One of the most basic types of astrophotography and yet equally stunning is that involving star trails, particularly around the celestial poles or immediately due east or west. In addition to capturing the motion of stars around the north pole which are circumpolar and, hence, never rise or set, we also have the ability to capture seasonal constellations and stars in such photos, thus allowing for different opportunities during different seasons. Star trail photos also provide direct evidence that our planet rotates and does so at a rate of 15° per hour. Furthermore, by studying the arc for a particular star, especially as far away from the pole as possible, one can indirectly estimate the length of the exposure which, for the examples below, range from seven to eight hours in duration and are totally dependent on the onset and end of astronomical twilight during each session.

Many of the photos below are centered on Polaris, a double star system which represents our quickest means to locating the north celestial pole, for it lies less than 1.0° from it, and is an excellent starting point for the polar alignment of a telescope (and finding your way home if you are lost!). Due to the extended length of the typical exposures involved, the best film for such work is Kodak Elite Chrome (ISO 100) whose reciprocity failure is nearly zero or Fujichrome Velvia and Provia (ISO 50 and 100) emulsions with equally impressive curves! With respect to equipment, it is rudimentary, for a camera with extended exposure capability is required along with a firm tripod and shutter release and locking cable. It is also preferable that the camera used have a mechanical shutter so that battery consumption and power does not become an issue during mid-exposure. The final requirement is a location with dark skies - the darker the better so that the trails and their colouration will be as bright and contrasty as possible - with, preferably, an interesting foreground which can be used to enrich the final result.

Each of the multi-hour exposure sequences below was based on the end of astronomical twilight and its onset the following morning, for the sky is darkest during this period (see here). Similarly, the lunation in each particular month was studied so as to identify days where the the moon would neither rise nor set during the end and onset of astronomical twilight and which, in general, translates to about seven or eight days of opportunity each lunation (the latter part of one lunation and the initial part of the consequent lunation).