Messier 51, the Whirlpool Galaxy, the classic face-on spiral galaxy in Canes Venatici in the northern spring sky. This is a stack of 6 x 10-minute exposures with the Astro-Physics 130mm apochromatic refractor at f/6 (with the 6x7 Field Flattener) and with the Canon EOS Ra camera at ISO 800. As an experiment on this mild but still cool spring night I did not shoot dark frames or LENR in-camera darks to see the extent of thermal noise. There was quite a bit at the single pixel level, proving that the camera does need darks or LENR when the ambient temperature is warmer than a sub-zero winter night.
A telephoto lens image of the spiral galaxy Messier 51 in Canes Venatici below the handle of the Big Dipper. This is shot to simulate the field of view of binoculars for illustration purposes. The star at top left is Alkaid in Ursa Major. This is a stack of 8 x 1-minute exposures with the 200mm lens at f/2.8 and Canon 6D MkII at ISO 800, tracked but unguided on the Mach 1 mount, on April 28, 2019.
M52 and Bubble Nebula area with 5-inch AP apo at f/4.5 with telecompressor/field flattener and Canon 20Da camera. Stack of four 8-minute exposures. Taken from home Nov. 20, 2006 under very good conditions.
