Yashica to QBM adapter ?

[Anaxagore]

Hi, is there a known Yashica to Rollei QBM adapter? When googling for that, I find many topics where people want to use a QBM lens on other systems, but in my case I wonder about the possibility of using a lens with Yashica mount on my Rollei 3003..

 

[Heritage Cameras]

Hi, is there a known Yashica to Rollei QBM adapter? When googling for that, I find many topics where people want to use a QBM lens on other systems, but in my case I wonder about the possibility of using a lens with Yashica mount on my Rollei 3003..

Unfortunately not.

Assuming you're talking about the Contax/Yashica mount (and not M42 screw or Pentamatic) this has a flange focal distance (FFD or register) of 45.5mm, while the Rollei/Voigtlander QBM mount is 44.6mm. This leaves less than 1mm for an adapter if you want focusing to infinity. Such thin adapters are sometimes possible, but only where the lens bayonet is much smaller in diameter than the body one, which isn't the case here.

https://www.graphics.cornell.edu/~westin/misc/mounts-by-register.html

It may be possible to replace the mount on the lens and retain infinity focus. You'd need a donor mount from another suitable lens, plus some DIY skills and tools or cash for an expert conversion. 3D printing a replacement mount is also a possibility. You'd lose automatic diaphragm and full aperture metering, but stopped down metering would work in manual and aperture priority auto modes. Here's a commercial example of how Zeiss C/Y lenses can be modified to fit onto Nikon cameras:

http://leitax.com/Zeiss-Contax-lens-for-Nikon-cameras.html

Depending on the resale, collectable and/or sentimental value of the lens this may not be worthwhile... it would usually be simpler and often cheaper to sell your lens and buy one in Rollei fitting.

Hope this helps.

ps. I just noticed you said "lens with Yashica mount" and not "Yashica lens". If you have an independent lens in Yashica/Contax fitting it might have an interchangeable mount (Tamron Adaptall for example). If you confirm exactly what the lens is I may be able to provide more specific advice.

 

[xkaes]

It's possible that some company sells a C/Y to QBM adapter, but it would likely have a built-in glass element -- to increase the focal length of the lens, thereby allowing for infinity focusing. That said, it's not too likely simply because the C/Y was not one of the top five mounts, and neither was the QBM. Try companies like PHOTODIOX:

https://fotodioxpro.com/collections/lens-mount-adapters

 

[Anaxagore]

Thanks for the answers.. it is not my lens, only one for which I have looked for a long time, quite rare in QBM mount. Here is the picture shared by the seller. As there seems to be little hope for conversion, I think I will pass on the sales offer..

 

[Heritage Cameras]

Thanks for the answers.. it is not my lens, only one for which I have looked for a long time, quite rare in QBM mount. Here is the picture shared by the seller. As there seems to be little hope for conversion, I think I will pass on the sales offer..

It's hard to tell what it is from that picture... there's no sign of an auto diaphragm lever so is this a manual lens of some sort? There seems to be a lens release on the side which is wrong for Yashica.

 

[xkaes]

That "lens release" on the side might be an interchangeable lens mount release (Y-S?) with the actual lens release button on the camera body.