Messier M42 NGC1976 Orion Nebula 31/10/2010 (Stacked and Processed - 3x60sec/ISO400) The second of a sequence of 3 stacks with 30, 60 (this) and 120 sec ISO-400 exposures to gauge the difference in this High Dynamic Range object. I revisted this in early 2012 to stack the 3 stacks using DSS HDR capability, so adding a fourth image to this comparison sequence. 3 images stacked using DeepSkyStacker 3.3.2 and cropped and colour adjusted by Adobe Photoshop CS5. Taken through the Apogee 80 on the SkyWatcher NEQ6 mount. Guided for 60sec @ISO 400 in-camera JPEG with no in-camera dark, no field flattener but with a light pollution filter. Things to note in this sequence of 4 images (this is the second) is the increased extent and density of the nebula as the the exposure time increased from 30 to 60 to 120 seconds. The central area becomes over exposed with the longer durations needing careful mid-tone stretching or HDR image amalgamation. The number of obvious hot pixels increases with exposure and without the use of 'dark frames' to try to combat these. This was my first experience with the high dynamic range of this object and the challenges of getting good processed image from the images. Cropping has avoided some of the spherical aberration from the outer edges of the original image. Focused using a Bahtinov Mask. Telescope - Apogee OrthoStar LOMO 80/480 without Field Flattener, Hutech LPS-P2 light polution filter, Canon 400D DSLR, Ambient xxC not noted. Mount - Skywatcher NEQ6 Pro. Guidescope - Orion ShortTube 80 with Star Shoot Auto Guider.

Messier M42 NGC1976 Orion Nebula 31/10/2010 (Stacked and Processed - 5x120sec/ISO400) The third of a sequence of 3 stacks with 30, 60 and 120 sec (this) ISO-400 exposures to gauge the difference in this High Dynamic Range object. I revisted this in early 2012 to stack the 3 stacks using DSS HDR capability, so adding a fourth image to this comparison sequence. 5 images stacked using DeepSkyStacker 3.3.2 and cropped and colour adjusted by Adobe Photoshop CS5. Taken through the Apogee 80 on the SkyWatcher NEQ6 mount. Guided for 120sec @ISO 400 in-camera JPEG with no in-camera dark, no field flattener but with a light pollution filter. Things to note in this sequence of 4 images (this is the third) is the increased extent and density of the nebula as the the exposure time increased from 30 to 60 to 120 seconds. The central area becomes over exposed with the longer durations needing careful mid-tone stretching or HDR image amalgamation. The number of obvious hot pixels increases with exposure and without the use of 'dark frames' to try to combat these. This was my first experience with the high dynamic range of this object and the challenges of getting good processed image from the images. Cropping has avoided some of the spherical aberration from the outer edges of the original image. Focused using a Bahtinov Mask. Telescope - Apogee OrthoStar LOMO 80/480 without Field Flattener, Hutech LPS-P2 light polution filter, Canon 400D DSLR, Ambient xxC not noted. Mount - Skywatcher NEQ6 Pro. Guidescope - Orion ShortTube 80 with Star Shoot Auto Guider.