Yea, switch is seated correctly. Contacted SRS Microsystems today. They will replace the camera, so fair play to them. Fingers crossed the next one will be ok. Thanks for the reply.

Hi everyone,

I tried using my Sigma 105mm and 180mm macro lenses on my new K5 today. But the screw drive mechanism does not marry up correctly. All i get is a grinding noise when i try to focus. I've noticed that the drive does not protrude as much in comparison with my K10 & K20. Any one else had this problem ? At any rate, the camera has to go back. I just hope the replacement wont be the same... !

Cheers.

Hello everyone,

I’m considering upgrading my lens, a Tamron SP 200-500mm f5.6 (Model 31A). I’m looking at the Sigma 50-500mm f4-6.3 EX APO. Firstly is the auto focus worth it (lens used for wildlife) ? Reviews I’ve read say that at f6.3 the auto focus is slow or useless in all but direct sunlight. My current lens is a constant f5.6 throughout the range. Secondly are the optics any better ? Is it worth spending the £600+ ?? Any thoughts are welcome, thanks.