To meet the dual challenge presented to nonprofit organizations by recession and government-funding cutbacks, a Washington-based group called Independent Sector has picked up the gauntlet and run to the silver screen.

With aid from the producer of "To Fly" and a $300,000 Gannett Foundation grant, IS will make a film portraying the spectrum of activities by independent volunteer groups and how they contribute to American life. It will be available to IS member organizations, schools, libraries, community groups and for television broadcast.

Scheduled for December release, the film will be produced by Academy Award-winner Francis Thompson, whose films "To Fly" and "Living Planet" have been viewed by nearly 10 million people at the Smithsonian Institution's Air and Space Museum and at theaters around the country. His film "Energy Energy" is playing at the World's Fair in Knoxville.

IS is a 2-year-old coalition of foundations, corporations and nonprofits that serves as an information service and advocacy arm for its members in Washington.

According to IS spokesman John Thomas, the film is part of a major public information and education program that will focus on the "history and present breadth of the voluntary impulse in this country . . . and the role that the voluntary sector plays in making America unique."

Gannett Foundation President Eugene C. Dorsey said the notion of voluntary organizations needing greater definition in the public mind is one "whose time has come."

He quoted a recently released Independent Sector study on the impact of the Reagan administration budget cuts on the voluntary community as evidence of the need to stimulate individual contributions of time and money.

According to the IS study, corporations, foundations and individual bequests compose only 15 percent of the money given to voluntary organizations, while individuals make up the other 85 percent.

This, Dorsey said, demonstrates the "crucial" need for the development of individuals as a continued source of gifts and initiative for the independent, voluntary sector.

Regarding his involvement in the film, Thompson said he was initially impressed with the concept of a film that clarified the actions of the independent voluntary sector as distinct from the business and government sectors. "I don't think any of us had sorted it out," he said.

Thompson said the theme of voluntarism as part of the American way of life will be portrayed in a variety of ways. The film's emphasis, however, will be decidedly upbeat, depicting how people donate their time to the full range of independent, voluntary organizations.

He said one of the possible combinations might be a picture of a symphony orchestra with a quick cut to a smaller, more familiar institution, the volunteer fire department.

Thompson said he was impressed by the sheer numbers of organizations engaged in voluntary activity. The possibilities are endless, he said, "if you pick up the Manhattan phone book and look under the heading 'association of' you get an idea of what I mean."