Rebuilt Omega B66 w Light Issue

Marcia Pimentel · Dec 15, 2021

Hello,
Purchased a B66 ProLab and have rebuilt it with original parts in excellent condition with the help of KHB Photogafix. While testing it with a "new" Rogonar- S lens three small lights come through on the paper that didn't filter through before. It had the original lens before and there were no lights coming through to the paper. Could someone please le tme know, if they know, what could be causing this? Is it the lens, the lens board, or maybe something else? I'm new btw, if no one has guessed already Last time I used an enlarger was in high school 40 years ago. Thanks for any help.

Kino · Dec 15, 2021

It's probably the lens. Have you reached out to KHB? They should be able to help.

These lenses have an opening on the mounting ring that allows light to illuminate the aperture scale. Sometimes this optical relay system becomes misaligned and injects light into the printing path.

Try covering this little opening temporarily with a bit of black tape and see if the stray reflections go away. If they do, I would either return the lens to the seller and use the old lens, or leave the tape on and use it without the illuminated aperture feature.

Marcia Pimentel · Dec 15, 2021

Kino said:
It's probably the lens. Have you reached out to KHB? They should be able to help.

These lenses have an opening on the mounting ring that allows light to illuminate the aperture scale. Sometimes this optical relay system becomes misaligned and injects light into the printing path.

Try covering this little opening temporarily with a bit of black tape and see if the stray reflections go away. If they do, I would either return the lens to the seller and use the old lens, or leave the tape on and use it without the illuminated aperture feature.

Thank you. I think it may be the lens too but it is clear and really clean. Looks new. I didn't buy it from KHB btw... it was a private seller. I will try the tape. I'm pretty sure this is the cause. Appreciate it.

Nicholas Lindan · Dec 15, 2021

If you cover the lens with a lens cap (or something like it) do the lights disappear? That at least narrows things down.

If it isn't the lens: Find where the light is coming from by tracing the path of the light with your finger. Place your finger so the light shines on it, raise your finger (keeping the light on your finger) and you should hit the offending part of the enlarger.

If it is the lens then it becomes a bit more complicated: Try placing a mirror on the easel so it is under the light. Then look in the mirror an see if you can see the source of the light by looking through the lens. You may have to raise the mirror to get a better view. You don't really need a mirror but it beats trying to look up through the lens and putting a crick in your neck. Also try removing the lens and looking up through the hole and see if there is something leaking light in the same pattern you are seeing on the easel.

Marcia Pimentel · Dec 15, 2021

Nicholas Lindan said:
If you cover the lens with a lens cap (or something like it) do the lights disappear? That at least narrows things down.

If it isn't the lens: Find where the light is coming from by tracing the path of the light with your finger. Place your finger so the light shines on it, raise your finger (keeping the light on your finger) and you should hit the offending part of the enlarger.

If it is the lens then it becomes a bit more complicated: Try placing a mirror on the easel so it is under the light. Then look in the mirror an see if you can see the source of the light by looking through the lens. You may have to raise the mirror to get a better view. You don't really need a mirror but it beats trying to look up through the lens and putting a crick in your neck. Also try removing the lens and looking up through the hole and see if there is something leaking light in the same pattern you are seeing on the easel.

Hi,
Thank you for your help. Those are great ideas It is the lens. When it is covered there is no extra light. Going to try the mirror now and will check back in.

Nicholas Lindan · Dec 15, 2021

Did you cover just the lens?

The reason I ask is that one source of the lights may be old holes made in the lensboard for a no-longer used mounting flange. Or missing screws in the present mounting flange. If a bit of card was used to cover the lens it may have covered the light from these holes.

jvo · Dec 15, 2021

a belated welcome to photrio...

MattKing · Dec 15, 2021

Welcome.
Can you show us pix of the lens mounted on the board, both front and back?

Marcia Pimentel · Dec 15, 2021

Yes I used the lens cap and there was no light leakage. The lensboard looks to be in great shape.

jvo said:
a belated welcome to photrio...

Thank you

Marcia Pimentel · Dec 15, 2021

MattKing said:
Welcome.
Can you show us pix of the lens mounted on the board, both front and back?

Yes, I can do that. It will be a few hours to do that.

Rick A · Dec 15, 2021

I have a couple of lens boards that will fit your enlarger, free of charge.

Marcia Pimentel · Dec 15, 2021

Rick A said:
I have a couple of lens boards that will fit your enlarger, free of charge.

Hey! Thanks

Marcia Pimentel · Dec 16, 2021

WELL, here is the deal.... there is no light leaking through this morning I can only test it in total darkness and since it is not in a darkroom but in a workroom, I had to wait . Used the same roll of negatives and the enlarger hadn't been moved. I did tinker with the lensboard to remove it but I didn't find anything and just wanted to try it again before I disassembled anything.

Rebuilt Omega B66 w Light Issue

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