Filter size for Turner-Reich Anastigmat Ser. II

[ntenny]

I've acquired a convertible Gundlach T-R Anastigmat Series II---focal lengths 12"/21"/28", f/6.8, labelled for 8x10. This seems to be the No. 5 lens in the series, per a Gundlach catalog at http://www.cameraeccentric.com/html/info/korona_2.html.

There are filter threads, the diameter seems right for a 55mm filter, but either the diameter is just *slightly* wrong or the thread pitch is different. I can't find anything on the lens that would indicate the diameter. It's certainly bigger than 52mm, and I don't think I've ever heard of a 53mm or 54mm size---or were there once filters in inch sizes, and this should take a 2 1/4" filter (which is what the catalog gives as the diameter of the elements)? It's too early for series filters, right? Or are the threads not for filters at all but for something else?

Thanks

-NT

 

[E. von Hoegh]

Series filter with a slip on adapter. The threads you see are not standard filter threads, but you could have someone like S.K. grimes machine an adapter.

 

[shutterfinger]

The threads in the front of lens made up through the 1950's maybe the 1960's are for the front element retaining ring only.
Filters were made in series sizes IV through IX. Adapter rings for each series size were made in fractional steps for the various different sized lens barrels of the front lens group.
Series IV- 8mm and 16mm movie cameras
Series V- 3/4-1 3/16 inch
Series VI-1 1/4-1 21/32 inch
Series VII- 1 11/16-2 inch
Series VIII- 2 1/16-2 5/8 inch

Measure the outside diameter of the lens front lens barrel and look for a Series filter adapter that the measurement of the lens matches and series filters or as E says have a machinist custom make a threaded adapter. Some series adapters were marked in millimeters so convert the fraction to decimal and multiply by 25.4

 

[Jon Shiu]

Or, you could just glue in at step-up filter adapter ring.

Jon

 

[E. von Hoegh]

The threads in the front of lens made up through the 1950's maybe the 1960's are for the front element retaining ring only. Filters were made in series sizes IV through IX. Adapter rings for each series size were made in fractional steps for the various different sized lens barrels of the front lens group.
Series IV- 8mm and 16mm movie cameras
Series V- 3/4-1 3/16 inch
Series VI-1 1/4-1 21/32 inch
Series VII- 1 11/16-2 inch
Series VIII- 2 1/16-2 5/8 inch

Measure the outside diameter of the lens front lens barrel and look for a Series filter adapter that the measurement of the lens matches and series filters or as E says have a machinist custom make a threaded adapter. Some series adapters were marked in millimeters so convert the fraction to decimal and multiply by 25.4

Actually, most of these lenses - and the Turner-Reich specifically, but old Dagors, etc have no retaining ring in front. The threads might have been used during manufacture, for instance to hold the brass cell onto an arbor.

 

[John Koehrer]

It's also one lens that E. Weston used at one time.

Doesn't really help, just a bit of trivia.

 

[ntenny]

Thanks, everyone. It looks like the threads are the same as the threading between the barrel and the lens cells, so maybe they're some kind of strange artifact of the manufacturing process. I've got some ideas about fabricating a slip-on adapter---paying for custom machining seems like an unnecessary expense unless I end up with a collection of lenses with the same threads.

-NT