ABSTRACT
Art is certainly in the eye of the beholder and although astrophotography is essentially record-taking, there is room for interpretation to turn multiple sub-exposures into photographic art. These include both technical and aesthetic attributes. Stars come in different colors from red through to blue, and a well exposed and processed image should retain star color. Bright stars always appear larger in an image and the exposures required to reveal faint nebulosity often render bright stars as a diffuse white blob. Photographers and artists often have an innate ability to compose images. The choices they make consider orientation, scale, framing, position of the center of interest, balance and directing or confining the view. Calibration, sorting and stacking are mechanistic in nature and are in effect an automated precursor to manipulation. Sorting removes the sub-standard exposures before image stacking and can be semi-automated based on a set of criteria or from a simple visual evaluation and rejection of poor exposures.
