Bolex Iris Vignetter

[BAC]

I have a Bolex Iris Vignetter that according to Bolex literature is supposed to work on all 8mm lenses. I have almost every 8mm Kern lens and it doesn't fit on any of them. The Iris Vignetter has small threads on the end that are supposed to attach it to the front of the lens but they don't match any thread on the front of the lenses. Some of the lenses have threads deep inside them that are close but they don't match. The threads are about 15mm, slightly smaller than a D-Mount thread. I inspected the threads on the Vignetter and they appear to be in good condition. Am I missing a part or is there an adapter needed to attach it? Any help would be appreciated.

It's the last item listed on this page of the Bolex Collector site:
http://www.bolexcollector.com/accessories/filter50.html
It's definitely the one from the 1950's, not the one from the 1940's on the previous page.

It's also listed on the bottom of page 4 of this brochure:
http://www.apecity.com/manuals/pdf/bole ... ochure.pdf

[sciolist]

Kern-Paillard D-mount lenses have a 21mm attachment size (the exceptions are the 13mm f0.9 and 36mm f/1.8 Switar lenses which are 28mm). Even the earliest Kern-Paillard lens I've got on an L8 has a 21mm attachment size. I've got the version of the iris vignetter made for Kern-Paillard C-mount lenses with a 32mm attachment size (a collar on the back unscrews reveaing a slightly larger diameter thread that may accommodate series V filter adapters). The deep-set threads in some lenses are used to secure wide-angle conversion lenses (Hyper Kern-Paillard and Hyper Cinor).

[BAC]

Thanks for the response Sciolist. The one I have does not unscrew to reveal larger threads. It seems like it should attach deep in the lens like you described but the threads just wont match up on the lenses that actually have threads in there. If I loosen 3 very small screws at the base of the collar it can be removed but there are no threads in there. With the collar off it's closer to a series 4 size opening than anything else. Maybe I can find a series 4 adapter ring that will allow me to attach it with the 3 small screws. It would be difficult to operate this thing without it securely attached to the lens.