Re: C-11 + FR vignettes with wide field eyepiece

MitchAlsup_at_aol.com
Date: 02/04/05 

Date: 4 Feb 2005 08:53:50 -0800

The Celestron focal reducer is designed to shrink a 2" image circle
into (drum roll) a 1.25" image circle. {2.0*60% = 1.2}

A 40mm 65dFOV eyepiece uses around 45mm of the standard 50mm (2") image
circle. You should expect this EP to vignette with this focal reducer!
In general, focal reducers are for people who don't buy 2" eyepieces,
or people who do astro imaging with small sensors.

The C11 has a 2.7" (+/-) potential image circle, so a giant easy guider
will capture enough image circle that after being reduced by 60% will
still be about as big as the image circle accepted by the 40mm 65dFOV
EP.

Mitch