From: "Milton Aupperle" <milton@outcastsoft.com>
Date: August 25, 2008 1:17:58 PM MDT
To: Astro_IIDC@yahoogroups.com
Subject: New Grasshopper images
Hi Folks;
I'm out at my dark site for a few weeks vacation and have a couple
nights of reasonably good seeing so far. I've got a preliminary
version of the L R G B import and processing code up, which handles L
RGB two file, R G B three file and L R G B four file imports and
manual alignment, so I'm using it with the Monochrome Grasshopper
EXHAD camera for DSO's.
Here is my first L R G B with the grasshopper, 4 minute exposure and
my C8 at 1100 mm focal length. This was 2 days after full moon, so the
sky background was lit up pretty good.
http://groups.yahoo.com/group/Astro_IIDC/files/DSO/M57_20080818_LRGB_MJA.jpg
The alignment of the R G B Filtered images with the Luma image is not
good because I forgot to buy a plain glass filter for the Luma hole in
the Filter wheel. So I have to adjust the focus for Luma versus the R
G B Filters and that causes the image scale to shift by about 3
pixels. I'll have to add in scaling and rotation code to the LRGB
illumination methods
I also got a Luma only image of M101 too, which is shown below using a
4 frame summed stack of 15 minute exposures, effectively making this a
60 minute exposure.
http://groups.yahoo.com/group/Astro_IIDC/files/DSO/M101_20080824_15min_4Frame_MJA.jpg
M101 is tough target as by the time it's dark enough to image, it
drops down below 40° altitude, so one has to shoot quickly. I likely
will try imaging again to collect color filtered images using 2x2 binning.
I hope to image M82, M33, part of M31 and M110 if weather permits.
TTYL..
Milton Aupperle