On the cover of Popular Photography & Imaging Magazine, March 2003, is a spectacular photo by Dan Heller of a 3-1/2 hour exposure colorful night sky scene with circular star trails and lighted tents in the foreground.  Heller's advice:  "Moonless nights are darkest, allowing for longer exposures and brighter stars. An FL-D filter reduces the green-shift in really long exposures caused by reciprocity failure.  Moisture can cause mist on lenses during long exposures, so use a telescope heater or lens enclosure.  (March 2003, "TTL").

Tip #12 - Cable Release Splint:  Aside from the times your taking hand-held action shots or using a monopod or beanbag, a cable release is vital for ensuring crisp images at longer exposures.  A plunger style release may be a small and inexpensive item, yet it can cause a great deal of aggravation.  If you haven't lost it in the field, then sooner or later it develops an ominous bend at the junction where the metal collar meets the outer sleeve near the base.  Make a splint. Use a couple of wooden toothpicks to strengthen the release before it is bound up with colored waterproof tape. Outdoor Photography 101 Tips & Hints by Heather Angel (November 2002, "TTL")