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DJGainer
21-Apr-2008, 10:42
I just picked up my first lens, but it is mounted in a DB shutter. I want it in a Copal 0, but all the Copals I am looking at have no markings on the aperture scale. Is this a process I can take on myself, or should I find a professional to do this calibration? And if so, who do you recommend?

Dave

Peter K
21-Apr-2008, 10:55
Every lens needs a special aperture scale. This question is asked very often. With the "search" fuction this threads can be found easily. E. g.
http://www.largeformatphotography.info/forum/showthread.php?t=32332&highlight=aperture+scale

mrossano
21-Apr-2008, 11:23
As another possibility, Prontor Professional and later model Compur shutters use the same scale for all lenses of a particular maximum aperture (actually, the Prontors have two variations of some or all of the max apertures, to allow appropriate minimum apertures) with the calibration achieved with an adjustable linkage between the pointer and the actuator. If you can find one of these with the appropriate scale, at a suitable price, you may be better-off.

DJGainer
21-Apr-2008, 11:39
Couldn't I just mount another lens, meter the light coming through it at the different apertures, then mount the new lens and record the apertures on the scale when the meter readings correspond to those on the first lens?

Scott Kathe
21-Apr-2008, 12:20
If you are just getting started I'd have a professional mount it for you and do the aperture scale. That may end up cutting down on potential problems and troubleshooting in the future at the expense of cost. I would get in touch with SK Grimes (http://www.skgrimes.com/) and see what it will cost you-it will probably be expensive. You might be better off contacting Jim at Midwest Photo (http://www.mpex.com/index.htm) and see if you can trade in the lens you have for another in the type of shutter you want.

Scott

David Karp
21-Apr-2008, 12:27
If it is a currently manufactured lens, there may be another option. Talk to a photo equipment repair shop and ask them to order the Copal shutter for that lens from the lens manufacturer.

I did that with my 90mm and 75mm Grandagon-N lenses that originally came in DB mounts. The shop ordered the lenses with the aperture scales and we screwed the elements right in! Both lenses were good to go.

Bob Salomon
21-Apr-2008, 12:36
As another possibility, Prontor Professional and later model Compur shutters use the same scale for all lenses of a particular maximum aperture (actually, the Prontors have two variations of some or all of the max apertures, to allow appropriate minimum apertures) with the calibration achieved with an adjustable linkage between the pointer and the actuator. If you can find one of these with the appropriate scale, at a suitable price, you may be better-off.

You are confusing things.

Prontor Werke offered three different aperture sticks for the Prontor Professional. One each for the 0, the 01 and the 3 shutters (there were only two different sizes of the Professional. For the 0 lenses there was an adapter thread in the shutter. Each of these three sticks then had several different aperture tapes available for each size depending on the maximum and minimum apertures of the lens mounted in the shutter. Thus a 90mm 6.8, 90mm 8.0 and 90mm 5.6 each had the same stick but different aperture scale stickers for the 0 shutter size. We fairly recently threw out boxes of these scale stickers as we no longer had anything to mount them on.

DJGainer
21-Apr-2008, 15:13
If it is a currently manufactured lens, there may be another option. Talk to a photo equipment repair shop and ask them to order the Copal shutter for that lens from the lens manufacturer.

I did that with my 90mm and 75mm Grandagon-N lenses that originally came in DB mounts. The shop ordered the lenses with the aperture scales and we screwed the elements right in! Both lenses were good to go.

Well, if I can find a Copal 0 for a Schneider Super Angulon f/8 90, I'll be in great shape!

domenico Foschi
21-Apr-2008, 15:18
my SA has a 0.0 shutter

Scott Kathe
21-Apr-2008, 16:55
my SA has a 0.0 shutter

Mine is in the 0 shutter-good luck:)

DJGainer
21-Apr-2008, 17:10
It is a recent manufacture (14xx...) so I am sure there is a shutter available. I contacted SK Grimes, so hopefully I can get this worked out for the price of a new shutter!

DJGainer
22-Apr-2008, 09:13
It is a recent manufacture (14xx...) so I am sure there is a shutter available. I contacted SK Grimes, so hopefully I can get this worked out for the price of a new shutter!

Just checked the Schneider website; it looks like the lens is older than I thought, having been manufactured in the 80s.

David Vickery
22-Apr-2008, 09:29
If you want to take care of this yourself, then all you have to do is divide the focal length of the lens by the measured diameter of the aperture. That will equal the f-stop at that position on the aperture control lever. Using millimeters is best. Do this for many aperture openings on the shutter and then do film tests to verify that you have marked the shutter properly and more importantly, that you know what you will get on film at each mark that you put on the shutter--that's all that matters anyway.

DJGainer
22-Apr-2008, 09:45
If you want to take care of this yourself, then all you have to do is divide the focal length of the lens by the measured diameter of the aperture. That will equal the f-stop at that position on the aperture control lever. Using millimeters is best. Do this for many aperture openings on the shutter and then do film tests to verify that you have marked the shutter properly and more importantly, that you know what you will get on film at each mark that you put on the shutter--that's all that matters anyway.

As if I needed more encouragement...

I suppose my next question would be, what do I use to mark the scale? I have no equipment to engrave the plate.

tim810
22-Apr-2008, 09:55
I did this exact thing with my 355 Schneider Convertible out of a DB mount. I had an extra shutter from a 240 Caltar that I used. I just measured the diameter at specific apertures on the db mount with calipers and compared the diameters to the copal shutter and made a mark on a piece of white tape to correspond to the said aperture. I than tested the marks at 3 different apertures to verify exposure. It worked and is still very reliable.



As if I needed more encouragement...

I suppose my next question would be, what do I use to mark the scale? I have no equipment to engrave the plate.

Skorzen
22-Apr-2008, 10:33
I posted a response to your ad over at APUG but just thought I would share those same thoughts here. Unless you got a killer deal on the lens (and maybe if you did) I think it is quite possible that it would be cheaper to sell (or return if that is an option) the DB mount lens and get one in a normal shutter. 90mm SA's go for small money on ebay these days. For a 00 single coated lens they can be had for $175-$250 a 0 multicoated lens can be had for $300-400. A new Copal 0 shutter will set you back $200 from B&H with no scale (probably $50 from SK Grimes).

Oh and one other note the 0.0 shutter that was mentioned before is a copal 0 from what I understand. There is a 00 but that is different form 0.0.