Need help to find error.
My first attempt to photograph M45 with 135mm lens.
I focussed at F5.6 then stepped down to F8.
After processing in Registax 3 the stars look like rings.
The first shot is 17x2s, the second is 8x2s.
(Nikon D80, ISO 1600, Nikkor 18-135 lens)
Any hints very
