Sigma 24mm Super Wide II

[Ariston]

I bought one of these and the focusing feels "sandy," for lack of a better description. Should I be worried about this? Should I try to open it up and blow it out?

 

[John Koehrer]

I doubt blowing it out will help. Sandy or gritty is normally sand or grit in the grease of the helical.

 

[Ariston]

I doubt blowing it out will help. Sandy or gritty is normally sand or grit in the grease of the helical.

Will that damage the lens, or just annoy me?

 

[John Koehrer]

It will eventually cause excess wear to the helical which may loosen the focus to a point where that too
may annoy you. Depends on the quality of helical materials.