contax iia - lens "play"

[edhebert]

hi all-

 

I've got a contax IIa fitted with a sonnar 50/1.5, and the

lens/camera coupling has a small amount of rotational and

axial "play" to it. Not enough to affect optical or functional

integrity, but enough slop to annoy me in the "feel" department a

bit. When focusing or adjusting aperture, there's a slight (1 or

2°) "float" before the threads engage.

 

The helical itself seems solidly coupled to the camera. The play is

between the helical and the lens itself. It seems like there's an

ever-so-slight gap between the lens' locking tab (the tab with the

red alignment dot on it) and the camera body's corresponding tab

recess (the release spring where that tab sits when locked and

mounted). Tough to describe, but I hope you get what I mean...

 

Since this is the only lens I own for the camera, I can't test

another to see if this is normal. Is a small amount of play to be

expected on this camera? All other moving parts are so precisely

machined on this camera that this one quirk seems very atypical for

the camera.

 

If it's not normal, could anyone suggest a proper adjustment to

tighten the coupling of lens to camera body so that this slop is

mnimized?

[furcafe]

In my experience, a little bit of "play" is within the normal variation between Contax RF 50mm lenses. If you want to adjust the lens's locking tab, you can bend it a tiny bit downwards (i.e., towards the camera body) to make a tighter fit.

[marco_vera1]

I tiny bit of rotation of the lens in it's mount, due to wear of the lens mounting pin (both on the body or the lens)can be present.

 

You should not have any axial movement.

 

You should not have any play between the lens mount and the focusing knob.

[mike_elek]

It sounds like what your describing is that the tab on the lens is slightly narrower than normal and therefore rotates slightly when mounted.

 

This small amount of play while annoying shouldn't affect the focus.

 

The next question is whether the lens tab is in fact too narrow or if the notch on the helical is too wide from having the lens inserted and removed repeatedly and harshly. That is, if the camera was used hard.

 

If the notch is too wide, and this were my camera, I might fill the gap with some metal solder (not electrical solder) and then file it down to the correct width and then be very careful about inserting and removing lenses.

 

Or maybe I wouldn't worry about it.

 

Or I might ask if anyone had this helical arm and replace it.

 

Or I'd buy a second body. Oh wait -- I've done that too many times already.