Condensers on Omega D-series enlargers

[mgb74]

I know the condenser on a D2 should be matched to the lens focal length (I'm not talking about the variable consdenser models). But what's the impact if not matched? Does it vignette or illuminate unevenly?

Specifically, what happens with a condenser designed for 90-105mm lenses when used with a 150mm lens?

And what happens with a condenser designed for 150-165mm lenses when used with a 90mm lens?

I'm thinking in terms of print sizes up to 11x14.

Thanks.

 

[Will S]

When I fail to move the adjustable condenser in my D2V I seem to remember the circle of illumination being too small.

 

[Dan Henderson]

as an example of what happens, I recently installed an 80mm lens in my DII for medium format, but left the 6" condensors (normally used for 5x4) in. The resulting circle of illumination was much too dark at the corners. So I changed to the smaller condensors and life again was good.

 

[Bruce Appel]

What size condensors do I need for a d2 to 6X6 and 6X9? How dp you measure them?

 

[mgb74]

The information I have is:

6 1/2" *condensers are used with 135mm and 150mm lenses for 4x5 negatives

4 11/16"condensers (this is the actual diameter of the glass, part of which is under the edge of the aluminum housing) are used for lenses 75mm-90mm for 645-6x6-6x7-6x9 negatives

3 1/2" condensers (this glass is also partially covered by the aluminum housing) are used with 50mm lens for 35mm negatives

The measurements are the diameter of the glass.

 

[Dan Henderson]

Bruce: You can learn just about anything you want to know about Omega enlargers at http://www.classic-enlargers.com/. There is a forum on that site where someone else has likely already asked your Omega question, and Harry has answered it. Or if not, you can ask Harry yourself. You can also buy Omega parts and manuals from him as well. I recently bought his alignment tool and instructions and found him very easy and fast to deal with.

Dan