IC1805 -- H-alpha + RGB : 無料・フリー素材/写真
IC1805 -- H-alpha + RGB / s58y
| ライセンス | クリエイティブ・コモンズ 表示 2.1 |
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| 説明 | Subject: IC1805 -- Heart Nebula (RGB + H-alpha) Image FOV = 2 degrees 55 minutes by 2 degrees (175 minutes by 120 minutes) Image Scale = 7.5 arc-second/pixel Date: 2007/11/10 H-alpha, 2007/11/13 RGB Location: near Halcottsville, NYExposure: 26 x 10 minutes H-alpha plus 13 x 10 minutes RGB = 6h30m total exposure, ISO800, f/4.8 Filter: Baader 7nm H-alpha filter (H-alpha), IDAS LP filter (RGB) Camera: Hutech-modified Canon 30D Telescope: SV80S 80mm f/6 + TV TRF-2008 0.8X reducer/flattener = 384mm FL, f/4.8 Mount: Astro-Physics AP900 Guiding: ST-402 autoguider and SV66 guidescope. MaximDL autoguiding software using 6-second guide exposures Processing: Raw conversion and calibration with ImagesPlus (dark and bias frames only, no flat frames); Aligning and combing with Registar; Levels adjustment on RGB and H-alpha image. Then:Red channel = 1/3 * RGB_ red + 2/3 * max(gamma(RGB_red, .75), Ha_red)Green channel = 1/3 * RGB_ green + 2/3 * max(gamma(RGB_green, .75), 1/3 * Ha_red/5)Blue channel = 1/3 * RGB_ blue + 2/3 * max(gamma(RGB_blue, .75), 1/3 * Ha_red/5)Then, more levels, cropping/resizing, JPEG conversion with Photoshop CS. Remarks: Temperature at end: 22F (H-alpha), 26F (RGB); SQM readings: 21.3 to 21.49; No noise reduction. |
| 撮影日 | 2009-07-31 00:16:51 |
| 撮影者 | s58y |
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