Can't focus the Omega 5x7 enlarger

[Ken Rice]

I acquired an old Simmon Omega NE enlarger. I think this is a predecessor to the Omega E. With the baseboard sitting on the floor it's about 58 inches tall. the light source was a rusty box with short flourescent lamps, which I discarded (I'm beginning to regret that). Instead, I mounted a Beseler Dichro 45 light source, using a 10" x 10" mirrored adapter. A friend is very interested in printing from 6cm x 17cm negatives, so we confidently went forward, trying two lenses; a 150mm and a 210mm mounted on a flat lensboard. We figured that somewhere between the lowest position on the chassis and the highest, changing the bellows length, we ought to come into focus with one of the lenses. Didn't work. Any thoughts?

[wfwhitaker]

I've never used a 5x7 Omega enlarger, but I have used the 4x5 size. And for those enlargers you need a lens cone for longer focal length lenses (135mm and longer for the D). I suspect if you had the correct lens cone for the lens you're using, you'd be able to focus OK. On a flat lens board your lens is probably sitting inside focus.

[Gem Singer]

Hi Ken,

Contact Harry Taylor at www.classic-enlargers.com. He has new 4.5 inch lens cone available. It is also available on the used market, if you can find one.

The 4.5 inch Omega extension cone will solve your problem.

[Dave Schneider]

A quick measurement of the lens to film distance should tell you if the lens cone is the problem. At 1:1 print size the lens to film distance should be twice the focal length of the lens. Are you anywhere near that?