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View Full Version : Can lenses in Sinar DB mount be remounted in copal shutters?



duff photographer
21-Sep-2017, 21:03
Howdo,

I ask the question as I see many second-hand DB mount lenses (principally the Rodenstocks) being advertised at a much lower price than those in copal shutters. Even taking into account locating copal shutters and their cost it still works out cheaper than buying the lens in an original copal.

May I assume that the lower price is due to one or some (or none) of the following?

1. Lack of copal shutters now that they are no longer made (this I doubt).
2. Difficulty of converting the lens to a copal shutter due to some proprietary aspect of the Sinar DB mount specifically made by Rodenstock.
3. Difficulty of any conversion requiring specialised equipment/skill pushing the cost up to the point of not being worth it.
4. Some other aspect I've overlooked.


Many thanks,
Duff

Richard Wasserman
21-Sep-2017, 21:12
I bought a 210mm App Sironar S in a DB mount and put it in a Copal shutter. I simply unscrewed the front and rear lens sections (paying attention to any shims) and screwed them into the Copal shutter, probably took about 2 minutes and it works perfectly. Easy Peasy

Peter De Smidt
21-Sep-2017, 21:14
My experience matches Richards.

plaubel
21-Sep-2017, 23:35
As far as I know, many DB-lenses fit into a Copal shutter because they have been sold in a Copal shutter, too.
I transferred a 75mm Grandagon from DB to Copal.
Ritchie

Bob Salomon
22-Sep-2017, 03:42
All you need is the proper size shutters, a pair of the proper aperture scales and, maybe some shims if the performance of the lens drops in the new mount.

duff photographer
22-Sep-2017, 16:18
Thanks Richard, Peter, Ritchie, and Bob - I very much appreciate your responses. :)

I have access to a stash of copal shutters so I think I shall take advantage of the low cost of DB mounted Rodenstocks and have some fun. Please don't tell anyone as the price may go up on these things now.


Cheers,
Duff

Jody_S
23-Sep-2017, 18:15
I have access to a stash of copal shutters so I think I shall take advantage of the low cost of DB mounted Rodenstocks and have some fun. Please don't tell anyone as the price may go up on these things now.



It's that stash of copal shutters we'd all be interested in, I think.

Steven Tribe
23-Sep-2017, 23:59
+1 to the copal comment!

There is still a very large reserve of the less iconic lenses from the Sinar era.

mortensen
10-Aug-2018, 14:09
... reviving this great thread, since I'm about to dip into a similar endeavor.
Is there anywhere, where I can buy aperture scales and are they easily 'refittet' into an existing Copal shutter? I'm looking at an f4.5 lens, and the Copal shutter begins at 5.6... but maybe that's not a problem?

Previously, I have only unscrewed lens elements to change lens board.
Thanks...

Bob Salomon
10-Aug-2018, 14:14
... reviving this great thread, since I'm about to dip into a similar endeavor.
Is there anywhere, where I can buy aperture scales and are they easily 'refittet' into an existing Copal shutter? I'm looking at an f4.5 lens, and the Copal shutter begins at 5.6... but maybe that's not a problem?

Previously, I have only unscrewed lens elements to change lens board.
Thanks...

Just contact the factory and tell them which lens and shutter that you need scales for. They have them.

mortensen
10-Aug-2018, 14:23
thanks again - so helpful!

Carsten Wolff
10-Aug-2018, 19:37
thanks again - so helpful! ... What Bob said: Don't forget to mention which focal length that scale is for, not just the max aperture.... SKGrimes and others can also make/send you matching scales.

mortensen
11-Aug-2018, 00:01
... What Bob said: Don't forget to mention which focal length that scale is for, not just the max aperture.... SKGrimes and others can also make/send you matching scales.

Thanks, Carsten. Bob mentioned contacting the Copal factory... Japanese, I see. And SK Grimes is in the States. Do any of you know of a place in the EU that has these scales?
And, finally, how come it is so important to match both focal length and max aperture? Is it in order to know precisely the selected aperture in regard to exposure?

Oslolens
11-Aug-2018, 00:28
Thanks, Carsten. Bob mentioned contacting the Copal factory... Japanese, I see. And SK Grimes is in the States. Do any of you know of a place in the EU that has these scales?
And, finally, how come it is so important to match both focal length and max aperture? Is it in order to know precisely the selected aperture in regard to exposure?Robertwhite got me scales for an Apo-Symmar 10 years ago - I thought I had discovered a secret because the lens could open ca one more stop than f5.6, but the scales was for a wide angle. Nikon shutters are harder to get new scales for, as they are "printed" on a hole ring. DB mounted lenses: I sold my mickey-mouse style lens in shutter on board, since shutter was glued open and one of the arms was removed. A really good job!

Sent fra min D6503 via Tapatalk

mortensen
11-Aug-2018, 00:56
Robertwhite got me scales for an Apo-Symmar 10 years ago - I thought I had discovered a secret because the lens could open ca one more stop than f5.6, but the scales was for a wide angle. Nikon shutters are harder to get new scales for, as they are "printed" on a hole ring. DB mounted lenses: I sold my mickey-mouse style lens in shutter on board, since shutter was glued open and one of the arms was removed. A really good job!

Sent fra min D6503 via Tapatalk

Thanks, Oslolens - very informative. I've just contacted Robert White

Bob Salomon
11-Aug-2018, 05:31
Thanks, Carsten. Bob mentioned contacting the Copal factory... Japanese, I see. And SK Grimes is in the States. Do any of you know of a place in the EU that has these scales?
And, finally, how come it is so important to match both focal length and max aperture? Is it in order to know precisely the selected aperture in regard to exposure?
Rodenstock factory, shuttermakers donít make scales, lens manufacturers do.

Bob Salomon
11-Aug-2018, 05:33
Thanks, Oslolens - very informative. I've just contacted Robert White

Why would you do that? White adds profit to what they sell, it would be cheaper, and faster, to call Rodenstock directly. That would save the retailerís charges.

Thalmees
11-Aug-2018, 06:59
...
(paying attention to any shims)
...

Precise and Correct.
Lens cell spacers(shims) are lens specific not design/model specific. Has specific thickness.
While it's function could be roughly checked(depends on focal length), say at infinity, close distances or image edges, it's functions could not be assessed except in lab. Short focal length lenses are much difficult or impossible to find the effect of shims on image quality by just simple test on GG(ground glass) or even on film.
But, we all know that, shims are not arbitrary and not there by chance.
.


...
where I can buy aperture scales
...

If I understand you correctly, you can do it your self. Save money and more importantly time.
Please review: "Recreating a Missing Aperture Scale - A How To"
http://www.largeformatphotography.info/forum/showthread.php?147102-Recreating-a-Missing-Aperture-Scale-A-How-To&p=1455981#post1455981


...
I'm looking at an f4.5 lens, and the Copal shutter begins at 5.6
...

Unless you are planning to use your lens at wider than f/5.6, you will only lose 1/2 stop of brightness on your GG.