Omega D-2V focus shift

[norm123]

Hi all

I printed today and I realized a out of focus problem 1-2 minute after I did it.

What's wrong? Something loose...The head is tight on the column. Is it possible that there is a problem with the sturdiness of the bellow, I mean distance lens-film?

I should see that tomorrow morning...but if you have experience with that, please, your tips would be appreciated.

Regards

 

[ic-racer]

Is this a new problem for this enlarger? Do you have the glass negative carrier? You might want to look for one, if not.

 

[Born2Late]

Most likely your negative is "popping". This is caused by expansion due to the heat from the lamp, which causes it to expand and bow. I usually turn the lamp on for a short period before focusing then focus after the negative pops. You can then expose the paper relatively quickly after focusing (before the negative cools much), or preheat the negative again right before exposing the paper.


The other option is a glass carrier as suggested above.

 

[norm123]

Most likely your negative is "popping". This is caused by expansion due to the heat from the lamp, which causes it to expand and bow. I usually turn the lamp on for a short period before focusing then focus after the negative pops. You can then expose the paper relatively quickly after focusing (before the negative cools much), or preheat the negative again right before exposing the paper.


The other option is a glass carrier as suggested above.

I'm thinking you're right about popping negative. It's a problem with heat. So, I'll print this morning. Glass carrier is a good idea.

Thanks all for responding.

 

[Rick Jones]

I would first try to pin down what is causing the problem - focusing rack slipping or more likely negative popping. If you have a grain focuser after focusing continue to watch the image. After 10-20 sec. if heat is effecting the negative the grain will blur. Let the head cool down and check again. If the grain is back in focus you know the negative is popping. I know of 3 options: glass negative carrier, heat absorbing glass or LED head. I have tried all 3 with my D2V and finally settled on the LED head.

 

[Jim Jones]

I had negative popping problems with an Omega D-22 during high volume printing sessions. The solution was to slightly reduce enlarger lamp voltage to extend lamp life and leave the lamp on during the entire printing session. After the image was focused and composed on the easel, the blocked out red filter beneath the lens was swung into place, paper was inserted in the easel, one hand was held beneath the lens, the filter was swung away, and after a second or two, exposure was controlled by the first hand. Another solution I considered but never tried was to cool the enlarger head by forcing air through it. A small blower connected to the enlarger head through a flexible hose to reduce vibration should accomplish this.

 

[Marco Buonocore]

The tension on the Omega D2 focus knob can get loose, causing focus to slip. You see there's a screw that can be tightened - it's pretty obvious if you look for it. It might need an Allen key? I forget. Next time I'm in the darkroom I can snap a picture of it to show you if that helps.

Of course a glass carrier is a good idea as well.

 

[Ronald Moravec]

Is there not a heat absorbing glass that might be missing. Looks like 4x5 glass sheet.

For max quality, glass carrier is always better. You will need anti newton glass on the top.

Omega only sells 4x5 glass carrier and they claim it to be universal. Locating pins prevent a strip of film going down the middle so a machinist needs to relocate them.

Or file out a 35mm and put AN slide mount glass in the top. This is touchy, but mine works fine.