From: "Milton Aupperle" <milton@outcastsoft.com>

Date: February 2, 2008 7:03:12 PM MST

To: Astro_IIDC@yahoogroups.com

Subject: Mars Images over 1.25 hours.

Hi Folks;

I finally got around to posting my Mars Images I took over Christmas.

http://groups.yahoo.com/group/Astro_IIDC/files/Planetary/Mars_20071229_MJA.jpg

It was -25°C when I took the last sequence of Mars images, my optics

were starting to frost over again and Mars would be right over a fire

place heated cabin, so I packed it in. I wrapped the Carbon Fiber C8

tube with a cheap electric heating pad to keep the optics ice free

between imaging sessions. I only had to turn the blanket off for about

10 minutes before imaging and then the internal tube turbulence had

dissipated.

Seeing wasn't good enough to go beyond 5 meter focal lengths with the

C8 scope. I had enough light with the PGR Flea camera's big 7 micron

pixels to shoot at 20 to 33 ms exposure times and no gains, which

reduce image noise a lot. The higher frame rate help reduce turbulence

noise, but in the the movie you can see Mars move up to +/- 5 pixels

(+/- 1.5 arc seconds) between frames.

I used manual frame selection in Astro IIDC 4 to weed out some of the

softer frames in the stack, however there wasn't a huge difference

between automatic selection and manual in the resulting images.

Notable feature include Elsyium Mons, Hellas Basin, North Polar Cap

and Syrtis major.

TTYL..

Milton Aupperle