Cold Light Installation

[Dave Schneidr]

Finally decided to try a cold light after much advice from members of this forum and frustration with condensors. Ordered an Aristo for my Omega D5 and installe d tonight. Won't have a chance to print until next week now but several question s came to mind after installing. First, is there any problem caused by the fact that the cold light glows after the power is off? I should have anticipated that since it is after all a flourescent source. Does it fog paper or how do you com bat that problem? Second, do you ahve any suggestions for focusing? It seems ver y difficult to focus the greenish light, much more difficult than with the yello wish light of the tungsten bulb. Finally, a question specific to the Omega. I re moved the condensors and set the Aristo head into the can that held the fixed co ndensors. I removed the adjustable condensor and the lamp housing and fed the co rds up through the hole. When powered up I have this bright circle on the ceilin g caused by light leaking around the Aristo head. Should I add a felt strip betw een the Aristo head and the condensor can or what would you suggest.

I don't anticipate these are insurmountable problems, just not ones I anticipate d. I can't wait to get back to printing to see the glowing prints that are so ea sy to create.

[Alec Jones]

Good questions, Dave. Re: glow - just don't leave your paper out exposed to it for a long time. Focus on a substitute sheet [I use the Micromega critical focuser with no problems] and only bring out the real stuff when you are ready to expose it. By all means, mute any light coming from leaks from the "can". I have a D2 which had cracks all over the place. I used felt, held in place by velcro strips. I also have an area around the negative plane, which I covered with a drop-down "skirt". The darker you have it, the cleaner whites you'll achieve in your prints.

[pat krentz]

"Glowing prints that are so easy to create". Really? Pat

[Dave Schneidr]

"Glowing prints that are so easy to create". Really? Pat

Well, that's what the cold light proponents would lead you to believe. My expectation is somewhat more realistic. I'm hoping for more even illumination than my old scratched and chipped condensors are producing and possibly better tonal gradation in the highlights.

[Charlie Stracl]

Well, your cold light should help compared to chipped and cracked condensors. I got a Saudners/LPL diffuse light enlarger 'cause I couldn't easily focus & compose with my Zone VI enlarger light source, so I sympathize with you there.

[Brian Ellis]

I've used an Aristo VCL head for quite a while (six years) and have never observed any "glow." After reading your message I checked by looking up through the lens and still saw no glow. Is this something you've seen or are you just expecting that it will occur? Although normal household flourescent lights do glow for a while after turn off, the Aristo light is, as you know, colored and I wouldn't think it would glow like a household light. I'd call Aristo and ask whether it's normal. The guy who runs the company (sorry, I forget his name) has been very helpful to me with several questions over the years. I don't own an Omega but my Beseler had various light leaks both through the power cord that runs into the top of my Aristo head and around the negative stage. I fashioned a cardboard box-like thing out of a shoe box that fits over the head and has sides that cover the negative stage. It prevents any light leaks and has the added bonus of hopeuflly minimizing dust in the head. Of course you have to take it on and off when putting the negative carrier in or removing it but that's very simple since it's just light cardboard and isn't attached to the head in any way. I've also used electrical tape to stop other light leaks.

[Doug Paramore]

Dave: I have never observed the afterglow with my ol' Aristo cold light head, but maybe it's there. Anyway, it doesn't effect exposure. You will notice that it is a lot easier to get detail in the highlights with the cold light or a diffuser head. And yes, the whites do seem to glow when printed with the cold light head, at least mine do. It is not a magic wand for good prints, but a great tool. I have made comparison prints and there is a difference.

Regards,

[Dave Schneidr]

I noticed the glow when looking directly at the light after it had been turned off. I don't yet know if I would see any light on the easel. I discovered the glow when sealing the light leaks around the housing.

[Dave Schneidr]

I think I may have discovered the source of the glow. My Gralab 451 timer apparently has some voltage present at the outputs even when off. I discovered this when I tried an interposing relay between the timer and the cold light. My relay buzzed even when de-energized. With the relay in place I don't see the glow, however. Is my 451 timer not working correctly or is it not suited to the cold light. It is listed as capable of a 1/3 HP motor load.

[Charlie Stracl]

Dave,

I am in awe of how these answers go.

I don't think there should be any residual voltage on your timer in the off state, except maybe for a volt or two. Certainly not enough to make a relay buzz. Contact GraLab and get a real answer.

DIMCO-GRAY 8200 South Suburban Road / Dayton, Ohio 45458 937-433-7600 / FAX: 937-433-0520 1-800-876-8353