20-12-2010. Measurement of EQ3-2 PE. Skywatcher MC 127 + 2*barlow into Canon EOS 450D (0.38 arcsec per pixel). Image taken every 6sec for approx 15minutes. Pixel positions measured manually (too cold for a laptop and webcam outside) for each of 160+ images and graphed in Excel. Note - the x axis should read worm angle (degrees), not Time(s).