When former Carter White House deputy counsel Michael Cardozo married Harolyn Landau, daughter of Washington real Estate morgul Nate Landau, in May, the father of the bride pulled out all stops. Guests at the reception and dinner of the Mayflower Hotel marveled at the array of food and lavish entertainment.

But one of the unique touches was a professional vidoetape film crew that recorded the wedding and such moments as the bride dancing with Vice President Walter Mondale, a guest at the reception. the filming and subsequent editing cost more than $5,000 and was done by a Pikesville, Md., firm called Omni Video.

The tab was unusually high because broadcast-quality Japanese cameras were used at the Cardozo-Landau affair--weddings have been videotaped by Omni for as little as $1,000. Morris Eventoff, Omni's president, says his staff has filmed, in addition to weddings, women giving birth, sky divers and Little League games.

Omni's strangest request has come from people who want to read their will on tape, so it can be played back after their death. Eventoff says people have taken the opportunity to single out particular family enemies, curse them, and tell them (almost) face-to-face why they're not being left a cent.