THE relationship between film and video has been a changeable and sometimes unfriendly one. Film loyalists have regarded video as an upstart, easy to abuse (videotape is cheap and recyclable, so less care may be taken when deciding what to put on it) and inferior in visual quality. In turn, video freaks have disdained film's lack of flexibility, and its connection with the outmoded past rather than the exciting future of visual art.In the past, I have usually sided with the film contingent. Film does look better than video in most cases, and movies rerecorded on video cassettes invariably suffer from the translation. Many a first-rate film artist, moreover, has done less interesting work after being seduced by the relative ease and cheapness of video production. I have often called video a medium for tinkerers - great for experimentation and fooling around with new effects, but not so great for serious image-making, except in the case of a few exceptional artists such as Bill Viola and Nam June Paik. The times are changing where this rivalry is concerned, however. For the past dozen years, the Whitney Museum of American Art has included noncommercial film and video in its internationally watched Biennial exhibitions, and its latest batch of film and video selections - works made by 30 artists with widely varying interests and talents - is finally convincing proof that video has come into its own as a major artistic medium. Just as important, it indicates that artists in both the film and video fields are increasingly relaxed about the differences between the two technologies, and are happy to move from one to the other, and even to combine them within a single work. This seems a healthy development, pointing toward a future in which film and video are seen to offer different but equally valid possibilities - operating side by side like oil and watercolor, orchestra and chamber ensemble, modern dance and classical ballet. A fine example of video's new maturity is Steve Fagin's latest offering, "The Machine That Killed Bad People," a two-hour work of great ambition and accomplishment. Its ostensible subject is the rule and overthrow of Ferdinand Marcos's regime in the Philippines, and the difficulties faced by the Corazon Aquino government afterward. Its real concern, however, is with the ability of mass media - video and television in particular - to shape public perceptions of political events on a national and internati onal level. In one sense, the work is a fast and furious display of recent Philippines history, mingling fact and observation with myth, rumor, and ironic TV grandstanding. In a deeper sense, it's an astute work of media criticism, as if a canny observer of contemporary life had chosen to dissect the pitfalls of TV journalism not by writing a book, but by making a TV show with its own perceptive and aptly oppositional approach. Video is obviously the perfect medium for such an undertaking, and Mr. Fagin has managed his endeavor with an aplomb that could make any visual artist proud. In addition to its other achievements, Fagin's work is a reminder that the interaction between media and audiences has received much study in recent years, and has prompted a lively debate between two camps: those who fear that mass-produced images result in mass-produced thinking and those who feel that spectators tend to have individual and often unpredictable responses to even the most regimented and manipulative material. The complexity of this debate, and the difficulty of finding neat answers, is suggested by Aimee (Rankin) Morgana's video "The Man in the Mirror," which focuses on Michael Jackson's aggressively mass-marketed public image. To what extent is a pop star a "private" personality, and how much do audiences project their own ideas and fantasies onto that personality when it confronts them in the media? There are no neat answers in Ms. Morgana's examination of this question, which raises issues as fascinating a s they are unresolved. Simpler in style but equally thought provoking is "A Spy in the House That Ruth Built," by Vanalyne Green, who wittily explores her female responses to the male-dominated world of baseball. Proving once again that feminist analysis can be original, penetrating, and very funny at the same time, this occasionally raunchy but consistently thoughtful video is one of the Whitney's most engaging finds. Also powerful is the chilling "Belladonna," by Ida Applebroog and Beth B, which blends quotations from psychologist Sigmund Freud, convicted child molester Joel Steinberg, and Nazi scientist Josef Mengele into a cautionary vision of humanity's most awful tendencies; and the beautiful "Volcano Saga," in which veteran artist Joan Jonas tells stories within stories relating to the place of women in ancient and modern cultures. Although the Whitney's film selections are fewer in number than the video offerings this year, there are some superb achievements to be seen, including works that realize the special capacity of film (as opposed to video) for capturing rich visual detail. None is more dazzling than Warren Sonbert's masterful "Friendly Witness" an exhilarating series of images accompanied by ingeniously chosen music ranging from rock to classical. This is a key work in Mr. Sonbert's long and amazing career should whet f ilmgoers' appetites for his subsequent effort, "Short Fuse," a dark and challenging film that will soon be appearing in adventurous cinema showcases. Another standout is Peter Hutton's silent "New York Portrait: Part III," which counterpoints the incipient chaos of contemporary urban life with the eloquence and supreme orderliness of its own superbly rendered imagery. Su Friedrich's autobiographical "Sink or Swim" is a personal tour through painful but revealing family experiences. "Cycles," by Zeinabu irene Davis, also deals with femininity in powerful visual terms. "The Deadman," by Peggy Ahwesh and Keith Sanborn, is a rampage into a savage world of lurking morbidity and unfettered sexuality, best approached with extreme caution by all but the boldest experimental-film watchers. Other works in the Whitney show range from the super-eight virtuosity of Lewis Klahr's fantastic "Tales of the Forgotten Future, Parts 2 and 3" and the postmodern complexity of Marlon T. Riggs's gender-bending "Tongues Untied" to the postpunk gloominess of Gregg Araki's aptly titled "The Long Weekend (O' Despair)" and the campy vulgarity of Charles Atlas's garish "Because We Must." Some entries have far more to offer than others, but taken together they amount to an instructive overview of film and video as complements rather than competitors.