I learned star trails, light painting, and much more from Jon Fuller (Moab Photo Tours) and master photographer Tom Till. They co-lead workshops, one of which is a unique day-and-night photo week in Arches and Canyonlands during the darkest part of November. Great instructors and a great time: highly recommended! http://www.moabphototours.com/pages/workshops/arches-night.php. Later I made a fast Photoshop action to composite the trail segments from individual images... an article on this is pending.