The pentax pf ca35 allows you to connect a pentax k mount digital slr to your pentax pf series spotting scope to create a super telephoto lens the adaptor has a total of 5 lenses in 4 groups all of them fully multi coated resulting in brilliant edge to edge sharpness and true colour image reproduction the pentax pf ca35 allows you to connect a pentax k mount digital slr to your pentax pf series spotting scope to create a super telephoto lens