GL690 Lens Mount Question

[wjlapier]

I just received in the mail a GL690 camera with an earlier chrome lens. While waiting for the camera to show up I found a 65/8 lens and finder--same chrome. My question is about the mount. When mounting a lens the ring doesn't seem to turn the full 1/4 turn clockwise to the lens lock. It tightens up about half way. Is this normal? If so, what is the lens lock for then?

 

[Moto-Uno]

First question is if you've got the dark cloth in the film covering position. That seems to be necessary on mine. Also the ring only rotates around 60 to 70 degrees on mine to lock into position.
Regards,Peter

 

[wjlapier]

Dark cloth is closed when the lens is on. But the lens can be taken off if the cloth is open. That's why I was wondering if the lens lock is supposed to lock the lens so it can't rotate back to remove. Mine also rotates about 60-70 degrees too.

 

[Moto-Uno]

I can't remove my lens unless the dark cloth is covering the film ( open or closed is a bit confusing ) , and I can't reinstall the lens unless the film is covered by the dark cloth. Peter

 

[wjlapier]

So, looking at the lens mount and the lens, and then pictures on the web, it seems the lens should rotate a little more to lock the lens.

I can close and open the dark slide or whatever they call it. Closed the lens lock is loose, open the lock won't move. The lens can be removed with the dark slide closed or open.

I guess I'll have to keep that in mind. I'll run a roll through it tomorrow to make sure all is working fine, aside from the lens and the lock.

 

[Moto-Uno]

No way do I profess to be an expert on this camera, but being able to remove the lens
without the film being covered by the dark slide (unless the back is open) strikes me as though there's a safety interlock that's failed. Peter

ps; I know there are others on this forum very well versed on this camera.

 

[wjlapier]

I called Frank Marshman and he told me a few things to look into.

Basically, I think it's the mount. Two different lenses from different sellers not mounting all the way so the lock will engage suggest so.

I'm waiting for a call back from Frank to see what he thinks.

Could the mount be slightly bent--enough to prevent the lens collar from fully turning enough that the lens will lock?

These things are pretty easy to take apart for basic investigation.

 

[Spanik]

The interlock with the dark slide is only on the G690BL not on the GL690.

On the G690BL, when the dark slide is not in position, the ring turns but stops before the red dots align. You cannot push down the lock to remove the lens. If the dark slide is in position then the ring turns but stops before the red dots align. Then you push the lock down and you can turn the last bit of the ring and remove the lens.

The lens itself does not rotate. The ring doesn't turn a full quarter turn on mine either. It stops about 1.5cm before the lock.

 

[wjlapier]

Shoots fine. Took some quick snaps in my backyard with the 65/8 lens. I'd like the lens to be locked to the body, but for now it's fine the way it is.

 

[Moto-Uno]

^ Were you ever able to correct the loose lens problem ? Peter

 

[Dante_Stella]

Some chrome lenses from the original G690 (non-BL) era don't lock (seems to be a tolerance issue, since the cutouts used by the locking pin on the later cameras did not change visibly from chrome to black lenses). You might consider slightly enlarging the oval cutout on the lens' mount.

Spanik, the G690BL and the GL690 have identical locks. The difference is that the GL690 does not have the red indicator in the VF when the dark slide is closed.

The friction mount alone is plenty strong enough to hold the lens on - that's how it was done on the first generation of cameras.

Dante