A Compound/Compur HYBRID Shutter On An Old Dagor??

[leighmarrin]

I've got a somewhat beat-up 8.25" f6.8 Goerz Dagor that I paid $40 for at an antique store. Its shutter only fires at about 1/100th for all marked speeds, it is missing a flange (about 45mm diameter on external threads), and the rear cell has some rainbow-ish seperation covering about 10% of the lens diameter. The lens serial number is 395187, marked on both cells. I'm going to improvise a lensboard--if it is at least as sharp as an old uncoated Tessar of the same focal length, I'll put some money into fixing its shutter and finding a flange.

But the shutter is mystifying to me--can't find any pictures like it via Google... While it is marked COMPOUND at the bottom, and has the Compound air cylinder on top, it looks more like a dial-set Compur. Its speed dial has the counter-clockwise arrow found on some old Compur shutters, and the fastest marked speed is 1/150th--faster than any Compound I've seen. And its T/B/I selection dial is in the typical Compur spot.

So might this be one of those cobbled-together B&J Dagors I've read about? Or some uncommon factory variant?

Thanks for any info or clues...

--Leigh M. in Santa Barbara, Calif.

[Steven Tribe]

Looks like a standard Compound shutter to me!
Compur, Compound and the many varieties of the Compound (like IBSO) were made by the same company. I think only the large sizes retained the "odd" rear 3 pin position for TBI.

[leighmarrin]

Well.. maybe I did not "Google" long enough... of the many Compound shutter images I found, none had the T/B/I setting at 9 o'clock, and none had the CCW-pointing arrow on the shutter dial. And all had the "M/B/Z" setting at the bottom at 6 o'clock.

Glad to hear it's a standard Compound--I was afraid it might be some "kluge" cobbled together from different shutter parts, and hence probably unfixable.

EDIT UPDATE: Ooops! Just "Googled" "Compound Shutter" again, and the fifth photo from Google Images is identical to mine... sorry about the wasted bandwith...

[Steven Tribe]

I believe this variation is called the compur/compound or rad-compound?
The speeds of the compounds were:

00 - 1/300
0 -250
1 -200
2 -150
3 -100
4 -75
5 -50

[E. von Hoegh]

Nothing uncommon there, it's just a late Compound. The earlier small ones had the IBT selector just above the aperture scale, the very early ones had a pneumatic release as well. I have a 6" Dagor in such a shutter.
It fires at one speed only because the piston is stuck. That dent in the front cell would make me check the parralelism of the seating surfaces. A Compur flange might fit.

Edit - It is a real Dagor.

[leighmarrin]

How would I check the parralelism of the seating surfaces? While the rear cell has a little seperation, the front cell looks fine, except for the front ring dent. Also will shoot some film thru it--hopefully it will be as good as a 21cm f/4.5 uncoated Tessar I have, or better.

I measured the OD of the mounting threads as about 45mm. The closest listing on SK Grimes' flange list is for a "Compur #2 Obsolete --43.95-M.9"

Thanks for all the info.

[E. von Hoegh]

How would I check the parralelism of the seating surfaces? While the rear cell has a little seperation, the front cell looks fine, except for the front ring dent. Also will shoot some film thru it--hopefully it will be as good as a 21cm f/4.5 uncoated Tessar I have, or better.

I measured the OD of the mounting threads as about 45mm. The closest listing on SK Grimes' flange list is for a "Compur #2 Obsolete --43.95-M.9"

Thanks for all the info.

Ideally, you would measure the parralelism by unscrewing the cells, placing the shutter on a surface plate, and measuring the height from the rear seat to the front seat with a dial indicator. Ypu could measure the parralelism with dial calipers, lacking a surface plate and dial indicator.
This lens will have more coverage and less flare than a Tessar.

[TheDeardorffGuy]

Years ago, after the Berlin wall came down I bought about 25lbs of Compound Shutters from a repair agency in Dresden Germany. Many were brand new in boxes and were made in East Germany as late as 1982. Most of them had the rocking lever TBI ot 6 o'clock. Several were just like the one in the first post. All had the temperature compensation screw. I love these shutters and remounted many lenses in them for customers.

[leighmarrin]

Ideally, you would measure the parralelism by unscrewing the cells, placing the shutter on a surface plate, and measuring the height from the rear seat to the front seat with a dial indicator. Ypu could measure the parralelism with dial calipers, lacking a surface plate and dial indicator.
This lens will have more coverage and less flare than a Tessar.

I think I can dig up a dial calipers: what sort of tolerances do you suppose would be acceptible? +/- .003" or?

[E. von Hoegh]

I think I can dig up a dial calipers: what sort of tolerances do you suppose would be acceptible? +/- .003" or?

.0005" would make me happy. .001" is probably more realistic.