File:IC1805 -- H-alpha + RGB.jpg
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Summary
| Description |
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 Location: near Halcottsville, NY Exposure: 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. |
| Date | 2007/11/10 H-alpha, 2007/11/13 RGB |
| Source |
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| Author | s58y |
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This image, originally posted to Flickr, was reviewed on 15 June 2012 by the administrator or reviewer File Upload Bot (Magnus Manske), who confirmed that it was available on Flickr under the stated license on that date. |
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| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 15:26, 15 June 2012 | | 1,400 × 960 (381 KB) | File Upload Bot (Magnus Manske) | Transferred from Flickr by User:Hike395 using flickr2commons |
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