[TrailRunner]

Hi all,

I'm thinking of picking up a Sigma 400 F/5.6 (not sure which exact model it is, as the ad doesn't say - HSM or not HSM. Guessing it's non HSM), but came across this rather scary bit on Photozone, "The tested sample had no real issues on the EOS 350D but older samples with an old firmware may even lock up your camera. This is especially likely for the older variants with a conventional AF motor (non-HSM)."

Can anyone speak to this with regards to the K-3? "Lock up your camera" sounds very very scary...

Thanks!

[Digitalis]

Sigma 400 F/5.6

To the best of my knowledge there are several versions of this lens - the two manual focus versions are to be avoided: optically speaking they are just atrocious. The Sigma 400mm f/5.6 APO Macro on the other hand is said to be a superb lens optically, physically it is a beast of a lens.

Can anyone speak to this with regards to the K-3? "Lock up your camera"

Canon cameras are more dependent upon electronic communication between the lens/camera than pentax DSLRs are. I have personally never heard of a Lens locking up a Pentax DSLR.

[UncleVanya]

I have the plain old 400mm Sigma AF 5.6, it is a screw drive lens and works fine on my k50 but it is NOT a great lens. My copy has done optical glitches due to either fungus or deteriorating lens cement. The lens is charcoal gray and can not be disassembled without resorting to making tools. It is all in all an interesting lens with less IQ than you would get cropping a 55-300. It is light and handles nicely however which makes the IQ a shame. I can post a few pics if needed.

Understand that this is a very hard lens to repair. Parts are non-existent, Lens isn't designed to be repaired either.