Re: ATM Filter between eyepiece and eye?

["B. Pepin" <atmjedit@conceptsnet.com>]

Sure it works. At one time Zeiss sold a nifty five-color filter wheel
designed to slip on the outside of any of their eyepieces. Just remember
that eye-relief is a major factor, so the technique works best with longer
FL eyepieces. With most short-focal-length eyepieces you will be jamming
your cornea right down on the filter surface in order to get close enough to
the eye lens to see the whole image circle. For higher powers,
long-eye-relief designs such as lanthanum glass variants and the new
wide-fields such as the Tele Vue Radian and the Pentax XL series work best.

BP


----- Original Message -----
From: Frank Schiralli, Jr. <schiralli@mindspring.com>
To: Timothy Donovan <tjdonovan@worldnet.att.net>
Cc: <atm@shore.net>
Sent: Thursday, March 15, 2001 11:44 AM
Subject: Re: ATM Filter between eyepiece and eye?


>
> At 01:29 PM 3/15/01 -0500, you wrote:
> >
> >Hi all,
> Is it possible to use
> >a filter, (color or
> >light pollution etc) BETWEEN THE EYEPIECE AND THE EYE.
>
> Yes.  Some would even argue it is preferable to getting skin/eyelash oil
on
> the coatings of your EP's.  At least that's what Steve O'meara said at the
> WSP!!
>
> Frank Schiralli, Jr.
> Member, Astronomical Society of Long Island (ASLI)
> N 40* 54' 26.8"
> W 73* 19' 21.1"
> MPC 928
> Web Pg. http://members.tripod.com/~AstroImager/index.html
>