Strange stiffness when moving focusing ring

[Bobby]

Advertisement (gone after registration)

I have a Summicron 50mm f2 (new). I noticed that when I move the focusing ring fast, I can feel the transition from 1m to 1.2m focus. It's like changing aperture but a lot smoother.  

 

Sometime I can feel it even when I move the focusing ring slow. 

 

Is it normal, or should I have it repaired?

[harryzet]

exchanged,not repaired

[Advertisement]

The Leica Q3 is available for pre-order at B&H Photo Video and Adorama

[pico]

I have a Summicron 50mm f2 (new). I noticed that when I move the focusing ring fast, I can feel the transition from 1m to 1.2m focus. It's like changing aperture but a lot smoother.  

 

Sometime I can feel it even when I move the focusing ring slow. 

 

Is it normal, or should I have it repaired?

 

Does it make any change in lens performance?

[Bobby]

no change in lens performance. However, it does not feel normal and I know Leica stores are very kind when it comes to repair or replacement

[jdlaing]

no change in lens performance. However, it does not feel normal and I know Leica stores are very kind when it comes to repair or replacement

If you exercise it a little bit it may smooth out. It probably sat a while.

[Eoin]

Check the focus cam on the rear of the lens, there could be a piece of dirt stuck to the cam surface giving you that aperture dent feeling.

Also check to see if the feeling is there when the lens is unmounted, if not, it could also be a slight tight spot on the camera focus cam

[TomB_tx]

Advertisement (gone after registration)

I bought a new Summicron a few years ago, and it was a bit uneven in "feel" as it focused. The more I used it, the smoother it got, and in a short time it became extremely smooth and easy to use.

[250swb]

It's certainly something you could solve for yourself while sitting in front of the TV watching your favourite programme. Twiddling the lens back and forth shouldn't interrupt your enjoyment and it will settle and spread the grease (if it is the grease that needs settling). But before even doing that you could also push the focus arm back and forth to see if the obstruction is the camera body itself, but do it gently. Another consideration would be does the camera body focus at 1 meter (you don't say what it is), the change in feel may simply be the lens naturally coming off the cam?