mounting Rollei bayonet on K mount

[orly_andico]

i got a Rollei Planar 50/1.8 Singapore for the astounding price of $10.

i knew there would be lens registration issues on Pentax (I thought I would unbolt the bayonet mount, and screw in an M42 mount).

But I've discovered to my surprise that the Rollei bayonet fits (but does not lock) on the K mount. But it would be easy to secure. (not to mention that the mirror clears the rear part of the lens.... tested using the "test by destruction" method)

The problem is that when mounted this way, the MAXIMUM focusing distance is around 1.5 meters.

Any ideas? (hopefully reversible)

p.s. I saw some Rollei 200/4 Tele-Tessars for $40 in KEH. They seem to be good cheap user lenses...

[luisalegria]

The problem here is that the Rollei mount seems to have a shorter register than M42/PK.

It may be possible to adjust the focusing mount to get the thing to screw in further on the helical, I have done this on some long lenses, but its unlikely that a 50mm would have much if any scope for that.

[Stan]

> screw in further on the helical
A way to go, if you are OK with taking the lens apart and putting it back together.
I've done this trick even in Konica AR 40/1.8, which is a pancake and has only 27mm of total length. I moved it for healthy 3mm!

[orly_andico]

@luis, you are right.. the rollei mount is actually a bit more than 1mm shorter. i expected this... even if i don't get infinity, if i get 10 meters that is good enough for me