M51 The Whirlpool Galaxy

These pictures are in reverse chronological order but that doesn't mean the best one is at the top.

My fourth attempt at M51. Here I used my ST80 refractor and my new Atik 16ic colour camera. The shoter focal length means I have a wider field of view showing M51 against the foreground and background stars. This was one of the first times I had used this camera and I was having difficulties with the focussing. This picture is in fact slightly out of focus and I have tried to hide this by over-enhancing it. So it is not a good picture and I hope that one day I can replace it with a better one.

Date and Time: 9th February 2008 00:53 to 01:30 UT
Camera: Atik 16ic colour
Telescope: Skywatcher ST80 refractor
Capture: Artemis Capture. 180", 13 frames.
Processing: K3CCDTools. 12 frames stacked. Histogram stretched 16-80, unsharp mask 5 pixels factor 100
PhotoImpact. Gamma 1.2, unsharp mask 5 pixels factor 100, brightness -5.

My third attempt at M51, this time using the LRGB technique. Four AVI files were collected, one (L) through a simple IR-block filter, and three (R, G, B) through red, green, and blue Astronomix filters, and using my monochrome, raw-modified Atik ATK 1-HS camera. Conditions were particularly good; the night was clear and steady and M51 was almost overhead. There is not a lot of colour in the image, but you can compare with the L image used to create it by moving your mouse over the picture.

Date and Time: 18th April 2007 23:19 to 24:22 UT
Camera: Atik 1-HS with Astronomix filters
Telescope: LX200 with 0.33 focal reducer
Capture: K3CCDTools. High gamma, 25", 57% gain, 50 frames (L), or 85% gain 25 frames (RGB), plus 10% dark frames
Processing: K3CCDTools. All frames stacked. L image, histogram stretched 25-180, unsharp mask 3 pixels factor 200
Registax. Gamma 1.3, brightness -10.

My second attempt at M51. The picture was made by taking 45 frames and 5 dark frames and stacking them in K3CCDTools. I then stretched the histogram to various extents (between 0-80 and 0-160), saved these images before recombining them. This image was then imported into Registax where the gamma curve was adjusted to a sigmoid shape to produce better contrast in the spiral arms without brightening the background too much or saturating the brighter parts. Finally some tweaking of the brightness and contrast and a passage through NeatImage, to reduce the noise, produced this final image.
Date and Time: 25th April 2006 23:00 UT
Camera: ToUcam 840K SC1
Telescope: LX200 with 0.33 focal reducer
Capture: K3CCDTools. High gamma, B/W, 60", 57% gain, 45 frames and 5 dark frames
Processing: K3CCDTools. 44 frames stacked. Histogram stretch (see above).
Registax. Gamma (see diagram), brightness -30, contrast 110.

My first attempt at M51. The picture was made by taking 70 frames and 7 dark frames and stacking 59 of them in K3CCDTools. I then stretched the histogram 0-100, and finally adjusting the contrast, brightness, and gamma in PhotoImpact.
Date and Time: 4th April 2004 21:13 UT
Camera: ToUcam 840K SC1
Telescope: LX200 with 0.33 focal reducer
Capture: K3CCDTools. High gamma, B/W, 30", 95% gain, 70 frames and 7 dark frames
Processing: K3CCDTools. 59 frames stacked. Histogram 0-100.
PhotoImpact. Brightness -25, contrast 20, gamma 1.3.

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	My fourth attempt at M51. Here I used my ST80 refractor and my new Atik 16ic colour camera. The shoter focal length means I have a wider field of view showing M51 against the foreground and background stars. This was one of the first times I had used this camera and I was having difficulties with the focussing. This picture is in fact slightly out of focus and I have tried to hide this by over-enhancing it. So it is not a good picture and I hope that one day I can replace it with a better one. Date and Time: 9th February 2008 00:53 to 01:30 UT Camera: Atik 16ic colour Telescope: Skywatcher ST80 refractor Capture: Artemis Capture. 180", 13 frames. Processing: K3CCDTools. 12 frames stacked. Histogram stretched 16-80, unsharp mask 5 pixels factor 100 PhotoImpact. Gamma 1.2, unsharp mask 5 pixels factor 100, brightness -5.
	My third attempt at M51, this time using the LRGB technique. Four AVI files were collected, one (L) through a simple IR-block filter, and three (R, G, B) through red, green, and blue Astronomix filters, and using my monochrome, raw-modified Atik ATK 1-HS camera. Conditions were particularly good; the night was clear and steady and M51 was almost overhead. There is not a lot of colour in the image, but you can compare with the L image used to create it by moving your mouse over the picture. Date and Time: 18th April 2007 23:19 to 24:22 UT Camera: Atik 1-HS with Astronomix filters Telescope: LX200 with 0.33 focal reducer Capture: K3CCDTools. High gamma, 25", 57% gain, 50 frames (L), or 85% gain 25 frames (RGB), plus 10% dark frames Processing: K3CCDTools. All frames stacked. L image, histogram stretched 25-180, unsharp mask 3 pixels factor 200 Registax. Gamma 1.3, brightness -10.
	My second attempt at M51. The picture was made by taking 45 frames and 5 dark frames and stacking them in K3CCDTools. I then stretched the histogram to various extents (between 0-80 and 0-160), saved these images before recombining them. This image was then imported into Registax where the gamma curve was adjusted to a sigmoid shape to produce better contrast in the spiral arms without brightening the background too much or saturating the brighter parts. Finally some tweaking of the brightness and contrast and a passage through NeatImage, to reduce the noise, produced this final image. Date and Time: 25th April 2006 23:00 UT Camera: ToUcam 840K SC1 Telescope: LX200 with 0.33 focal reducer Capture: K3CCDTools. High gamma, B/W, 60", 57% gain, 45 frames and 5 dark frames Processing: K3CCDTools. 44 frames stacked. Histogram stretch (see above). Registax. Gamma (see diagram), brightness -30, contrast 110.
	My first attempt at M51. The picture was made by taking 70 frames and 7 dark frames and stacking 59 of them in K3CCDTools. I then stretched the histogram 0-100, and finally adjusting the contrast, brightness, and gamma in PhotoImpact. Date and Time: 4th April 2004 21:13 UT Camera: ToUcam 840K SC1 Telescope: LX200 with 0.33 focal reducer Capture: K3CCDTools. High gamma, B/W, 30", 95% gain, 70 frames and 7 dark frames Processing: K3CCDTools. 59 frames stacked. Histogram 0-100. PhotoImpact. Brightness -25, contrast 20, gamma 1.3.