Omega D2V Uneven Illumination Problem

[Marco S.]

Good Evening All,

I'm having some problems getting even illumination from my Omega D2V enlarger. I noticed that the center of my 8x8" prints are dark in the middle with lighter edges. At first I thought it was my camera, then I switched to the 23C and problem is gone.

I'm using a 80mm Nikkor lens enlarging 6x6. I have the adjustable condenser lens set to the LOWEST position. Also the lens board is flat, no cone. The condensers are clean. I exposed a sheet without a negative and you can clearly see the dense areas, not even in the center of the print as well as a hot spot in the print. Any idears on whats up with this crazy enlarger?

Thanks,

Marco S.

 

[Jim Edmond]

Are the fixed condensers installed properly (flat surfaces facing outwards)?

 

[Marco S.]

Yes, they sure are. If I move the top condenser up all the way will this soften the light enough so that the bulb is more or less out of focus?

 

[dancqu]

If I move the top condenser up all the way
will this soften the light enough so that the
bulb is more or less out of focus?

Try this. With no or the 4x5 negative carrier in place
crank up the enlarger, then note the focal distance of
the bulb on a sheet of paper. The greater that distance
the greater the covering power of the condensers. Over
coverage is OK but under equals dense centers.

The flat surfaces are to face the bulb and negative.
You are working with two condensers? The two in
some combination may make it to 35mm. Dan

 

[Marco S.]

Dan,

The condensers are facing each other, both curved edges towards each and flat sides facing bulb and negative carriers. There is a third condenser that you move to adjust for the lens size, ie 50, 80, and so on.

I did some more investigating and there seems to be a bright spot near the top of the frosted part of the bulb, facing the negative stage when it's lit. Although very small, 1-2 mm in diameter when looking at the bulb, it's very noticable. I'm thinking that the condensers are magnifying this imperfection in the frosting and therefore showing up as a bright or hot spot on the prints.

Do you think I could put a thin piece of diffusing material, like a Rosco gel and that would help soften and blend the light evenly? (Or just buy a new bulb, seeing as this one is probably 20 years old or older).

 

[dancqu]

Dan, There is a third condenser that you move to
adjust for the lens size, ie 50, 80, and so on.

I did some more investigating and there seems to
be a bright spot near the top of the frosted part of
the bulb, facing the negative stage when it's lit.

Do you think I could put a thin piece of diffusing material,
like a Rosco gel and that would help soften and blend the
light evenly? (Or just buy a new bulb, seeing as this one
is probably 20 years old or older).

Any diffuser would need to be used close to that bulb. That
bulb may be all of your problem. A diffuser can't be any more
than a partial correction. I've an Omega B8, a junior D2, for
which a new bulb arrived from Freestyle.

What does the V designate? I know of DII and D2. Dan

 

[removed account4]

Any diffuser would need to be used close to that bulb. That
bulb may be all of your problem. A diffuser can't be any more
than a partial correction. I've an Omega B8, a junior D2, for
which a new bulb arrived from Freestyle.

What does the V designate? I know of DII and D2. Dan

hi dan

the v is for auto focus i think.
i have a government-contract d3v and
there are rails that the cone/focusing bellows
rides on. the rail has shape to it ( different depending on
the fl lens used (like the cones) ) , so the bellows opens/closes
depending on the distance from the easle and the original focus.

i have heard people mention putting diffusion material
( milk glass /diffusion glass from a local glass company )
and putting it either above or below the aux. condensor that goes
above the big condensors.

good luck!

john

ps. harry taylor ( the omega-man at http://www.classic-enlargers.com ) can probably help you fix your problem. he knows these enlargers backwards and forwards.

 

[Mike Té]

Hi, John.

I hate to be the fussy nit-picker offering a correction of trivia (but....)(someone has to do it).

The "V" designation is for those Omegas with a variable condenser, the small uppermost one that is raised or lowered according to the negative size/format.

I second your vote of confidence for Harry Taylor; he's the guru and he's a genuinely nice guy.

Cheers

 

[Marco S.]

Thanks friends. I will change out the bulb and let you know if that was the problem. Yes, V in D2V is for the variable condenser in the lamphouse.

Regards,
Marco