Re: ATM 75mm 3" or 100mm 4" eyepieces

[epabcc@epa.ericsson.se (Bratislav Curcic)]

> Besides, the off axis coma even at f8.f would be bad

Andy, 

off axis coma isn't function of eyepiece's focal length, it depends
only on eyepiece's apparent field of view. That is, if you can't see
coma in an 5mm eyepiece with 60 degrees field of view, you won't see it
in ANY 60 deg AFOV eyepiece, 75mm or longer, doesn't matter.
Coma is a LINEAR function of off-axis distance.
Besides, there are only few eyepiece designs that suppress its own
astigmatism well enough to show Newtonian's coma (Nagler and copycats,
and few more obscure designs).

Bratislav