This was how images looked in my Ca K PST originally. It shows bad astigmatism. Obviously the word 'focus' is used loosely here ! I didn't know if the astigmatism was caused by the 40mm objective, the pentaprism (focus mechanism in the PSTs), or the blocking filter (BF), but my first step was to check and see if the pentaprism was out of alignment. It was : it was 8° out