[bojan]

Hi Adrian,
Thanks for this, however I knew about this s/w.

My problem here is that there are no adjustments for collimation for this lens.
I even had a theory/explanation at some stage that the spacer ring between two front correction plates was bent, therefore of un-even thickness, thus causing the astigmatism of the system after relaxing (because it expanded), but after replacement with new one, there was no improvement.
That is why I wanted to do some simulation of similar system to see if a problem like this could be caused by misalignment at all, and what that misplacement should be to produce the outcome of such magnitude...

BTW,
have you tried to use yours as astrocamera? I would be interested to see the test pics :-)