The purpose of these summaries is to give a reader an overview of the Pentax lens lineup, identify its gems and dogs, and point to some of the reference sites listed on the right in case further research is required. Pentax is one of the rare manufacturers of photo-equipment that maintained backward compatibility with its lenses that allowed even an old screwmount Takumar to be mounted on a new AF camera. Therefore, it's very difficult for a single person to accumulate the knowledge and experience needed to compare a pair of lenses in Pentax's extensive lineup. Thus, this summary, almost entirely, is based on the collective opinions and combined experiences of the members of PDML. I've learned a lot from many dedicated members on this list in the past couple of years, and I've decided that it's time to summarize and share the knowledge, promote Pentax photo-equipment, and gain some followers along the way. You will encounter a few gaps in this summary due to fact that some lenses haven't been discussed as much as others, but as time goes by, I plan to fill these gaps.