James H. (Jim) McNamara, 68, a prize-winning photographer on The Washington Post until his retirement in 1978 who was known for the ingenuity with which he pursued his work and the sharpness of his observations on the news business, died of pulmonary fibrosis Nov. 2 at the Washington Adventist Hospital in Takoma Park.

Despite a reluctance to enter his work in photo contests, Mr. McNamara won a number of awards from the White House News Photographers Association. In 1972, he received a first-place prize for a picture he took on June 4, 1971, of Curtis W. Tarr, then the director of the Selective Service System, fighting off a group of young war protesters who sought to "arrest" him in his office.

With superb timing, Mr. McNamara caught Tarr a split-second after he had delivered a right cross to one protester, who is falling to the floor. Another protester holding a pair of handcuffs stands to one side, giving balance and symmetry to the picture.

In an entirely different vein, Mr. McNamara won awards in the 1950s for pictures of new blossoms and of snow-covered houses in Georgetown.

In 1970, he took two memorable photos of Sen. Charles McC. Mathias (R-Md.) who was making an appearance in a barn. Mathias sought Mr. McNamara's advice on how to milk a cow. Mr. McNamara, a native of Brooklyn, N.Y., who was unfamiliar with dairy procedures, suggested that one of the cow's hind legs be raised for easier access to the udder.

Mr. Mathias tried this and Mr. McNamara took a picture of it. A moment later, the cow, whose name was Ballad, kicked the senator in the stomach and sent the milk pail flying. Mr. McNamara got a picture of Mathias retrieving the pail and laughing about the incident. Mathias asked for copies of these photographs.

Mr. McNamara moved to Washington in 1933 and went to work for the old Washington Times, later the Times-Herald. He was a photographer in the Marine Corps during World War II and saw combat in the Pacific, where he contracted malaria. After the war, he worked for the Associated Press here and in 1949 rejoined the Times-Herald. He came to The Post when this newspaper bought the Times-Herald in 1954.

Mr. McNamara thus learned his trade when times were hard, space in newspapers was at an even greater premium, perhaps, than it is today, and the essential ingredients in a day's work were shoe leather, patience, a readiness to forgo lunch, and a quick elbow.

These values remained a part of Mr. McNamara throughout his working life. Colleagues said he was possessed of a "Speed Graphic mentality," a reference to the large and heavy cameras that news photographers used to use and which had to be reloaded after each photograph.

For himself, Mr. McNamara was well known for his view that, if necessary, "you could cover all of World War II with two pictures: an overall shot of the action, and one of the winning general."

Mr. McNamara, who lived in Silver Spring, is survived by his wife, Jeannette; two sons, James H. Jr., of Ganado, Ariz., and Thomas, of Manassas, and two grandchildren.