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

Date: March 2, 2010 11:52:08 AM MST

To: Astro_IIDC@yahoogroups.com

Subject: Re: Mars with 12.5" Cass

Hi Tim;

Nice Mars. Much better than anything I've done or will do (buried in ice fog again).

The direct URL is:

http://groups.yahoo.com/group/Astro_IIDC/files/Planetary/2010-03-01_06-31-18_U_TJP.jpg

HTH..

MIlton Aupperle

--- In Astro_IIDC@yahoogroups.com, "doobisary" <tjp314@...> wrote:

I just posted my best Mars with the 12.5" Cass that I took recently.  

I had been having trouble with the 12.5" Cass holding collimation, and couldn't figure out why until I heard a "clunk" when I picked up the OTA one day! Took the cell out and found that one of the edge supports was loose and had shifted, which let the mirror move about 3/8" laterally! Fortunately, I never point my OTAs to the ground, so it couldn't fall out! ...Got the problem corrected, and got the collimation very close to perfect. Seeing limited my ability to fine-tune the collimation, but I do think it is pretty good. All videos were shot at the f/23 Cass focus, so no additional glass in the train. Best results were with processing and enlarging by a factor of two in stacking.  

Jeff Beish says he thinks it's still out of collimation a bit, due to the ghosting off the brighter limb.  That may be, but I'm going to have to add an access door to the upper tube to allow adjustment of the 2ndary while the scope is on the mount.  As it is, it's a ladder job, and not fun in the dark!

-tim

Stats:

Note: 12.5" cass, flea2, seeing 6/10

trans 4/6 (edited to add: transparency was dropping and seeing rising during session, was probably still 6/10 seeing, but 3/6 trans when this image was taken).

=================== File:20100301_063118_U.mov #frames 4001

Color Camera - Model:'Flea2 FL2-08S2C' SerialNumber: 0x61AA7D

IIDC Format:7 Mode: 0 ClrCode: 10 MaxFps: 80.33 MaxPacketSize: 1856

Camera Display Format: 1032 x 776 16 bit

CCD Image Left: 364

CCD Image Top: 236

CCD Image Width: 304

CCD Image: Height 304

Gamma: 1.00

Blue Gain: 769

Red Gain: 522

Brightness: 424

Black Point: 0

Exposure: 16.67 ms

Sharpness Limiting On: 0

Dark Frame Subtraction On: 0

Flat Frame Correction On: 0

Invert Image On: 0

Flip Horizontal On: 1

Flip Vertical On: 1

Histogram Expand On: 0

Binning Off Color