Steve gave me the one of the best ideas I have ever found. At f295 was making teleobjectives for 35 mm camera with tube and collected diopters but no information on diopters and fl.

I found it suprising , when lens designers spend years to make a lens design , your design is such simple and elegant.

I am still looking for an answer , how cylinderical lens elemnents behave on image ?

Umut