• Welcome to Photrio!
    Registration is fast and free. Join today to unlock search, see fewer ads, and access all forum features.
    Click here to sign up

Series VI adapter threads?

Steve Goldstein

Subscriber
Joined
Jul 8, 2007
Messages
1,827
Location
Northeastern US
Format
Multi Format
Kodak (and others) made push-on adapters for mounting Series VI filters on all sorts of threadless lenses. These had two parts - the push-on piece with a female-threaded cavity, and a male-threaded front ring that held the filter in place in the adapter. I have two questions to which I’ve been unable to ferret out answers:

1) What is the male thread size on the front ring? I’m most interested in Kodak adapters as those are what I have.

2) [Extra points] Did all manufacturers use the same threads?

Thanks in advance.
 
It's 44mm. I managed to get my hands on a Heliopan adapter 223 44mm to 49mm step up ring. I got it to use 49mm filters with Kodak Series VI filter adapters. This allows me to use modern filters on my old 2x3 Series B Graflex and my 4x5 Crown Graphic with the 135mm Optar.
 
Last edited:
I believe that Series filters are on imperial standards. Checking my VI ring with calipers, it would be a 1.75"x32tpi thread. Roughly 44.5x0.8 in metric.
 
The threads are interchangeable between Kodak, Tiffen, Harrison and most if not all american made adapters. And yes they are inch threads.
 
OAPOli said:
I believe that Series filters are on imperial standards. Checking my VI ring with calipers, it would be a 1.75"x32tpi thread. Roughly 44.5x0.8 in metric.
Click to expand...

I just remembered that I had an old Bishop Graphics loupe with a measuring graticule hanging around from back when I did PC boards in the 1980s. It's a bit hard to see the threads given the shallow depth of field, but they appear coarser than 32tpi. The spacing seems closer to 3/64" (21.33 tpi) but as that's a very weird number I suspect they might be 24tpi. Clearly not 32tpi as there's a 1/32 marking on the graticule.
 
Disconnekt said:
A site called Pacific Rim Camera has a pdf on their site showing Kodak booklet from 1946 that shows lens Series adapters/diameters & lens accessories:

www.pacificrimcamera.com/rl/00191/00191.pdf
Click to expand...

I've looked at that document and, unless I missed it, it seems to tell everything there is to know about Series adapters except the thread information I'm looking for.
 

That's odd. I'm using a 32tpi screw as a thread gauge and it seems a bit coarser (and with taller threads) than the ring. I would guess it's actually 36tpi.
 
Hmm. Tomorrow I’ll see if I can score a bar of soap with the threads to get a more accurate visual measurement.
 
You must log in or register to reply here.
Menu
Log in
Register