M31 with a $60 lens
I recently got a chance to put in some "quality" time on M31 with an SMC Pentax-M 200mm f/4 lens operating at f/5.6. That lens in good condition sells for about $60 on ebay. (I bought mine used in a camera shop decades ago.) This image is the result. It does contain some residual chromatic aberration that more careful image processing could reduce but I don't think it detracts from the image too much. South is up in this view, which is my preferred orientation because the nature of the tilted disc of M31 is more obvious than when North is up. No flats, bias or dark frames but I dithered and used kappa-sigma clipping during stacking. Pentax K-3II on tripod only with tracking using Astrotracer (built in to camera). Total exposure was 87 minutes (260x20s @ ISO1600). Bortle ~3.5 sky with average transparency.
|Cheetah in the wild by cmgpereira|
|Kilchurn Castle, Scotland by johanmieke|
from Ancient Castles, Forts, and Defensive Structures - EXTERIOR
|Incoming by Scott Vail|
from Your Duck shot