Diminutive Dagor Identity Crisis

[jim_galli4]

Having welcomed this tiny Dagor into the ever expanding fold I'm

wondering if it is an American Optical Co. product and if there is a

way to date it by Serial No. Help from you Dagor experts is

appreciated. No mention of a 5 1/2" Dagor in any of my older

literature. Also wondering if it will squeeze around 5X7. I'll try

it later this week after the 14 hour days are through.<br><center>

<p><img src=http://tonopahpictures.0catch.com/01/Dagor55-2.jpg><br>

<b><i>5½ Inch Dagor</i></b>

[dhananjay_n]

The serial number dates it at between 1927 and 1937. C P Goerz American Optical was originally a branch of C P Goerz, Berlin. I don't know when American Optical became an independent company - somewhere around world war I, if it hadn't become an independent company earlier, it wouldhave been seized during the war. The German Goerz merged into Zeiss-Ikon in 1926 but Zeiss made very little apart form the Dagors. The American firm continued till the 70's when they were purchased by Schneider. Given the date indicated by the serial number, I'd say it was probably a product of the Zeiss-Ikon time. Cheers, DJ

[dhananjay_n]

The serial number dates it at between 1927 and 1937. C P Goerz American Optical was originally a branch of C P Goerz, Berlin. I don't know when American Optical became an independent company - somewhere around world war I, if it hadn't become an independent company earlier, it wouldhave been seized during the war. The German Goerz merged into Zeiss-Ikon in 1926 but Zeiss made very little apart form the Dagors. The American firm continued till the 70's when they were purchased by Schneider. Given the date indicated by the serial number, I'd say it was probably a product of the Zeiss-Ikon time. Cheers, DJ

[dan_fromm2]

Jim, per the Vade Mecum C. P. Goerz was merged into the Zeiss Ikon combine around 1925 and stopped selling lenses badged Goerz around 1926 at serial numbers around 660,000. Also, not that its relevant, the oldest Goerz lens in Compur shutter that the Vade Mecum's authors have seen dates to 1923.

 

So, given your baby's s/n, it is probably by Goerz American Optical Company, not to be confused with American Optical Company, also known as AO. AO was primarily a microscope manufacturer, as far as I know didn't (all pile on now) make much in the way of photographic objectives.

 

Cheers,

 

Dan

[jim_galli4]

</center>Thanks all. I noticed later that the shutter says "Licensed U. S. Pat. Mar. '31 Dec. '24 1914 which would indicate that it likely is indeed US and post 1931. Wish there was a good written history of all things Goerz.

[arne_croell]

The fact that the focal length is only listed in inches also points to a US origin. On the other hand, the German Z-B-M on the shutter dial instead of T-B-M (Z: Zeit vs. T: time) might mean that the German-made Compur was not originally made for export to the US....

[john_kasaian1]

Jim,

 

 

I looked at Eddie Bolssetzian's list on Large Format Photography:more on classic lenses. Initially it places the serial # between 1927 and 1937(#751240-756909) If production ran around 621 units/year(maybe more, since we're pre-depression in 1927) That would put your lens in the 1927-1928 vintage. Of course math in my worse subject(bet y'all thunk it wuz inklis!);-)

[allen_whittier]

5x7, good choice of format. A 5 1/2" lens has to produce a 73 degree image circle to cover 5x7 with no movement. I don't know what yours will do but Dagors tend to throw an image circle into the 80s at f22. An inch of rise with 5 1/2" only requires an 81 degree circle. You probably have 4 or 5 degrees of tilt; maybe more.

 

I use a 4 3/4 on my 5x7. It needs to throw an 81 degree image circle just to cover 5x7, and I still have movement with it. I'll bet you'll be pleased when you put your lens to light and film. Astronomers have a term for the first time they use a new telescope; "First light". It's often an excuse for a party. First Light also does a good job of describing the thrill of putting a new, or old, lens on the camera for the first time. Don't wait to long.

[chris_hopley]

In reply to Arne Croell's contribution, I have a German Compur shutter that has Z-D-M (as opposed to Z-B-M). Reading the German instructions for the shutter, the D presumably stands for Druck (=pressure), meaning that the shutter stays open as long as pressure is applied to the release lever. I find it curious that they changed the D to a B for the "export" version, but kept the Z. Maybe it's just a later version, after B came into widespread use...