Re: [APML] Reducing Coma

["Bobby Middleton" <bobm@koyote.com>]

> Roland Roberts wrote:
> > it.  I was just hoping someone could chime in with personal experience
> > or a knowledge of optics that said "yes, it does/sometimes helps."

It will definately help. It's a matter of the geometry of the light cone.

> Perhaps some of the much more knowlegable will weigh in here,

Just because a lens is expensive doesn't mean that it will be a good astro
lens but you can pretty much bet that if it's cheap it WON'T be a good astro
lens. The exception to this are the 50mm lenses. They're not too expensive
anyway and some Nikon and Canon lenses 50mm lenses are considered good.
Check the archives; there's lots of lens talk in there. I know Nikons pretty
well; the 50mm f/1.4 is good; so is the older 105mm f/2.5. The 180mm f/2.8
is good but will cost  $250+ used. Vignetting plus spherical and chromatic
abberation are the key issues.
Bobby Middleton


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