Screen Gems

Video art has been around for 40 years, since the invention of the portable camera, but it never got (and sometimes didn't deserve) very much respect. But that's changing. Technological advances have made editing easier and large-scale gallery projection possible, and artists have stepped forward with work of indisputable power. In fact, film and video art feature in every submission short-listed for this year's Turner Prize, the British art world's most prestigious award, presented last week (the works are on exhibit at Tate Britain in London until Dec. 23). And a show at Tate Modern on London's South Bank, "Time Zones:...