Most notably, I was able to put into practice something called the "500 rule" which is a calculation that you can perform to figure out how long you can keep your shutter open before you start to capture "star trails" instead of stars. The formula goes as follows: 500/ (lens focal length) = max. shutter duration in seconds. I was using my Sigma 24mm f/1.8 lens on my Canon T2i. The Rebel line of Canon cameras has a 1.6x crop factor that needed to be included as well. So my calculation was a followed: 500/(24 times 1.6) = 13. So I had the max time my shutter could be open (13 seconds), I ended up dialing it back 1 second for safety. Since I was focusing to "infinity" the depth of field did not matter on the camera, so I was able to keep it wide open at f/1.8. These two known values allowed me to then dial in my ISO to something that would allow me a good exposure. I settled on 800. So for those of you interested, this sequence was shot RAW at f/1.8, ISO 800 and a shutter speed of 12 seconds. I set the intervalometer in my Magic Lantern hacked firmware to 16 seconds, allowing my camera 4 extra seconds to write the RAW file out of the buffer to the 32GB card. 1,464 images later (or 6.5 hours) and what you see below is what I can offer you.
I plan on going back to the RAW files and trying my hand at creating a star trail time lapse by gradually stacking the images. This is obviously something that will take a while, so I wanted to initially post this video for people who might be able to find a good use for it. The lights on the trees are actually from trains that pass through town. I was amazed that the images picked the light from them up.
You can preview and download the clips by clicking "read more" below. Happy Downloading!
As always, please e-mail, like us or share this on facebook, tweet, google plus, pinterest or do whatever you can to spread the word about this site. Thanks!
This video was shot using a Canon EOS Rebel T2i and a Sigma 24mm f/1.8 EX DG Lens