Fitting a J12 to a Contax 1a

[Pyrs]

I am attempting to attach a J12 35 2.8 LZOS SN 7708857 to a Contax 1a and proceeding with caution.
All parts appear to fit with no obstructions and the rangefinder couples.
But the lens has sideways play,i.e. in the plane of the film, the connection does get a little more rigid as the lens is moved to close focus.
Can I ask if anyone has had any similar experiences with this lens?
The lens appears hardly ever used.
I would be grateful for any views.

 

[Xmas]

Pyrs

This is normal, on any Contax or Kiev body, you are lucky to not have focus probems/infinity lock problems. You need to mount it with care or risk damage to the rear optic, and always store with the rear cap.

If you use a filter you will need a hood, - a 49 mm step ring and an Oly (28mm) OM filter is what I use in this event.

If you inspect the rear optic if you have an exposed groundglass bevel you will need to paint this with acrylic black board paint very carefully - to reduce the tendancy for the lens to flare.

Noel

 

[Pyrs]

Thanks Noel for your reply.
The lens is as new, kept in caps and case and as yet no scratches or paint loss on the rear element.
Do you know where the slackness is, is it in the outer bayonet and can there be interference from the leaf spring lock on the normal focusing mount?
I have a film in the camera at present and don't want to open up to view for movement of the lens assembly from the rear.
If as you say this is the norm and the whole lens has slop, then how does this affect the sharpness of this lens on Kievs and Contaxes?
With best regards.

 

[Xmas]

Pyrs

Typically the lens can 'slide' parrallel to the film plane but has limited movement axialy, this will not affect the range finder or film plane sharpness. There is not any location mechanism. Many lenses wont focus freely or at all on some bodies, and Kievs are not worst offendor in this regard.

Many lenses can move sufficiently far away from the infinity lock that the lens will lock at infinity, this is only annoying.

Some of the lenses were not completely painted from new and you either need to verify that the rear bevel is painted or put up with risk of flare patches.

Many of the lenses dont focus sufficiently freely to be used with the focus wheel, without risk of wear. You can clean the helciod in situ without risk of damage, if it is waxy and stiff to turn, but this may not help as the lack of location and tolerances can prevent some lenses focus moving or even mounting completely!

Noel

Your photos should be good.