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A related, though much closer to home, experience I have had is an airplane flying through the field of view during a reasonably long exposure on a galaxy. The

A related, though much closer to home, experience I have had is an airplane flying through the field of view during a reasonably long exposure on a galaxy. The plane's transit left two long, continuous streaks through the image, one from each navigation light on the wing tips. The streaks had different brightness, likely due to the transmission of the filter I was using for red and green light. So in principle you could use knowledge of the filter transmission curve to work out which direction the airplane flew through the camera's field of view.

scrumper 9y ago
Well you don't need to do that, because the left wing has a red light, right has green. So as long as you're comfortable with the very reasonable assumption that the plane isn't upside down, you know which direction it was going. Edit: sorry, I didn't mean to say that you can't do what you suggested, more that if you were solely interested in direction you wouldn't need to. It'd still be an interesting exercise!
- privong 9y ago
  > Well you don't need to do that, because the left wing has a red light, right has green. So as long as you're comfortable with the very reasonable assumption that the plane isn't upside down, you know which direction it was going. The overwhelming majority of astronomical images (i.e., those not taken with a DSLR or other consumer-like camera) are monochrome images. So in any single exposure you don't retrieve a RGB color image. The color images you see from all professional and many amateur telescopes are reconstructed from multiple exposures through different filters (e.g., the one in the syfy.com article). So you would not see a red light and a green light – you just see two monochrome streaks with different brightness. Planes pass through a telescope field of view relatively quickly, so you most likely only see it in a single exposure.
  - scrumper 9y ago
    Ah, I misunderstood your original post - didn't realize you were photographing monochrome through a succession of filters. Thanks for the explanation.

scrumper 9y ago

Well you don't need to do that, because the left wing has a red light, right has green. So as long as you're comfortable with the very reasonable assumption that the plane isn't upside down, you know which direction it was going. Edit: sorry, I didn't mean to say that you can't do what you suggested, more that if you were solely interested in direction you wouldn't need to. It'd still be an interesting exercise!

privong 9y ago
> Well you don't need to do that, because the left wing has a red light, right has green. So as long as you're comfortable with the very reasonable assumption that the plane isn't upside down, you know which direction it was going. The overwhelming majority of astronomical images (i.e., those not taken with a DSLR or other consumer-like camera) are monochrome images. So in any single exposure you don't retrieve a RGB color image. The color images you see from all professional and many amateur telescopes are reconstructed from multiple exposures through different filters (e.g., the one in the syfy.com article). So you would not see a red light and a green light – you just see two monochrome streaks with different brightness. Planes pass through a telescope field of view relatively quickly, so you most likely only see it in a single exposure.
- scrumper 9y ago
  Ah, I misunderstood your original post - didn't realize you were photographing monochrome through a succession of filters. Thanks for the explanation.