From: "milton_aupperle" <milton@outcastsoft.com>

Date: March 15, 2011 11:53:07 PM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: Final Saturn reprocess


That looks really good Jim!!


Congratulations on getting a great image despite the atrocious weather this year.


As to your question, so far I'm very happy with the AT8RC.


No mirror flop at all, no changing focal lengths due to movable mirrors and a Carbon Fiber tube helps keep things in focus despite temperature changes. And it has a dual speed Crayford type focuser with zero image shift too.


It unpredictably cleared off tonight so I started by aligning the mount and focussing on Procyon. We are getting the same high frequency turbulence from last night, so I slewed over to the moon and still in focus. Then I slewed to M44 for a 45 minute guiding test and after that ran more guide test (using a Mag 9.3 guide star) on M67.


Here is my test 30 second exposure 9 frame stack of M67 after all of that, without refocussing.


http://groups.yahoo.com/group/Astro_IIDC/files/Other/M67_30sec_20110315_221832_L.jpg 


Field of View is 19 x 14' arc minutes  at 1625 mm FL with the 2/3" CCD.  All I did was a bit of levels to remove the moon glow amplified by the high altitude haze and stretch the image a bit. No sharpening at all.


The stars are round all the way to the edges. Even my guide stars in the OAG are are very round too, out to 45 arc minutes off axis. With the C8, the guide star was usually an elongated (2:1 ratio) blob.


I still have not run any collimation tests and this is all out of the box as it shipped from China.


TTYL..


Milton Aupperle


--- In Astro_IIDC@yahoogroups.com, "jimchung2338" <jim_chung@...> wrote:


I've been up for the past 20 hrs so going to bed, here's my final reprocess which is considerably smoother and more natural looking.



http://dl.dropbox.com/u/4852049/SaturnRGBMarch15.tif




Jim