My serious interest in photography started with astrophotography almost twenty-five years ago, in a pre-digital era, with an Olympus OM-1 camera and an 8″ Schmidt-Cassegrain telescope. My wife and I, together with a bunch of friends and fellow graduate students, would bring the telescope to the top of a mountain above our campus and spend cold nights taking turns looking at faint smudges in the eyepiece. The astrophotography was exceedingly difficult, but the observational astronomy was fun in its own right, and it also lead me to terrestrial photography, first as a hobby, and later professionally.
Now I am getting back to astrophotography and discovering that it is an entirely new world, comparing to when I left it. Not that the objects in the sky changed much, but my ability to observe and photograph them has been brought to a different level by the developments in technology.
For my first comeback attempt, I selected M81, a.k.a. Bode’s Galaxy (on the left in the photo above). It’s a neat galaxy to photograph because of its brightness (apparent magnitude of 6.9) and the fact that it has a neighbouring galaxy – M82 (The Cigar Galaxy, on the right in the photo above) that fits nicely in the same field of view of a telescope (mine is an 81 mm refractor with a focal length of 478 mm, coupled with a full frame mirrorless camera). So you get to see two galaxies, one face-on and one from the edge, for the price of one.
I made the image above by stacking forty-two 25-sec exposures taken at ISO 800. The telescope was on an equatorial mount, which provided tracking. No guiding was used in this shoot (hence the relatively short exposures). I actually shot more images on the previous night, when the wether was better, but I messed up the flat calibration frames (note to self: make sure the exposure is longer than 2 sec when shooting flats using a light panel to avoid banding). The photos below are closer crops on M81 and M82.
Bode’s Galaxy is 96 light-years in diameter (about half the size of our Milky Way), and it contains more than 250 billion stars. Its light travelled for about 11.8 million years before I caught it in front of my house.
