Jupiter with Telephoto lens : 無料・フリー素材/写真
Jupiter with Telephoto lens / 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 | Jupiter - using telephoto lens and conventional exposure techniques (no video capture)Image Scale = 0.11 to 1.11 arc-second/pixel (see below)Date: 2011/11/05 Time = 9:32 PM to 9:36 PM EDT (according to camera) Estimated time = 2011/11/06 01:19 to 01:23 GMTExposure: 50 out of 64 x 1/400 sec at f/8, ISO 200 Lens: Nikon 800mm f/5.6 ED AI-S at f/8 (sharpest setting) Camera : unmodified Canon T2i = 550DMount: Astro-Physics AP900 -- rough polar alignment (no drift alignment)Processing: Focusing via EOS utility live view, exposures made from live view mode (EFSC active, so no mirror slap or first shutter curtain shake?). Raw conversion to TIFF using Canon Digital Photo Professional (batch). 64 individual shots manually cropped to 100 x 100 with Photoshop CS5 to cut down the size going into Registax. Alignment and stacking in Registax 5 with "50% drizzle". The best 50 out of the 64 frames in the stack were kept. The stacked output was saved as a single 200 x 200 TIF, and then "wavelets" processing was done with the guessed-at settings. Photoshop CS4 levels adjustment was done, then 5 alternative versions of the Registax output were made:A -- output from Registax -2x2 drizzle, so this gives a 200% crop at 0.55 arc-seconds/pixel.B -- "A" was downsized 0.5x, undoing the drizzle expansion, and giving a 100% crop at 1.11 arc-seconds/pixel. Image B shows how many pixels were illuminated on the sensor. Jupiter's disk was about 0.19mm across on the sensor, meaning that it covered about 0.03 square mm or about 0.01% of the DSLR sensor. C -- "A" was enlarged 1.5x, giving a 300% crop at 0.37 arc-seconds/pixel,to better show the Registax outputD -- The pixels in "A" were enlarged 5x (Photoshop "nearest neighbor" method), to better show what the registax output looks like. E -- The pixels in "B" were enlarged 10x (Photoshop "nearest neighbor" method), to better show what the pixels in the 550D sensor saw during the subexposures. Finally, text was added and these were combined into one composite image with Photoshop, which was converted to JPEG (quality=12). Obviously, the results here are far below average, and there's a long road ahead before I can take acceptable planetary images. |
| 撮影日 | 2011-11-05 21:33:00 |
| 撮影者 | s58y |
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