Quote Originally Posted by Jack Flesher View Post
If you google "comatic flare," "spherical aberration" and "astigmatism," I'm sure you'll find several references and some should have diagrams and examples.
I wrote a long reply to your previous post but lost it all - my ISP is on the blink today.

However I have a prima example of coma here - maybe it works this time.

This image (hopefully) displays both astigmatism and coma, but coma is by far the dominating aberration. The result is just about the opposite of "swirlies".