Posts Made By: Jim Thommes

I have had two set ups for a little while now. One primary imaging set up and one wide field DSLR set up. I get a set of frames started on the main set up, then when that is going, I set up the DSLR. This session in March was the first time I shot the same subject with both set ups. The first image is NGC 3628. The downside is that I had a bout a 30F degree change from focus to final frame - it's amazing the impact that can have on focus. Image as well as exposure and processing details are at:

http://www.jthommes.com/Astro/NGC3628.htm

Scope: C8 at f/8
Camera: Artemis285, Astronomik LRGB filters
Mount: G11/Gemini
Guiding: Megrez 80 mm at 555 mm FL, DSI Pro, PhD guiding

The second image is a wide field of NGC 3628 which is of course more popularly known as the Leo Trio galaxy group. Image and exposure / processing details are at:

http://www.jthommes.com/Astro/DSLR/LeoTrioWF.htm

Scope: Zenithstar 66 mm APO at f/4.8
Camera: Canon 350D (Baader ACF modified)
Mount: Celestron CG5 Advanced Series
Guiding: Home made 180 mm FL guide scope, DSI Pro, PhD guiding

Here is M101 made with my new ST8300M. I've been out a couple of times with it but I still need to get my focusing together with CCDSoft. Image and exposure / processing details are here:

http://www.jthommes.com/Astro/M101D.htm
(be sure to click on the image for full res)

Scope: C8 at f/7.5
Camera: ST8300M - Astronomik LRGB 1-1/4 " filters (yes, 1-1/4" - vignetting not too bad)
Mount G11/Gemini
Guiding: Megrez II 80 mm at 555 mm FL, DI Pro, PhD Guiding

Oh, and I did add some 2009 Ha data from my Artemis285 camera.

Jim

Hi All,
I recently took some data for an image of M95 and M96 with my Trusty Artemis285. Image and exposure details are at:

http://www.jthommes.com/Astro/M95-96.htm
(click on the image for full resolution)

Scope: WO Zenithstar 66 APO
Camera: Artemis285 Edmund Optics RGB filters. (My Astronomik LRGBs are now on the ST8300)
Mount: CG5 with GOTO Controls (Celestron)
Guiding: Home made guide scope 180 mm FL, DSI Pro, PhD Guiding

Last year I took a wide field image of M95 and M96 with my Canon 350D. That image is here:

http://www.jthommes.com/Astro/DSLR/M95_96_105.htm

Thanks for looking.
Jim Thommes

This is NGC 4517 along with its' partner (NGC 4517A?). This was the ST8300 on the C8. I am still using 1-1/4 inch filters, so overall with the C8 and all, this setup is not my optimum. I do like the 8300 chip since I can bin 2x2 for more reasonable image scale on 1600 mm and still have a reasonably nice size image. Image and details are at:

http://www.jthommes.com/Astro/NGC4517.htm

Scope: C8
Camera: ST8300 Astronomik LRGB
Mount: G11/Gemini
Guiding: Megrez 80 mm at 555 mm FL, DSI Pro, PhD Guiding

Jim Thommes

Hi All,
I have this image of a field of galaxies in Virgo (actually part of the Virgo Cluster). I used my newly acquired David Levy Maksutov Newtonian from Explore Scientific - first light. It does a good job with large sensors. This image was with my Canon 350D which has a 22 mm horizontal dimension. The scope has a 152 mm objective and a pretty large secondary mirror to accommodate large sensors. I am pretty pleased with its image capability and I think it will do well with the ST8300's slightly smaller pixels.

Here is the image, exposure and processing details are also on this page:

http://www.jthommes.com/Astro/DSLR/NGC4281Group.htm


Scope: Maksutov Newtonian 152 mm f/4.8
Camera: Canon 350D ISO800
Mount: G11/Gemini
Guiding: Megrez II 80 mm at 555 mm FL, DSI Pro, PhD Guiding

Jim Thommes
http://jthommes.com/

Here is NGC 5139 taken from the San Diego area. The challenge shooting this is due of course to this object being so near the horizon (9 degrees at max elevation). The good news is that the overall seeing was pretty good so the seeing next to the horizon wasn't so bad. The challenge is the color. I did apply Atmospheric Extinction factors to the red and blue color channels (green normalized to 1.00). That way I avoided this object coming out totally red. The image is cropped a little - I am still using 1-1/4 inch filters on an ST8300M.

Image as well as exposure and processing details are here:

http://www.jthommes.com/Astro/Omega%20Centauri.htm
(be sure to click on the image for a large resolution version)

some details.....

Scope: ES Mak-Newt 152 mm at f/4.8 (731 mm FL)
Camera: ST8300M - Astronomik LRGB filters
Mount: G11/Gemini
Guiding: Megrez 80 mm at 555 mm FL, DSI Pro, PhD Guiding

Here is an M8 pic I did recently. This is a high dynamic range object, so I worked the processing to preserve the core while bringing out the lower signal level of the wider reaches of the nebula. The ST8300M and Mak-Newt 152 mm scope continue to be effective for me. Image and exposure / processing notes are at:

http://www.jthommes.com/Astro/Lagoon.htm

You can follow the indicated links for full resolution and H-Alpha only images

Scope: Explore Scientific 152 mm Mak-Newt
Camera: ST8300M (Astronomik HaRGB filters) (yes, I am still using 1-1/4" filters)
Mount: G11/Gemini
Guiding: Megrez 80 mm refractor at 555 mm FL, DSI Pro, PhD Guiding

All,
Richard Crisp had offered some advice on my recent posting of the Lagoon Nebula. I reprocessed accordingly (at least in principle). I used the RGB data stretched up to the H-Alpha levels as a color layer. I also combined the Ha data blended with blue under the color layer to help tighten up the stars on the RGB. I was a quick reprocess and there may be some artifacts, but a couple of things happend:

1. The little blue reflection nebula in the upper left now shows up. It was completely invisible in the earlier post.

2. The colors are quite a bit different - possibly a bit more muted but more natural?

The reprocessed image is here:

http://www.jthommes.com/images/M8_MN152_PS2RevA.jpg

For reference, the original image is here:

http://www.jthommes.com/Astro/images/M8_MN152_PS2_large.jpg

I think I like the reprocess color better. What do you think?

Here is the M10 globular cluster. I'm still practicing a bit with the new ST8300M. This is a somewhat wide field for a globular. I am using a 731 mm FL scope for this image (152 mm Mak-Newt. Image and details can be seen here:

http://www.jthommes.com/Astro/M10.htm
(click on the image for full FOV and resolution)

Scope: Levy Mak-Newt 152 mm
Camera: ST8300M (Astronomik LRGB filters)
Mount: G11/Gemini
Guiding: Megrez 80 mm at 555 mm FL, DSI Pro, PhD Guiding

IC 4665 is not an exciting open cluster, but it is an interesting one. It is a 4.2 visual Mag cluster spanning 70 arc minutes of sky. Yet it not only does not make Messier's catalog, but it does not make Herschel's / Dreyer's NGC. One reason (speculation) given is that it is a large, coarse cluster and not recognized as an object by the early astronomers.

I took a quick shot of it awhile back. Image and exposure / processing details are here:

http://www.jthommes.com/Astro/IC4665.htm

Scope: Zenithstar 66 mm APO
Camera: Artemis285 (Edmund Optics RGB's)
Mount : CG5 GOTO (Celestron ASGT)
Guiding: Homemade 180 mm FL guide scope, DSI pro, PhD Guiding