Originally posted by audiobomber I'm not surprised that the photo you posted is soft. 1/125s is simply too slow a shutter speed for a photo with this much movement.
The 55-300mm is not a soft lens, as most of the images in this thread show. It won't stand as much cropping as my DA*300, but if not cropped too hard, it is very sharp with amazing colour and contrast for a budget lens. If that is not your experience, then your lens is defective. Have you tried AF Adjust? That could explain your difficulties.
I was tracking the target to get background blur, so 1/125 is a decent setting for that (on the advice of an experienced photographer of horse racing), as is a little softness to be expected as I track a moving target. I actually found that image to be one of my better examples from this lens.
I have found mine to be soft even on tripod under ideal conditions, perhaps mine is defective (I bought it almost a year ago so I think perhaps I'm stuck with it, though). I've got my AF dialed in to the best result (and verified it this morning) and still it compares as soft to my other lenses. Comparing here to the 18-85, which is admittedly a top-notch lens, and the 35mm DA 2.8. These examples are at ~5.6 but I had similar results at f11.
I also don't find mine to "hunt" on AF like others have reported (at least not like my FA 100mm macro). Color and contrast are good, and sharpness is a bourgeois concept anyway, according to Cartier-Bresson (who shot with a Leica and thus found it easy to say). I just don't find this lens as impressive as my others.