I wonder if some of you more technically oriented folks could tell me if I have a problem with my Pentax 55-300 mm lens. In the photo below, Half Dome is about two miles away, and is in focus. But the mountainside behind it looks slightly out of focus to me, and it's about 3.5 miles away. I noticed in focusing on Half Dome that the focus ring was not quite at infinity. Later that evening I took a picture of the moonrise by setting the focus ring at infinity, since it was too dark to use autofocus, and noted that the moon seemed slightly out of focus, but maybe it's just a resolution issue.
About a week before this trip, I dropped the lens from 2-3 feet onto a hard floor. When I put it back on the my K-7, it seemed to work normally, but now I'm wondering.
Any thoughts?