Was there ever a 10-1/2" f6.8 Dagor?

[John Kasaian]

I've found references to a 10-3/4" Dagor but not a 10-1/2"

[Jim Noel]

I have never heard of a 10 1/2. I have been using a 10 3/4 for many years.

[Tracy Storer]

+1 on 10.75", as well as 9.5", but in the long production there may have been one at some point. Why do you ask?

[Len Middleton]

Sort of +1 on the 10-3/4", as mine is a Kenro and with markings only to f10, but opens wider...

[David Lindquist]

My Goerz literature dating from the mid-60's on doesn't show a 10 1/2 inch Dagor. A quick look at the 1940 and 1951 catalogues on the cameraeccentric website also didn't turn up a 10 1/2 inch Dagor. I wouldn't die of surprise though to find that back in the day Goerz made up some 10 1/2 inch Dagors as a special order.
David

[John Kasaian]

Well, I think I may have one. The bezel is badly scratched and was sold to me years ago as a 9-1/2" I got out the magnifier and it is definitely a 10-1/2" which really threw me off as I've never heard of one. This lens is marked Gennart which was a large camera store during the turn of the (last) century with shops in three or four large cities. IIRC, so I don't know for certain if it a Goerz or from one of the other makers. Most of the writing on the bezel has been obliterated except for Gennart, 10-1/2" and f6.8 It is in a Compound shutter. The serial # is worn off.

[Jody_S]

There's currently a 10-1/2" Gennert ("Sylvar") dagor for sale on fleabay (not mine), as well. That's what I thought of when I saw this thread. I have the 9-1/2" Gennert, it is clearly a dagor, but I don't know who made it.

[John Kasaian]

There's currently a 10-1/2" Gennert ("Sylvar") dagor for sale on fleabay (not mine), as well. That's what I thought of when I saw this thread. I have the 9-1/2" Gennert, it is clearly a dagor, but I don't know who made it.

Thank you Jody! It must be a Sylvar. I found a 10-1/2"er in the G. Gennert catalog #58, circa 1909 at
http://piercevaubel.com/cam/catalogs/1909gennertno59lp934.htm
Advertised as a budget lens for $60 circa 1908 dollars compared the $91 for a Goerz Dagor 10-3/4" of the same vintage.
WOW! That was sure must have been a lot of loot back then. Apparently the Sylvar Series 111 f6.8 (5-17.5in ) was a symmetrical anastigmat, built by R.D. Gray of New York---so a Dagor copy?

[Mark Sampson]

That would be a 6mm difference in focal length; 266.5mm vs. 272.7mm. How much tolerance is there between actual f.l. and the marking anyway? It's not impossible that the same lens could be marked either way. I think of Leica RF 50mm lenses that are actually 52mm in focal length... although I can't find a source for that notion.