Sigma 30mm f/2.8 DN Art - Rattling?

[beercan]

Hi all,
My sigma 30mm f/2.8 DN Art lens rattles when it is both separated or attached to my A6000; however once the camera is switched on the rattle stops. If you look in the lens from the rear and shake it you can see something moving back and forward.
I assume this is related to the auto focus, but was wondering if this behaviour is normal?
Thanks!

 

[Brazo]

Yes it’s normal. It has a floating element which only becomes alive once powered on.

 

[beercan]

Thanks; that's reassuring to know.
Cheers!

 

[Cagey75]

Yup, completely normal - the 19mm and 60mm do the same, the 60 for definite as I had that one [excellent lens for the money btw] but afaik the 19 also does it.