Lens mounting flanges - measurements and other info

[Tin Can]

That will work if the glass can be removed, to protect it from Cerrosafe heat

Some lighter lenses may even be able to use a Cerrosafe flange

There is a guy on a facebook brass lenses group that is making flanges. They seem to be working for those that bought them. I talked to him about making a flange for a rare lens of mine, but without having to send the lens. My idea is to use Cerrosafe, a low melting point metal that is used for casting and measuring things accurately. I'm going to make a cerrosafe dummy flange, send it to him, and have him replicate it in brass or alum.

[Ron (Netherlands)]

With a gauge I measured my stash of German lenses/shutters. Some of the lenses/shutters have Imperial measures like some of the Compound and Compur shutters with an Ica Dresden label. I have a list of most of the Compur shutters with sizes of the lens tubes, but no list with the different Compound shutters [edit see table below] although they seem alike the later Compurs (they go up from no. 0 to no. 5).

One could have had the same shutter (e.g. the Compur no 2) with quite some different sizes of lens tube. Further Zeiss had the seizes of their barrel lenses indicated with a combination of letters and numbers, e.g. A VI 2 means a lens with a focusing device (A-Fassung) in barrel VI with a dept of 2 (I don't have a list to decipher the Roman and Arabic numerals)

You'll find detailed info on thread sizes below the picture on the flickr-site:


Vintage German lenses by Ron (Netherlands), on Flickr

...just found this listing of the Compound shutter in a French Zeiss catalogue:
At one point my measurements deviate from this list: my no. 0 Compound has an iris opening of 22mm.

[Ron (Netherlands)]

With regard to my post #32, from my lens/shutter combo's I could derive the following thread sizes:

Compound 0 M0.7
Compound 1 40 tpi
Compound 2 M0.9
Compound 3 M0.9
Compur 0 36 tpi
Compur 1 M0.6
Compur 1a M0.9
Compur 2 M0.9

Of course there should be Compound 1 and Compur 0 shutters with continental sizes, but mine - both stamped ICA Dresden - have a imperial thread size. Further the Compur 1 is an odd sized Compur since it is not mentioned in the list in post #32: mine doesn't have a tube size of 30mm but of 32mm.

Here you can find a list of different sizes of Compur shutters:

http://lostlabours.co.uk/photography...s/compur-1.jpg

[peter brooks]

Of course there should be Compound 1 and Compur 0 shutters with continental sizes, but mine - both stamped ICA Dresden - have a imperial thread size.

The VM seems to allude to this near the end of the section titled 'Threads, Lens mounting' -

In Europe, threads persisted as a different, partly metric series without so much standardization, except that the Deckel/Compur shutters forced a standard in some respect on their cells and flanges, but makers were slow to adopt them otherwise. The Leica used a metric diameter, 39mm but apparently a Whitworth form and pitch of 26 TPI perhaps due to tooling supplies. Many European firms were using machine tools made in the UK and used a mixture of metric diameters. and inch pitches as a result. Thus in remaking flanges, it is worth considering the use of Imperial Whitworth tools even when the actual diameters are metric.

Earlier in that section it is suggested that Ross were producing flanges for other manufacturers, and that their two sizes were so common as to almost be a standard (the sizes were investigated further by Mr Dallmeyer as part of the RPS standardisation process). The VM says -

The next meeting reported in 27/06/1890 p502, when Mr Dallmeyer announced that Mr Ross's 1.5in was actually 1.513in and his 2in was actually 1.98in. Thus they were not really 1.5 or 2in as claimed. Add in that other houses had no access to the originals, and relied on fitting their lenses to flanges purchased from Ross's and that these were not of hardened metal and wore while in use, and the cause of the general lack of interchangeability was obvious.

[Ron (Netherlands)]

The VM seems to allude to this near the end of the section titled 'Threads, Lens mounting' -

In Europe, threads persisted as a different, partly metric series without so much standardization, except that the Deckel/Compur shutters forced a standard in some respect on their cells and flanges, but makers were slow to adopt them otherwise. The Leica used a metric diameter, 39mm but apparently a Whitworth form and pitch of 26 TPI perhaps due to tooling supplies. Many European firms were using machine tools made in the UK and used a mixture of metric diameters. and inch pitches as a result. Thus in remaking flanges, it is worth considering the use of Imperial Whitworth tools even when the actual diameters are metric.

Earlier in that section it is suggested that Ross were producing flanges for other manufacturers, and that their two sizes were so common as to almost be a standard (the sizes were investigated further by Mr Dallmeyer as part of the RPS standardisation process). The VM says -

The next meeting reported in 27/06/1890 p502, when Mr Dallmeyer announced that Mr Ross's 1.5in was actually 1.513in and his 2in was actually 1.98in. Thus they were not really 1.5 or 2in as claimed. Add in that other houses had no access to the originals, and relied on fitting their lenses to flanges purchased from Ross's and that these were not of hardened metal and wore while in use, and the cause of the general lack of interchangeability was obvious.

Thanks Peter, for this additional info. Indeed tolerances weren't tight in the beginning and many times we will see German lenses/shutters with imperial threads.....
Further, fellow members who are not familiar with thread gauges, here is a sample - they cost only a few dollars and come in very handy when trying to find the thread pitch of your lenses/mounting rings:

These in combination with your (digital) calipers will help you find almost all the pitches and sizes of your lenses and mounting flanges.

[Ron (Netherlands)]

Retaining ring specifications for the many variations of the post WWII Ring set Compur shutters and the bigger Compound shutters (as from #3 with tube 7) can be found in the Compur Repair manuel:
https://www.suaudeau.eu/memo/rep/com...air/01-03.html