Wollensak enlarging lens thread spec?

[tedr1]

My enlarging lenses are all 39mm thread except one vintage Wollensak, a 135mm Raptar, that measures 40.5mm (one and nineteen thirty-seconds inch!) can someone please tell me what the thread standard is for this Wollensak, diameter and pitch?

 

[jeffreythree]

Interesting, all of my Wollensak enlarging lenses are 1-3/16" 48 tpi. Does it say Enlarging Raptar or just Raptar?

 

[tedr1]

Enlarging Raptar

 

[jjphoto]

Try this, http://www.cameraeccentric.com/html/info/wollensak_16.html, but I've never been able to work out the relationship between the different 'No. X Iris Diaph. Barrels' and actual thread diameter and pitch. If you work it out please let me know because I'd like to update my own table with this information.

 

[tedr1]

Thank you. Yes the "iris diaphragm barrel" designation hints at useful information elsewhere, but I don't see it. I notice page 2 is missing and we have extra page 5A, but no page 8. Close, but not quite there unfortunately. My need is not pressing, perhaps someone with the knowledge will show up?

 

[Ian C]

I checked a Wollensak 135 mm f/4.5 Enlarging Raptar. The outside diameter of the mounting thread is 1.558” and the pitch is 30 threads per inch. The diameter is 1 9/16” (1.5625”) minus 0.0045” assembly clearance.


Thus the nominal size is 1 9/16” diameter by 30 threads per inch (60º Unified V-thread).

 

[tedr1]

Thanks Ian, mystery solved

I come from the world of 39mm enlarging lenses (I'm an immigrant from the UK) and it seems likely that if Wollensak is typical of American lens makers then there were lots of different threads and people in the past had a lot of different lens panels.

 

[chip j]

Where can I get an adapter for my 50mm Enlarging Raptar??

 

[ic-racer]

Where can I get an adapter for my 50mm Enlarging Raptar??

Which enlarger? Most enlargers have some option for mounting lenses with a flange or retaining ring. SK Grimes can likely make them for your lens. http://www.skgrimes.com/products/mounting-flanges/u-s-a-stock-flanges

 

[chip j]

Thanks ic. All my enlargers have Leica 39mm screw-mount TUBES.

 

[ic-racer]

In that case I'd look for a 39mm mount 50mm enlarging lens. There should be millions of them out there.

 

[mgb74]

I tried to mount a couple of 135mm Raptars yesterday and found they wound not fit in Beseler boards intended for 39mm lenses. I wasn't able the measure the threads. Reading this, I wonder if a 39mm to 40.5 step up ring would work. I don't know the pitch on a filter step up ring.