M40x0,75 which mount?

[supahmario]

can anybody tell me which mount this is?

M40x0,75

i already searched it but i could not find anything that explains it.

[Attila]

Put to search bar of Google "Praktiflex M40" I have one camera+matched Biotar 58mm f2 lens.

[no-X]

Night Exakta and late models of VP Exaktas (post 1933). There are also other systems using this screw-mount. However, if the lens has only aperture and not focusion ring, it's 90% the VP/Night Exakta lens. These exaktas had focusing helicoid build-in the body.

[supahmario]

is there any cheap way to mount it to canon-ef?

[no-X]

I have no experience with praktiflex lenses, but as for the VP Exakta lenses, you can use bellow or the shorter focusing helicoid from Alex + adapter ring (M42 -> 40x0.75).

[kds315*]

That was common for lenses which were planned to fit into a size #1 shutter many years ago.

Leitz used it for instance for their special Milar, Summar and later Photar series of macro lenses used in the Aristophot system, as well as Polaroid for their MP4 macro stand with the Tominon series of macro lenses (17 - 135mm focal lengths).

And no, there is no direct fitting adaptor to Canon EF, but one could be made of course by someone knowing to use a lathe ("Drehbank" in german).

[supahmario]

thank you very much klaus!

what is the register of m40 mount?

i read (dont remember if it was here) that there could be a way to adapt it via special exakta extension tubes. but i didnt understand it completly.

[supahmario]

anyone ever tried to adapt this via using tape around the mount fit it to m42 screw mount? this would be not the most precise way, but it could be a way, or not?

[no-X]

I use my Night Primoplan this way I wrapped the thread with the plastic food foil and inserted into M42 extension ring. It works:

http://forum.mflenses.com/night-flowers-t16763.html

[kds315*]

well I would only do that with really precious lenses which cannot be replaced.....

[supahmario]