - defective triacs I suspect. So a very nice system to have, yes, especially if you have an advanced degree in Enlarger Psychiatry.

Thanks @DREW WILEY I am taking it very slowly and step by step, enjoying the process rather than getting somewhere in particular. My approach is really just acquiring tools (if needed) to solve problems as I encounter them rather than being too anticipatory, though I do need an enlarger as my current system of using my 4x5 camera doesn't give me good consistency (having to set it up every time). As for control modules and EMI - hard pass; I'll just get a regular dichroic .