Originally posted by StDevious Also the pics seem really soft at 300mm. Not sure if they are a bit out of focus because I had the AF.C on instead of AF.S
Any ideas ?
Or maybe the softness could be caused by the fact that YOUR SUBJECT IS MOVING AT MACH 2!!!
Ha ha, just kidding. But seriously, you may want to do some test shots of a stationary subject with your camera on a tripod to determine how sharp 300mm really is. But for the most part, you shouldn't expect too much sharpness out of an inexpensive 300mm zoom lens at its extremes. I've had a Pentax DA 55-300mm, and Tamron and Sigma 300mm zoom lenses, and none of them have been all that sharp at their long end. Tamron does have a new 300mm zoom lens (Tamron AF 70-300mm f/4.0-5.6 SP Di VC USD XLD) that actually is pretty sharp throughout the range, but unfortunately it's not available for Pentax. Bastards!
As far as the fringing on highlights, I would say it's probably the lens, assuming you haven't seen this with all your other lenses mounted on this camera. I have a Sigma 50-150mm f/2.8 HSM II that is a wonderful lens with outstanding image quality and sharpness, but its big weakness is color fringing along blown-out highlights, just like in your picture of the jet. The good news is that people always say it's easy to correct the fringing. The bad news (at least for me) is that I never seem to have much luck when I try correcting it, so I've stopped trying.