Some Time Under The Stars

I find that time spent under the stars, even when the skies are not very good, as they are not around Starlight Observatory any more, is time for me to recuperate, especially since the diagnosis. Last night I was able to take the Canon DSLR out for an hour to try something different for me: nightscape imagery. Basically, this amounts to pointing the camera at the sky, and taking as long of an exposure as you think you can get away with and not have star trails; ie, the stars remain round looking, not as streaks. I had been wanting to take a time lapse image of the sky to show the grandkids how the sky moves, so last night, I did. Basically, the time lapse is just multiple nightscape images.

The start time was about 9PM EDT, with obvious clouds. The sun set almost an hour before I started, but you can see the sky still getting darker as we come to the end of astronomical twilight. You can also see a change in color, as the light dome from the college town to my south (we are looking south, towards the town) emerges and grows prominent. This was fun, and I might try it from other locations, should I be able to travel again. It wasn't hard to do. The area of the sky is around Canis Major (the big dog) and Orion, to the right (west). Best seen full screen.

The second thing I wanted to try was ultra short imaging, by which I mean lots of short exposures to see how that might stack up against fewer longer exposures. Below is a stack of 50, 5 second exposures, same area of the sky, with only dark subtraction applied for calibration frames. Each of the frames in the video are 20 seconds each, while each frame used for the image below is only seconds each. I think I can see more stars in the stacked 5 second image than the 20 second image. I could also work on the 5 second image a little to decrease the effect of the light dome. Over all, though, I'm pretty impressed.

50, 5 second images stacked. Sorry about the large file size.