Originally posted by ivanvernon The Forum reviews do not appear to rate the K500 as extremely sharp, but these photos look more than sharp enough. I am wondering whether you used a tripod, and also whether you recommend this lens at the going prices. I've got the M-400mm f 5.6, and thinking about a little more reach.
Wide open sharpness is middling, IMO, but the fun really starts a half stop down. The lens' biggest bugaboo (besides handling) is chromatic aberration. It's copious at f/4.5 and while it decreases as you stop down it doesn't seem to ever really go away.
The K500 is bulky, heavy, and the focus ring is close to the camera, so IMO a tripod (or at least a monopod) is a must. The focusing action is OK, but not as smooth as other long tele lenses I use, like the A 400/5.6. But the lens is sharp, and mates well with the A 1.4x-L Rear Converter.
I've posted a bunch of samples here:
https://www.pentaxforums.com/forums/130-lens-sample-photo-archive/383864-smc...00-f4-5-a.html
Probably the shot that impressed me the most is this one of three young green herons. They were across the pond, some 70-80 yards away. I cropped this image by 75% and resized for web display:
I was only using a monopod, so had to keep the shutter speed up (1/750). A good performance by the K500, I think.
I think at under $500/shipped, the lens is a good value if you plan on using it with support, and don't mind dealing with the CA, and have a thing for big ol' glass. It certainly delivers in terms of sharpness and the ever-important fun factor.