ABSTRACT
The familiar Orion constellation holds a number of secrets that reveal themselves with ever-increasing exposure. The Orion nebula is one of the most obvious constellations in the Northern Hemisphere and needs no electronic aid for location. It is a good choice for this assignment as it is easy to frame up in the viewfinder and its bright stars show up using the x10 focus magnifier feature on the LCD. The one drawback with imaging Orion is that it appears low in the sky and only momentarily rises above the imaging horizon. The exposure period is limited to the few hours as it passes between two neighboring houses. Imaging at a low altitude has other drawbacks, one of which is a strong sky gradient towards the horizon. With a tracking mount, the necessity to deliberately shorten exposures to prevent star trailing is removed and one is free to push for higher quality, by collecting more photons.
