M lens question

[dreilly]

I have in front of me a Summicron 50/2 collapsible and an Elmar 50 2/8 collapsible. There's a difference that I'm not sure should be there or not:

When I focus the cron, the front half of the lens does not rotate. When I focus the Elmar, the entire front half does rotate. In other words, I would have to hold onto the focusing ring to turn the aperture ring of the elmar. Normal, or not?

 

[rover]

Which version of the Elmar?

 

[dreilly]

The 1950s version produced, I believe, specifically for the IIIG. Not the new f2.8!

 

[klas.buren]

I've also encountered this and it made me write off the collapsible Elmar completely. I have no idea if it's normal or not though. Might just be me who did something wrong, but now I guess not.

 

[Hektor]

Hi dreilly, I have checked my lenses and can confirm that the elmar lenses do rotate and the summitars and summicrons do not rotate. It's due to a different method of construction of the focussing mount not the glass.

However, it does mean you must use round lens hoods with the elmars, whereas you can use square with the summitars/summicrons.

Also polarisers are difficult with the elmars but ok with the others.

Having said all this, the elmar is one of my favorites and has a really nice 'look' to the pics.

Regards John C. (Hektor)

 

[dreilly]

Oh. As the paper packets that wrap chopsticks say "That makes different."

Thanks for the confirmation.