Click image to enlarge
Made after collimation tests (see below)
shot on November 13, 2004 from my backyard in Castro Valley, Ca.
Compact Collapsible Cassegrain 18" @f/12.60 (F=5760mm)
IMG6303E camera @-35C
AO7 @ 16 Hz
RCOS Dichroic beam splitter
ST7E guide camera
FLI CFW1 Filter wheel
Optec Red filter
15 exposures of 5 minutes through Optec Red Filter (binned 2x2)
NO FLATS USED
--Collimation tests: Shot the same star inside and outside of focus at the center and each corner of the FOV
Need to investigate the asymmetry of left versus right. Suspicion is that a tilt of the imaging train relative to the optical axis is the cause. Needs further investigation.
Inside focus (click to enlarge)
Outside focus (click to enlarge)