Re: [ATM] Illuminated Field - How Much?

["Scott Ewart" <scott.e@quicksurfer.com>]

Jeff,
    Unless you're using high power with the bino-viewer, don't worry about
it.  You'll never see the effects from this slight light loss or added
diffraction.  That photo shows an extreme example.  If it's only 1 inch, you
won't see it at low power.
    Sure, it's not ideal.  But the alternative might be worse at low power.
Can you use it for higher power using some other optical layout like a
Barlow that wouldn't stick out (in)?  If not, then moving the mirror (or
shortening the tube) would not effect high-power viewing since you can't see
the part of the field that wouldn't be fully illuminated.

Scott


----- Original Message ----- 
From: "Jeff Morgan" <jeffmorgan@mindspring.com>
To: <atm@atmlist.net>
Sent: Tuesday, January 25, 2005 10:46 AM
Subject: Re: [ATM] Illuminated Field - How Much?


Currently using a 1.6" focuser. Actually, need to move the other
direction. The problem is the binoviewer is already too close in and
reaches too far into the tube. The focal plan needs to be pushed out
about 1". Page 91 of the March 05 issue of Sky and Telescope has a
photo illustrating the problem.


On Jan 24, 2005, at 10:11 PM, Don Clement wrote:

> An alternative to moving the mirror up the tube would be to use a low
> profile focuser and move the binoviewer closer in.
>
>
>
> Don Clement
>
> Running Springs, California
>
> http://www.ClementFocuser.com/
> atm

_______________________________________________
ATM mailing list http://www.atmlist.net/

_______________________________________________
ATM mailing list http://www.atmlist.net/