Stephen Paul wrote:
Thanks for the clarification... all though, I have to say, the pin cushion
in my wife's sewing kit is oblate. I also think it interesting how the
description of a curved line at the edge, gives the illusion that the bowing
out is a result of the center of the line getting thrust beyond where it
should be, rather than the corners of a square getting "sucked in" toward
the center.

It amounts to the same thing. There is no "officially correct"
magnification, so the two interpretations are equivalent.

You do realize of course that from your description, one might get the
impression that you have some experience putting square pegs into round
holes. g

I might, rabbit, I might.

Brian Tung
The Astronomy Corner at http://astro.isi.edu/
Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/
The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/
My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.txt