Omega D5 lens retaining ring question

MNaPh

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I have an Omega D5XL that was recently given to me. I've been bringing it back to life and it's pretty much there. However, I have the 3 lens turret and I want to mount my M39 lenses to the Omega extended lens boards. The OEM ring from Omega was 44.5mm OD whereas the more standard Beseler ring was 47.5mm OD.

I have seen mention that the larger ring will not fit into the extended board and the Omega rings are seemingly impossible to find after a few days of intensive searching. So, has anyone here had experience with using the more standard 47.5mm ring on the Omega lens boards and how well/easily were you able to seat the lens?

With this one extremely wacky exception Omega parts are readily available, this isn't the piece that I was expecting to completely grind my entire production to a halt.
 

MattKing

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MNaPh

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I saw the KHB mention and they are definitely out of stock. That's why I was hoping that someone here had some firsthand experience. I also reached out to SKGrimes because I've purchased a few custom flanges for older lenses, in the past. The quote of $75+shipping per ring was more than just a little outrageous considering the minimal amount of work and material involved with machining the rings. They do great work but that price is ridiculous.
 

Pieter12

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Maybe you should walk away from the turret and just mount the lenses on separate boards. I've heard the turret can introduce alignment issues anyway.
 
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MNaPh

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Yeah, I was thinking about going without the turret but I LOVE convenience factor. That will probably end up being the way I go but, at the moment, I'm extremely annoyed by Omega's short sighted engineering on such a simple part.
 

MattKing

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Could you repurpose a 39mm filter with the glass removed?
I linked to the KHB reference because in some cases there are threaded lens plates that make a retaining ring unnecessary.
FWIW I used a lot of different rings with a lot of different lenses and lens plates when I had my D6 and the two turrets I had, I only ran into a problem once or twice with a couple of the extended cone lens plates, and when I did I just grabbed another thinner retaining ring from my stash. I didn't even realize until now that there were standards.
 

wiltw

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Beseler rings for use on their 3-lens turret would cost $60 new in the 1990's...and 100% inflation has occurred between 1990 and 2020.
 

MattKing

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ic-racer said:
The ring is too thick? Just grind it down.
Click to expand...
It is the outer diameter of the ring that the OP has problems with, not its thickness (I think).
Although it occurs to me that you might be meaning that when you say "too thick".
 

ic-racer

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MattKing said:
It is the outer diameter of the ring that the OP has problems with, not its thickness (I think).
Although it occurs to me that you might be meaning that when you say "too thick".
Click to expand...
Yes, grind the outer diameter.
 
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MNaPh

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wiltw said:
Beseler rings for use on their 3-lens turret would cost $60 new in the 1990's...and 100% inflation has occurred between 1990 and 2020.
Click to expand...

The Beseler rings are actually $13 CAD now and the Omega are $40 CAD so the inflation has turned into deflation overall on these.

ic-racer said:
The ring is too thick? Just grind it down.
Click to expand...

I'd be happy to go the grinder route but I live in a small apartment downtown and those tools, other than sandpaper of course, aren't really available to me so that option sadly eliminated itself.


The thread pitch on filter rings is .5mm and for lenses it's 1mm so they aren't interchangeable BUT based on your experience Matt maybe I'll get lucky and everything will fit otherwise I guess the turret and lens boards will find their way to another owner and I'll have to settle for individual mounts. It's definitely not a catastrophe I just hate being defeated by small design flaws.
 

MattKing

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The single lens mount generally needs exactly the same lens plates as the turrets (with a few exceptions) so giving up on the turret isn't going to help you much.
 
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MNaPh

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Pieter12 said:
Could you use the threaded lens plate on the turret?
421-056 Flat Oval Lens Plate with 39mm Leica threaded flange
Click to expand...

That was actually my original thought when I ran into the problem but then I remembered that the reason I had to opt for the extended boards was because of clearance issues between the turret and the lenses. I'm guessing there have to be some very low rise rear lens elements out there but my EL-Nikkors are just too long for the flat boards. However, you just got me thinking that maybe I could find some inexpensive threaded flat boards and just bond them to the extended boards to cobble something usable together.
 

MattKing

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FWIW, I think the 39mm retainer rings I used for my Beseler 67C enlarger - some of which were Beseler - are the skinny ones.
 
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MNaPh

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MattKing said:
The single lens mount generally needs exactly the same lens plates as the turrets (with a few exceptions) so giving up on the turret isn't going to help you much.
Click to expand...

Well, the single mounts won't require the extended boards. I only need the extended versions to provide clearance between the lens and the turret. The cones on the extended boards taper slightly and that seems to be where the rub comes in.
 

gordrob

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I may have what you are looking for but I will first need to find my calipers to check the outside diameter. How many did you want. I am sure these came off an Omega turret system.
Regards
Gord
 
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MNaPh

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gordrob said:
I may have what you are looking for but I will first need to find my calipers to check the outside diameter. How many did you want. I am sure these came off an Omega turret system.
Regards
Gord
Click to expand...

I'm looking for 3 of them Gord.
 

MattKing

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MNaPh said:
However, you just got me thinking that maybe I could find some inexpensive threaded flat boards and just bond them to the extended boards to cobble something usable together.
Click to expand...
You could bond the thicker retaining ring to the outside of the extended lens plate.
 

MattKing

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MNaPh said:
Well, the single mounts won't require the extended boards. I only need the extended versions to provide clearance between the lens and the turret. The cones on the extended boards taper slightly and that seems to be where the rub comes in.
Click to expand...
Actually, they do. Without the cones you wont be able to push the board into place because the rear of the lens will block that.
On the D5 and D6 you don't mount the board or turret from below, you slide it in from the front.
 
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MNaPh

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MattKing said:
Actually, they do. Without the cones you wont be able to push the board into place because the rear of the lens will block that.
On the D5 and D6 you don't mount the board or turret from below, you slide it in from the front.
Click to expand...

Yeah, I see what you're saying now.
 
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