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Gibbous Moon with Telephoto Lens | by s58y
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Gibbous Moon with Telephoto Lens

Gibbous Moon - 100% crop from 31 stacked subexposures


Image Scale = 1.11 arc-second/pixel


Date: 2011/11/04 - 6:52 PM to 6:55 PM


Exposure: 31 out of 57 x 1/640 sec at approximately f/8, ISO 100

Lens: Nikon 800mm f/5.6 ED AI-S at about f/8 (seemed sharper than f/5.6 or f/11)

Camera : unmodified Canon T2i = 550D


Mount: 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?). 57 individual shots cropped to 1800 x 1500 with Photoshop CS5 to do rough alignment (Registax does not like exposures unless they are approximately aligned first). Alignment and stacking in Registax 6 with "50% drizzle". There were purplish patches in the image, so I did not use the color option in Registax. The intention was to keep the best 45 out of the 57 frames in the stack, but Registax stopped, and I had to use task manager to end it. I tried again asking to keep 30 frames, and ended up with 31 out of 57 frames. The stacked output was saved as a single 3600 x 3000 TIF, and then "wavelets" processing was done with the various guessed-at settings. The best one I tried seemed to be with linear steps and "layer" settings of 75,25,6,2,1,1. Photoshop CS5 image rotation and levels adjustment was done. Then the image was downsized back to 1800 x 1500 to get back to 100% crop and finally JPEG conversion (quality = 11) was done.

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Taken on November 4, 2011