Just got a canon 50/1.2 ltm... Does this seem right?

[arthurq]

Since it's ltm there's no "click" into place when I mount the lens. But shouldn't the focus pointer arrow be pointing up? Right now its about 20•degrees past top dead centre. Does that matter? I heard about people getting low DOF lenses "calibrated". Should I do that?

Thanks!

 

[Melvin]

That's the way screw mount lenses are designed. I can't remember why, maybe so an external viewfinder won't block the read out. As far as getting it calibrated, you should try it out for a while, taking into account any variables that might affect performance, like hand shake etc. One reason old lenses are so nice is that they were really well made, meaning someone took the time to calibrate them really well.

 

[Pickett Wilson]

Work with the lens for awhile. Focusing a 1.2 lens wide open with a rangefinder is an acquired skill.

 

[Mablo]

Since it's ltm there's no "click" into place when I mount the lens. But shouldn't the focus pointer arrow be pointing up? Right now its about 20•degrees past top dead centre. Does that matter? I heard about people getting low DOF lenses "calibrated". Should I do that?

Thanks!

It's supposed to be like that like all Canon LTM lenses. Enjoy!

 

[arthurq]

It's supposed to be like that like all Canon LTM lenses. Enjoy!

Thanks. I've only seen CV LTM lenses up to this point, and they all tighten down with the registration marks at TDC.

the focal distance scale is measured from the film plane and not the front lens element, right? I'm going to take measured out test shots.

 

[hans voralberg]

Most if not all "old" LTM lens mount that way 😀 And yes distance is measured from film plane.

 

[arthurq]

Thanks again. Also, what is the infinity lock for? And can anyone point me to a data sheet or manual for this lens?

 

[Melvin]

Thanks again. Also, what is the infinity lock for?

Good question

 

[gliderbee]

Thanks again. Also, what is the infinity lock for? And can anyone point me to a data sheet or manual for this lens?

I think that you should lock the lens at infinity before unscrewing it; otherwise it will go to the near-focus point and all forces will then fall on that small protruding bar that stops the lens from going farther; it might break off if too much force is put upon it.

Stefan.

 

[Rogrund]

Not a data sheet or manual, but some great info on the lens:

http://www.antiquecameras.net/canon50mmf12ltm.html

 

[johannielscom]

I wrote a pictorial on cleaning this lens yourself, on my website. Not for unexperienced filk, but might be nice to see the insides of your new lens?

Enjoy your Canon!

 

[braver]

It's supposed to be like that like all Canon LTM lenses. Enjoy!

I was told it's that way so you can see the aperture setting when peering into the bottom right corner of the viewfinder. It's a neat trick really, just not all that useful 😎

 

[John Shriver]

The one- to two-O'clock indexing is so you can see the focusing scale around the nose of a VIDOM, VIOOH, or similar finder. You sure can't see it through the corner of a screwmount Leica viewfinder, and that's where they first chose that indexing.

 

[gordonb]

Thanks again. Also, what is the infinity lock for? And can anyone point me to a data sheet or manual for this lens?

Mike Butkus has the catalog for the lens for free download.