I shot 45 images of Comet 21P to make a time lapse, but I thought it would also be interesting to make a composite of the first frame and a frame taken exactly one hour later. The idea being that with a bit of pixel measurement and mathematics, the comet's speed could be calculated. It works out that Comet 21P was travelling at about 22 km/s across our field of view - impressive!
Telescope:
Camera:
Exposures:
Thomas Cooke 10" refractor
Canon EOS 1Dx
2 x 16s at ISO 6400