Omega D-3 vignetting problem

[blackmelas]

Recently I noticed significant corner vignetting while printing 4x5 full-frame with a 135mm lens. The D-3 has a variable condenser housing with three slots for the upper condenser lens: the upper slot for 50-80mm, middle for 90-105mm, lower for 135mm, and removing the condenser lens for 150-165mm. When the vignetting was noticed naturally the lens was in its proper place in the lower slot. However when I removed the condenser lens altogether the vignetting disappeared. Will I be compromising sharpness significantly by printing without the condenser lens and a 135? Should I spring for a 150mm lens for better coverage of the negative?
Thanks for your advice,
James

 

[argus]

I don't know in how much the D3 resembles the DII, but I noticed the same when I started using the DII.
The problem was solved when I completely lowered the condensor house onto the negative carrier, using a 150mm lens.

G

 

[sergio caetano]

Ask Harry, who knows everything about it.
www.classic-enlargers.com

 

[ron mcelroy]

I used a D-3 for several years with a 150mm lens and didn't have a problems. I never used a 135mm on this enlarger so I can't comment directly to your problem. As Sergio stated above, contact Harry at classic enlargers. He made my 150mm focus track and told me how much to extend a 135mm cone where I could use a 150mm lens.

 

[Huub S]

I had the same problem with my D2 and a 135 mm. The same problem also appears when using a 80 mm and the condensor in the upper slot. So, now i print without a condensor when using a 135 mm, and with the condensor in the middle slot when using a 80 mm. Never noticed a loss of sharpness with this construction, but i didn't do any comparative testing. Someone may correct me, but my understanding is that the condensors are meant to provide an even illumination of the negative and have no direct influence on the sharpness of the print.

Huub

 

[Ronald Moravec]

I have an original D2, not the variable, with all three condenser sets.

The 6+in condensers work fine with both 135 and 150 lenses on the proper cones. The condensers are as close together as possible flat sides out, convex sides nearly touching.

I think you are using the wrong bulb. The PH111 &112 have a long neck compared to other bulbs. A shorter neck like a household bulb has will have the light source improperly positioned, ie too high up, thus causing the vignetting.

Most 135 lenses will cover 4x5 minimally. My Schneider Comparon 4.5 works perfectly from 8x10 to 20x24. The 150 Comparon was moved to the D6 Chromega for color work, but was fine for the D2.

 

[Ronald Moravec]

steve swinehart , jul 06, 2005; 11:55 a.m.
D2-V (variable condenser) head. I bought my D2-V enlarger in 1973. The variable portion of the condenser head is a movable 3rd condenser lens above the two main condensers. The correct positions of the condenser for the film formats are printed on the inside of the door to the variable condenser compartment.


The above makes more sense to me than removal of the top large condenser. you are likely to be missing the third condenser.

 

[blackmelas]

I think you are using the wrong bulb. The PH111 &112 have a long neck compared to other bulbs. A shorter neck like a household bulb has will have the light source improperly positioned, ie too high up, thus causing the vignetting.

This is a possibility. I ordered PH111 or 112 bulds from a US source forgetting about the 220v here-- knocked out a circuitbreaker altogether. So I just bought whatever bulb my shop in Athens had. Perhaps I need to try harder to find those bulbs.

Do European or Apuggers have an online source for enlarger bulbs? Or Greek Appuggers a source in Athens?

Thanks for the help,
James

 

[Jim Noel]

IN our college labe we always have students remove the condenser from the Omega enlargers when printing 4x5 negatives. SInce the diameter of the condenser is barely as long as the diagonal of the film, this is the only way we have found to eliminate the vignetting.

 

[blackmelas]

Thanks to everyone for your help. I also got a reply from Harry Taylor who said that as long as the light is even then removing the lens shouldn't cause any problems. It seems even and definitely more so than with the lens in its tray but I'll have a printing session with it to check.
Best regards,
James