Posts Made By: Jim Thommes

Here is an image of the cluster NGC 6604. It is surrounded by hydrogen in emission. A full size image is at:

http://jthommes.com/Astro/NGC6604.htm
Be sure to click on the image for full size)

Megrez II 80 mm at f/4.9
Artemis285 Ha RGB filters
G11/Gemini
Guiding - c8 at 1350 mm FL, DSI Pro, K3CCDTools

Also, just North is this field is the small emission nebula Sharpless - 54. An image of that is at:

http://jthommes.com/Astro/SH2-54.htm

Greetings All,
I have mostly poste on the CCD Deep Sky forum, but I have recently tried to do some work with a DSLR for astrophotography. I have enjoyed the process. My first target was simple - M3. I was using a Canon XT (350D) unmodified. I didn't have a bulb cable yet so I was limited to 30 second exposures. I used my C8 at about f/7.5 (Celestron 0.63 reducer at short distance). The somewhat slow optic and 30 second exposures did limit the signal somewhat - but I did get an image out of it. BTW, also my first experience using PHD guiding. The image can be seen at:

http://www.jthommes.com/Astro/DSLR/m3.htm
(Click on the image for a full resolution view)

Scope - C8 at f/7.5
Camera - Canon Rebel XT (350D)
G11/Gemini
Guiding - Megrez II at 1350 mm FL, DSI Pro, PHD Guiding

For a comparison, I have an image from 2005 with my Artemis285. The irony is that this image was also first light on the Artemis:

http://www.jthommes.com/Astro/m3.htm

I do plan on getting a cable for longer bulb exposure and likely will do the spectrum enhancement mod. Any tips on the mod would be greatly appreciated. Any tips on the processing are appreciated as well.

I am attaching a Low Rez image but full rez and exposure / processing details are on the links.

Greetings All,
I am continuing my explorations into DSLR imaging. I am still limited to 30 seconds with this image of M13. The framing is somewhat askew because I wanted to see if I could get NGC 6207 with 30 second exposure. I did - barely. I now have a bulb release cable so next images can be made at longer exposure times.

Full size image and exposure / processing details are at:

http://jthommes.com/Astro/DSLR/m13.htm
(be sure to click on the image for full resolution)

C8 at f/7.5
Canon 350D (no filters)
G11/Gemini
Guiding Megrez II at 1350 mm FL, DSI Pro, PHD Guiding

Here is an image of NGC 5033. It was made from several different data including a 2x2 bin on luminance. This lower resolution data had nice signal level and really didn't lose much over the 1x1 data. What was gained in signal level was useful to the image. Image looks like a soft focus, but I think it is the seeing. We seem to be struggling with seeing more often then it seems it has been in the past. A full size image and exposure / processing details are at:

http://jthommes.com/Astro/NGC5033.htm

C8 at f/6.2
Artemis285 LRGB filters
G11/Gemini
Guiding - Megrez II 80 mm at 1350 mm FL, DSI Pro, PHD Guiding.

An earlier image from 2005 is here:

http://jthommes.com/MiscAstro/Archives/NGC5033.htm

Hi Folks,
I am continuing my exploration of the DSLR world of Astrophotography. (I hope people aren't getting bored with my globs.) The link is to an M5 image. This is my first long exposure - bulb release image. I went for 120 seconds at ISO 400. I think going forward I won't go so low on ISO. Full size image and exposure / processing details are at:

http://jthommes.com/Astro/DSLR/m5.htm
(be sure to click on the image for full size)

C8 at f/7.5
Canon 350D - no filters
G11/Gemini
Guiding - Megrez II at 1350 mm FL, DSI Pro, PHD Guiding

I went for a for a deeper look M57 this time. In addition, I took some H-Alpha exposures binned 2x2 for greater signal. I did compress the dynamic range significantly to show the features, so some may find the image a bit unusual. A full size image and exposure / processing details are at:

http://jthommes.com/Astro/RingM57.htm
(be sure to click on the image for a full size view)

C8 at f/7.5
Artemis285 H-Alpha, IR Block, and RGB filters
G11/Gemini
Guiding - Megrez II at 1350 mm FL, DSI Pro, PHD Guiding

An earlier image is here:

http://jthommes.com/MiscAstro/Archives/RingM57.htm

Greetings All,

Here is another image with my DSLR (unmodified state). I have recently completed a successful ACF mod to my 350D, but this image was pre mod. (I suspect based on the subject, the mod would not have made much difference in this image.)

This is M7 with the Milky Way in background. A full size image and exposure / processing details are at:

http://jthommes.com/Astro/DSLR/m7.htm

Megrez II 80 mm at f/5.0
Canon 350D (unmodified) no filters
G11/Gemini
Guiding - C8 at 1350 mm, DSI Pro, PHD Guiding

I have been doing some DSLR work and I couldn't resist a cross post to this forum - sorry. I have been enjoying going back and fourth between DSLR and Art285 CCD Camera. They are both interesting tools in my imaging toolbag.

This is M7 with the Milky Way in background. A full size image and exposure / processing details are at:

http://jthommes.com/Astro/DSLR/m7.htm

Megrez II 80 mm at f/5.0
Canon 350D (unmodified) no filters
G11/Gemini
Guiding - C8 at 1350 mm, DSI Pro, PHD Guiding

What I was trying to image was the bright starcloud at the tip of the spout of the Sagittarius "Teapot". Typically I will frame a shot with test images placing the star pattern optimally on the CCD. This works well with the smaller field Art285. This image was with my DSLR and there were too many stars - I got lost. I tried to reset with an eyepiece (removing the camera).

Well, I reminded myself I was out having a good time, so I just stopped and imaged where I was pointing - I got close. This image shows the spout star, Alnsal, at the top edge. North is to the right. Two globular clusters - NGC 6522 and NGC 6528 appear as fuzzy stars in the upper center part of the image. There are some dark dust regions among all the stars.

I thought I would post the image the image and take (hopefully gentle) teasing about getting lost. Full size image and exposure / processing data is at:

http://jthommes.com/Astro/DSLR/SagittariusSF.htm

Megrez II APO at f/5.5
Canon 350D (no filters, ISO800)
G11/Gemini
Guiding - C8 at 1350 mm FL, DSI Pro, PHD Guiding

Here is an image of one of the 5 Messier Globulars in Ophiuchus - M14. I am a bit unsure of the colors. Seems that the Green and Blue exposures saturated at 36,000 ADU whereas Red was my more normal 56,000 ADU that I usually see with my Artemis285. (The Artemis285 does not top out at 65535 like you would expect of 16 bits) Not sure what the deal was on the Green and Blue. I scaled the Green and Blue up accordingly and produced what you see. (Though I notice many color images of M14 on the internet are very red - I assumed a color inaccuracy). Maybe it's me and the color is really very red.

Anyway, here is my version of M14:

http://jthommes.com/Astro/M14.htm

C8 (203 mm) at f/7.5
Artemis285 Camera - IR RGB filters
G11/Gemini
Guiding Megrez II at 1350 mm FL, DSI Pro, PHD Guiding

Here is an older image from 2004:

http://jthommes.com/MiscAstro/Archives/M14.htm