From: "Jerry B. Hillman" 
To: 
Reply-To: "Jerry B. Hillman" 


Hi all,
I need some help understanding what some of these numbers mean. With parabola checked
R,mm  3810.461
b -1.000
Strehl .999
RMS 1.0
o(RMS) .2


With conic checked
R,mm 3810.454
b -1.003
Strehl 1.0
RMS 0.6
o(RMS) .1

The star test tonight showed slight astigmatism at high power that went
away when I rotated the mirror about 30ø.  Ater I did that, the outside of
focus and inside of focus were identical as nearly as I could tell. Neither
were perfectly round but very nearly so. Both had a slightly brighter ring
surrounding more rings with a dark center. In focus was a small disk
surrounded by slightly irregular halos. I didn't get to Ronchi test it
because high clouds rolled in.  My diagonal is too small. I see some
viginetting (sp) of the image when I am out of focus. I didn't get to see
Jupiter. It is behind the trees by the time it gets dark enough to see. 
Saturday I am going to get up early and take a look at Mars.

I have the six test file saved for anyone that might want to check my
entries. I think this mirror is done.  I just need to fine tune the scope
and the mirror cell, and buy a bigger diagonal to continue testing. Clear
skies, jerry

--- BBBS/NT v4.01 Flag-4