Strange Lens

[Trius]

Last month I picked up a 135/4.5 Aetna Actinar lens in barrel mount. The only web references I've seen refer to it as an enlarging lens, but this one has a bayonet mount. It appears the bayonet mount fitting is added on to the lens, as the rear lens element is quite recessed. The rear (bayonet) section is the same style/manufacturing as the rest of the lens, so this isn't a 3rd party hack.

Not having an M mount body or fitting to testing, is it possible this lens was made for fitting onto a Visoflex? There's no focusing helicoid in the lens, so it couldn't really be used as a 135 taking lens directly on an M body.

Has anyone seen this configuration? I looked for the specs of the M mount (configuration, dimensions, etc.) and couldn't find anything. So, any help is appreciated.

Oh... why did I buy it? BECAUSE IT WAS THERE!

 

[Ash]

It could always be a enlarger-specific mount. When I was looking through the draw full of strange old enlarger lenses in Peter Gilberts there was a time when no one thought of having a 'standard mount' so every possible flange size and configuration was used. Maybe its even for a Leica Enlarger. Leica had those enlargers that you can use their normal lenses on, but I only saw the advert for a screwmount version I think??

 

[Trius]

I've never heard of a Leica enlarger with other than the 39mm screw mount. Others on APUG have suggested T mount or Exacta. Some sort of bellows mount is likely, but I'm just curious. With the correct adapter, I could use it on my OM bellows for macro work.