Originally posted by dugrant153 I also have the DA*16-50. On the K100D, it consistently mis-focuses, back focuses, front focuses, soft focuses... just not SHARP focus. It was frustrating cuz the picture turned out great but the focus would be off or something. On the K200D, the DA*16-50 now smartens up. I think the SAFVOX AF on the K200D is more well tuned for the DA*16-50 as the DA* lens now takes sharp pictures and only messes up due to user/photographer's error!
So if you have the K100D and plan to use it for a while longer, buy the DA*50-135 (But test it first) and upgrade your body before going for a DA* 16-50.
Funny, I have a k100D and K20D, and both DA* zooms. The 16-50 is almost always on the K100D since it focuses perfectly and is much more sharper on it than on the K20D... the 50-135, well it's tack sharp on any model!
Anyway, back to topic, the 50-135 is great for concert photography. Paired with a K20D, perfect! In fact a fellow photog who used my cam + lens combo once, together with his D300 + 28-70(?)/2.8 combo was blown away! He now borrows my cam+lens at gigs whenever I perform since it blows his D300 away! (Maybe it's the photog, I don't know... but still... score one for Pentax!) Here are some samples:
All at ISO 1000... amazing sharpness and noise control!