Leo and Mars

Wide-field shot of the area around Leo. The bright dot low and right of center is Mars, and I think next to mars is the open cluster M44 (a.k.a. "the beehive cluster" or "Praesepe"). These pictures really need to be taken on nights without the moon. There's a huge gradient from dark to bright towards the direction of the moon.

I tried to add some lines and text for constellations, but it's fairly difficult because so many stars are showing in the picture:


A single 8 minute iso800 exposure of Cassiopeia through a Canon 17-40/4L lens at 17mm and F/5.6. The Andromeda galaxy (M31) is visible at the bottom center.

From the same night as my earlier Cygnus photo. This one is not as good with some light pollution or dew-problems at the left. The red artifact in the lower right corner is the same amplifier noise that's visible in the cygnus photo. My home-made lens hood causes vignetting.


A 32 minute exposure at iso200 through a Canon 17-40/4L (17mm @ F/5.6) of Cygnus and surrouding constellations with the milky way in the background.

There is a tree at the bottom right, and some local light-pollution bottom left, otherwise I am quite happy with this first serious go at a wide-field milky way picture. A dew-heater will allow longer uninterrupted sessions, and the fine focus could be improved slightly. Perhaps I should use a higher iso setting?

Update: after some discussion it seems that the red problems in the lower left corner may be due to amplifier-noise in the camera. Stacking a number of shorter exposures, for example 6x 10 min, is a better way of achieving a long total exposure with a DSLR. Cooled CCD cameras made for astrophotography are better for very long exposures - but also cost significantly more than consumer DSLRs.