why white paint inside Omega cold light?

[eli griggs]

I just discovered that the lower hemisphere of my E6 Omega cold light (circle light bulb) has been painted white and it looks like an user modification. The upper half of the head has a white (off white) enamel.

As the paint is separating from the smooth finished aluminum housing and flaking is some areas I want to remove it. Before I do I'd like to know, is this a common hack and if so, is there any real advantage to it?

Cheers

 

[MarkS]

Presumably to the idea was to get the most possible light out of the unit. The upper part is probably "off-white" because it has yellowed over the decades. I found the D-size version to be such a pain that I threw it away and replaced it with a Zone VI cold light with stabilizer. Not an option for 5x7, I realize.

 

[eli griggs]

Thanks Mark, you're correct that the upper is yellowed somewhat. I can see why the previous owner might have though white paint would soften the light but the bare aluminum is so much more effective at reflecting light back up to the dome top that I think I'll be better off removing it.

Could it be that he found the light too hard for portraits and so tried an adjustment? I ask this because of the very many negative holders, masks and templets I was given with this darkroom gear. There must be about three dozen card stock portrait templets of different sizes, all marked and carefully stored in a manila envelope. This is the same studio that my Leitz Valoy II came out of and it was in business a long time.

I wonder what I could use to 'freshen' the upper segments' white enamel? I am tempted to try Golden Heavy Body Acrylic, an artists paint with many uses, but I'll have to see what the maker has to say about that sort of application.

Cheers

 

[Chan Tran]

My Beseler Dichro DG head is painted white inside the mixing chamber. It has flaked off so the previous owner lined it up with aluminium foil. I removed the aluminium foil, sanded it and repaint with high temperature white paint. With foil it's almost a stop brighter but without foil the illumination is more even which is more important to me.

 

[eli griggs]

Tran, after an overlong nap, I took the decision to keep the chamber on my machine all white, for the same reason you did. I'll leave the upper as is and I've already given the lower its first coat of Titanium White, which is brighter. I did not sand but used a wooden 'probe' to scourer all the loosened paint free of the wall and simply laid the TW over what remained. This paint is very heavily pigmented and as heat is used to set acrylic paint, should be fine in this application.

An interesting note about this enlarger is the previous user had taped a light yellow gel over the diffuser panel. It was not very obvious to me when I first examined the thing, perhaps because I was so focused on the peeling paint, but that changed quickly enough when I removed the pane for painting.

I wonder if I should return this filter with the diffuser and if I do, what will it affect, especially when using VC filters? Any thoughts?

One last thing; this enlarger has a large 'dish' turret of VC filters, about 9 of them. Has anyone here used one of these before and if so, where the heck do I mount it?

Cheers

 

[MarkS]

Here's a little background info- forgive me if it's redundant. Graded photo papers are most sensitive to blue light; thus Aristo-type cold lights have a bluish output. VC papers are balanced for tungsten light, found in most enlarger light sources, either b/w or dichroic color heads. The circline fluorescent in the Omegalite doesn't match either source. What this means in practice is that VC filters will not respond "by the book" with a cold-light or fluorescent source. For example, people suggested that I put a CP40Y filter over my Aristo/Zone VI coldlight to improve the response of the VC papers. I haven't really found that necessary- I just use a #1 filter as 'normal", and Aristo now offers a tube replacement better suited for VC papers. What might happen contrast-wise with a household-type circline lamp, like yours, is a bit of a crapshoot. It might depend on the type of lamp- "cool-white", "warm-white", etc. all might have unique characteristics. IIRC, the Omegalite head was meant to provide lower contrast (than the more common condenser head), specifically for portrait applications. So it's probable that your enlarger's previous owner modified the head to get the results they wanted from their negatives. Since we don't know their methods, "why" they did something is a moot point. You're just going to have to make some tests- enjoy.

 

[eli griggs]

Thanks Mark. I've almost always been a condenser printer, with the exception of the 23c II color-head years ago, and getting serious and setting up a new darkroom with as many different enlargers/light sources as I have today is exposing me to new issues, materials and stuff I knew 20-30 years ago but never used. That being the case, any info, ever if it were redundant, which it isn't, is much appreciated.

I'll do test prints with the gel in place and removed and take a decision after awhile when I've used it with new combinations of negatives and papers with the various processing I'm exploring.

Cheers

 

[MarkS]

You might look at the website of KHB Photographics, a darkroom specialist in Canada- they have more info on older enlargers than anyone else. They're a useful complement to Harry Taylor's Classic Enlargers site.