M81LRGB(500).jpg (31792 bytes)

Higher-resolution versions:  1280 x 1024  1680 x 1050  2004 x 1336

Object Type:
 Spiral Galaxy (SA(s)ab)
Constellation: Ursa Major
Magnitude: 7.9
Size: 27' x 14'

Equipment: Meade 14" LX200R/STL-11000M/Astrodon LRGB filters/Paramount ME
F-ratio: f/9.5
Exposures: LRGB:  L 10 x 6 minutes, binned 2x2: R 10 x 6 minutes: G 10 x 6 minutes: B 10 x 6 minutes: RGB binned 3x3
Date: March 29, 2008
Landers, California, USA
Technical Notes:
Individual expsoures were dithered using
CCDAutoPilot2 and then sigma combined. Contrast adjustments were made in Photoshop CS with Levels and Curves. The RGB images were combined in Registar 1.0. The luminance image was sharpened with a High Pass Filter using a Radius of 4 pixels, and selectively applied using a Layer Mask. A Gaussian Blur of 1 pixel was applied to the dim portions of the RGB image. The RGB image was duplicated and the resulting layer combined using Soft Light to enhance color.

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