From: <maupperl@gmail.com>

Date: March 10, 2014 9:50:58 PM MDT

To: <Astro_IIDC@yahoogroups.com>

Subject: M42

Hi Folks;

After about 6 months of weather delays, I finally managed to capture a reasonably high resolution image of M42 on Feb 26, 2014 under no moon conditions. It's in the Files DSO Folder M42_Half_20140226_MJA.jpg. The new "neo" Yahoo web site crap has destroyed the ability to generate a direct URL, so you have to hunt for it yourself.

Seeing started off very good, but deteriorated considerably by the end and M42 only rises 30° above the horizon here. I shot it at 1650 mm with my AT8RC, and did a 4 panel shoot (four 60 second LRGB sequences each covering 1384x1036 pixels of Bottom Right, Bottom Left, Top Right and Top Left), processed in Astro IIDC and then merged together in a utility I wrote a decade ago. It takes about 23 minutes to shoot each panel (10 luma, 4 red, 4 green and 4 blue) and then about 5 minutes to select new guide star in the OAG, recalibrate and then start over. Basically I stayed outside at -13°C for about 2 hours to get it done.

I was running short of time (the western Condo wall was getting real close) and rushed the last panel (top left) set up, which left a Gap of about 50 pixels between two panels. I managed to reshoot it on March 3, but the moon was at half full by then - which raised the sky background by about 6,000 ADU. So getting the gap balanced out and levelled up with the other two panels was really tough.

The final stacked / joined image for printing will be 7100 x 5900 pixels (275 megabyte image in 16 bit RGB), which is good enough for about a 24" x 20" print at 288 dpi - ideal for Christmas gifts for next year.

TTYL..

Milton