Two of these titles won American Video Conference awards for excellence last year, and all three come from a leading producer of travel documentaries. Alaska, which topped the AVC travel category, is the most traditional and the least interesting of the three. It follows the familiar tourist-cruise route along the narrow strip of southeastern Alaska that borders British Columbia, with frequent pauses to sample bits of history, craftwork, native culture, scenery, etc. Though the photography is postcard-pretty and the commentary tour-guide informative, Alaska is a whirlwind tour through an area made to seem no more or less interesting than anyplace else on earth.

Exploring the Himalayas, AVC winner in the adventure category, is more ambitious and rewarding, taking viewers to one of the world’s most inaccessible places — the high mountains of Nepal and Kashmir. Operating on the principle that the area is best experienced as an explorer, Himalayas leaves the beaten tourist paths to poke around in the Buddhist temples of Ladakh and the jungles of Chitwan National Park (home of the endangered Bengal tiger and one-horned rhino) and to explore Sherpa villages at the foot of Everest.

Exploring Antarctica (not entered in the 1990 AVC competition) is the most fascinating of the three tapes, not least because its subject terrain is so forbidding. The ice-wrapped continent is so desolate and inaccessible that no human set foot there until 1821 or fully explored it until the early 20th century. This video (like the others, it is approximately 60 minutes long) brings keen insight into the conservationist challenge that humankind faces in protecting this pristine continental laboratory. Consequently, Antarctica has the strongest point of view of the three (always helpful) and the most to say (always welcome). B+