File:NGC6888 (4144733943).jpg
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Summary
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| Description |
NGC6888 -- Crescent Nebula Subject: NGC6888 -- Crescent Nebula, and parts of IC1318 Image FOV = 3 degrees 15 min (195 min) by 2 degrees 10 min (1308 min) Image Scale = 7.5 arc-second/pixel Date: 2008/07/05 (H-alpha) and 2008/07/10 (RGB) Location: near Halcottsville, NY Exposure: H-alpha 14 x 10 minutes and RGB 12 x 10 minutes = 4h20m total exposure, ISO800, f/4.8 Filter: Baader 7nm H-alpha filter (RGB) and Astronomik UHC (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 frames, bias frames, and flat frames); Aligning and combing with Registar; Red channel = Max(UHC red, 100% H-alpha red ). Green channel = Max(UHC green, 33% H-alpha red). Blue channel = Max(UHC blue, 20% H-alpha red). Levels, curves, cropping/resizing, JPEG conversion with Photoshop CS. No sharpening or noise reduction. Remarks: H-alpha: temperature at end 57F, SQM-L reading 21.45 at start, 21.51 in middle; RGB: temperature at end 49F, SQM-L reading at start 20.54 (moon), 21.35 in middle (moon below horizon). A small part of IC1318 (part of Gamma Cygnii nebulosity) is visible at the lower left. |
| Date | |
| Source | NGC6888 |
| Author | s58y |
Licensing
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This image was originally posted to Flickr by s58y at https://flickr.com/photos/45032885@N04/4144733943. It was reviewed on 19 December 2021 by FlickreviewR 2 and was confirmed to be licensed under the terms of the cc-by-2.0. |
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| Date/Time | Thumbnail | Dimensions | User | Comment | |
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| current | 11:40, 19 December 2021 | | 1,560 × 1,040 (322 KB) | Siloepic (talk | contribs) | Transferred from Flickr via #flickr2commons |
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