stiff focus on cron' c

[shimo-kitasnap]

Anyone know how to loosen up the focus of one of these (40mm summicrons?)

thanks,

 

[ferider]

Take it apart and re-grease it. Not difficult, the helix separates from the lens barrel when you take off the ring from the back with a spanner. Then you'll see how to separate and grease the helix.

Roland.