Mount question for oldies.

[swanseamale47]

Back in the day as well as m42 , Olympus and so on there was a T mount, There was another often for lens gadgets like macro atchments and fisheye, this looked a lot like a stepping ring with a filter size on one side and the gadget the other side. What where they called, it was a common mount not item specific/
My memory is staring to go I think....

 

[Box Brownie]

Lens reversal ring(s) ?

Google Search

www.google.com

Article here

Working With a Reverse Ring For Macro Photography With High Magnification

Macro photography is a fun thing to do. With a normal macro lens, you can reach up to a 1:1 magnification. With a couple of extension tubes, it is possible to boost the magnification a bit, but not much. If you are interested in higher magnifications, you could try a reverse ring first. I do...

fstoppers.com

 

[AndrewFlannigan]

... this looked a lot like a stepping ring with a filter size on one side and the gadget the other side.

I think that's what it was called: a stepping ring. They came in both step up and step down versions.

For clarity's sake: we are talking about a female thread on the "gadget" side and a male thread on the lens side?

 

[swanseamale47]

I think that's what it was called: a stepping ring. They came in both step up and step down versions.

For clarity's sake: we are talking about a female thread on the "gadget" side and a male thread on the lens side?

Yes female on gadget side. ( identical to stepping ring) But I seem to remember it had a specific name and size and thread on the gadget side. You bought a "xyz" to 49mm or whatever? If my memory is right the thread pitch was very fine on the femail side.
Mind it was a LONG time ago
The gadget I'm thinking of in this case was a fisheye conver for a camera lens, you got a full circle fisheye effect with I think 28mm and a very wide 15mm ish with a ton of distortion on a 50mm.
I've got one here somewhere, if I can find it I'll bung up some close up shots, throuble is the builders have everything moved, hidden or crammed in one room so finding my old gear is a nightmare. No way can I get near a film camera (not that I use them).
Thanks Andrew,.

 

[swanseamale47]

It was a series 7 mount, Actually a very course thread (so much for my memory)

 

[GreenNinja67]

T2 mount?

I still use them for a slide duplicator and to attach my camera to my telescope

 

[zx9]

Usually denoted Series VII , I recall that Leica were one of the later users for some of their filters.
Just looking now, there are lots of Leica and other Series VII filters on Ebay.