Documentary filmmaker Michael Blackwood will introduce his most ambitious work to date, "Masters of Modern Sculpture," a three-part series tracing sculpture from Rodin through di Suvero, Christo and Smithson, at a free lecture tonight at 8 o'clock at the Hirshhorn Museum. The lecture will be followed by a screening of the first movie in the series, "The Pioneers." The other two parts are called "Beyond Cubism" and "The New Wrold." Each runs 58 minutes and will be shown free at the Museum this month.

"The pioneers" is scheduled for additional showings at noon on Thursday, May 11, and 1 p.m. on Saturday, May 13. "Beyond Cubism" will be shown Friday at 8 p.m. Thursday, May 18, at noon and Saturday, May 20, at 1 p.m. "The New World" screens Saturday at 1 p.m. and at noon on Thursday, May 25, and 1 p.m. on Saturday, May 27.

John Korty's "Who Are the DeBolts and Where Did They Get 19 Kids?" - the Academy Award winner in the feature documentary category - will be shown this afternoon as part of an International Rehabilitation Film Festival sponsored by Rehabilitation International USA at the Washington Hilton. "The DeBolts" concerns a San Francisco Bay area couple whose prood includes 15 adopted children, many of them physically handicapped war orphans.

"The DeBolts" will conlcude an approximately four-hour program of films scheduled to begin at 1:30 p.m. in the Monroe Ballroom. A second program of documentaries on the subjects of treating and living with physical handicaps and disabilities is scheduled for Friday at 9 a.m.

The Council on Foundations is currently convening at the Shoreham Americana, and screenings of documentary films sponsored by foundations are part of the proceedings. Showings begin at 9:10 a.m. in the Colonial Room, located in the East Lobby, and continue through 4:30 p.m. today. The subjects include Albert Schweitzer, women, heart attacks, Indian rights, a country doctor, housing and labor strikes.

Lawrence H. Suid, the author of an upcoming book about Hollywood war melodramas called "Guts and Glory: Great American War Movies," will conduct a film-and-lecture series on the subject at the Martin Luther King Memorial Library beginning Monday, May 8. The six-week series will include showings of such films as "Bataan," "The Battle of san Pietro," "Destination Tokyo," "Memphis Belle," "Sands of Iwo Jima," "The Green Berets," "The Selling of the Pentagon" and "Hearts and Minds." The location is Room 216 from 6:30 to 9 p.m. Call 727-1271 for information about regiatration.