Upgrade an Omega DII or Switch Enlargers?

[dpn]

Hi all,

I'm having a difficult time deciding how to best address a problem I'm having with my enlarger, and would appreciate input.

I have an Omega DII that I found on the side of the road. It has an Aristo cold light head that I have a love/hate relationship with. I love that prints it produces require very little spotting, but I hate its inconsistent light output. Even with its ballast heater plugged in, its inconsistent light output makes printing a real hassle. I've tried to reduce the effect of the inconsistent light output by going for long print exposure times, but inconsistency is still very frustrating. I find myself reluctant to print because of the frustration!

There is an (expensive) product that I believe will address this problem: The RHDesigns Stopclock Vario. At £379.00 shipped ($555.10 at today's exchange rate), this is not going to be a cheap fix. I hesitate to invest this much money into a very old enlarger with a very old cold light head, even though I have all the negative carriers and cones I need to print the formats I shoot.

Rather than spend a large amount of money to rehabilitate my DII, another option might be to find a Beseler 45-series enlarger on Craigslist. I've seen a few examples show up over that last year, and if I'm patient I could probably acquire one with a Dichro colorhead for ~ $200-300. This seems like a good solution, even if it means I'll have to buy new negative carriers, etc.

Are there other alternatives I'm overlooking? I've thought about trying to convert my cold light head into an LED head, but I'm not good with wiring and soldering, and I'm not sure how well LEDs would work. I don't want to go back to a normal condenser setup, because of dust and heat issues.

Thanks in advance for your indulgence in helping me work out a solution.

-- Dan

[Jon Shiu]

I would just get rid of the old cold light and move on to a dichroic 4x5 enlarger. You can probably find a Omega 4x5 with dichroic head for cheap.

I also use a DII, but prefer the condenser light source.

[Eric Biggerstaff]

http://www.modernenlargerlamps.com/M...s/Welcome.html

Excellent light source and easy to install. If the only issue is the light, then why trash an otherwise good enlarger.

[dpn]

Eric, the Model 2 looks perfect. At $349.95 plus shipping, it's definitely a cheaper solution than the RHDesigns timers. Definitely something to think about!

[Doremus Scudder]

I solved the Aristo cold-light variability by simply leaving my cold light head on for the entire printing session. After about 15 minutes (set up time for trays, etc.) the light will have stabilized. I just kept a lens cap on the lens and used a metronome for a timer, removing and replacing the lens cap as needed for focusing and exposure. This will burn out the tube faster, but mine would last 5-6 years like this. See if you can find a spare (I think Aristo will still make replacement lamps special order) and you've got 10 years of enlarging left in the old DII.

Another option would be to search for an old Zone VI stabilized cold light head or the light-sensor kit; both need either the Zone VI stabilized enlarging timer or the "Tick-Tock," a metronome timer that varies the length of the seconds dependent on light output.

Finally, will a Chromega dichroic head fit the DII? If so, or if it's an easy modification, you could just get one of them. Same diffuse light source and filtration to boot.

Best,

Doremus

[Mark Sampson]

I've used an old D-II with the zone VI stabilized cold light for many years. (It was useless without the stabilizer, as you've found.) But now it would be easier to find a D4 or D5 chassis with the super-chromega head, and for cheap; they were very pricey 25 years ago. I'm also sure you could find the parts needed to adapt the S-C head to your chassis- basically extender rods for the lifting arms. Harry Taylor at Classic Enlargers will know.

[Drew Wiley]

They're called cold lights, but are just like other fluorescent tubes and don't work well in a cold damp room. Warm up the room in advance of the printing session. Cycle the lamp on and off a bit before printing. But with regard to fluctuations in output, don't fight it. Just get some kind of light integrator that measures cumulative output rather than a nominal time. Even Zone VI made one of these probes with an attached beeper, which didn't need a stabilzer at all and will work with any cold light. Light integrators were routine in UV contact printers, so are common from used print shop gear suppliers (versus darkroom suppliers per se). But there is another kind of unevenness, and that is where a fully warmed-up lamp has bad falloff toward the bends in the tubes. This can be due to either too small a cold light to begin with (they should always be distinctly oversized relative to the film format), inefficient diffusion, or a just plain dying old tube that needs replacement. But colorheads for Omega D are so abundant and cheap that you might also consider one of these instead, if everything is in
good working condition.

[Neal Chaves]

I have been printing with cold light heads for years and found the following method works well. You need a timer with an audible metronome. After the head is warmed up, and you are ready to make a test strip, set the timer for thirty seconds. With a large black card, cover all but a one inch strip. Start the timer and count four beeps, then move the card another inch every three beeps to make a ten gradation thirty second test strip. Because the lamp burns continuously, the test strip will be very accurate. Need more time? Make a one minute strip with six second increments. The old Kodak Projection Print Scales are also good because they too are designed to run the lamp continuously. A three second burst from a cold light is only equivalent to about 1.5 seconds during a longer exposure. I use the method above with all bulbs, even the halogen bulb in my color head.

[Jim C.]

dpn, you may want to look into a Omegalite D2 cold head, it'll fit a DII and D2 omega enlargers with no modification
compared to a Chromega color head ( the lift arm rods need to be extended ) and from what limited use I have
with mine I didn't see any inconsistencies.
They do pop up from time to time on eBay.

[Bill Burk]

I've used Omegalite for years without realizing there was any visible light ring... until I scanned prints to view online. I never noticed it on any individual print but looking at prints in a computer slide show, there it was... a circle on every print.

Then I switched to an unstabilized Aristo and was happy with evenness of illumination (but it barely covers filed carrier full frame 4x5)... But I did go crazy with inconsistent print exposure.

I picked up a Zone VI stabilized Aristo, it's a joy. I don't feel it has the spectral output compatible with variable contrast paper. No problem for me, I prefer Galerie.

If I were to do it all over again, I really miss voltage stabilized incandescent light... I'd get a colorhead.