I tested the lens today, which is bought from a fellow Pentaxian. I looked at all the pictures in magnified mode, and I am in alignment with the other reviewers of this lens. This is indeed a sharp lens. http://www.pentaxforums.com/lensreviews/SMC-Pentax-F-Star-300mm-F4.5-Lens.html You can get more information from the URL attached.
Sight - the sensory perception results in an image. A series of image creates a story. The story invokes an emotion. The emotion surfaces an experience. The experience provokes a judgement. That judgement brings about an insight. Life is indeed a cause and effect - a sight to insight. Learn from the gift of sight daily. Share your gift of insight to everyone.