Wollensak Veritar Thread Pitch Help

[tgtaylor]

Hi all,

Does anyone know the thread pitch and filter size on a 14" Wollensak Veritar lens? I took it to a local camera store yesterday and tried to measure it with their caliper which was a little broke. The diameter appears to be ~100mm and the pitch on the threads is much narrower than the pitch on the 610mm Apo Nikkor process lens that I brought with me for the same purpose. The Nikkor has a filter diameter of 95mm and we screwed in a circular 95mm filter which they happened to have. They didn't have a 100mm screw-in filter nor any step-up/down rings in that size so I'm not sure what filter size it takes or if any filter ring will thread on the lens. I use this lens for soft focus images and need to use a ND for outdoors shots when the sun is out (with heavy fog lighting I can get by without one). Currently I'm placing a 100mm 3-stop Schneider rectangular filter by hand against the front of the lens but would like to use a Cokin X-Pro or similar but would like to avoid the cost of the Universal Filter Ring: http://www.bhphotovideo.com/c/product/168533-REG/Cokin_CX499_X_Pro_Universal_Adapter_Ring.html Any input or suggestions is appreciated.

Thomas

[Tracy Storer]

Bring it over, I've got english and metric thread pitch guages. We SHOULD be able to figure out what you need. Sending PM with my phone number.

[jnantz]

hi thomas

i also have a 14" veritar but i have no idea what
the pitch or thread or size is, i am sorry i could not be
of any help -

good luck !
john

[Tracy Storer]

OK, the OP came over with the 14" Veritar lens, and it looks like it is a 4" - 40. That is to say, the male filter thread SHOULD BE nominally 4"od, but in reality will be a bit less, and 40 threads per inch, which is a fine thread, as filters generally are. My 40 tpi guage seemed to fit the thread perfectly

The ID of the female thread was 3.941", both crests of male threads and roots of female threads are truncated, so, it's hard to say for certain, but most if not all lens threads I have seen (for flanges as well as cell mounts in barrels) are "truncated" versions of some sensible fraction or whole number. That is on what I am basing my surmise that it's a 4" - 40 tpi thread.