The Early Aviation Photograph Collection is a collection of unknown origins consisting of 328 black-and-white photographic prints and 299 negatives primarily depicting aircraft from the first half of the 20th century. Some airships, airports, pilots, and other subjects are also depicted in the photographs. The collection is arranged into two series: Airplane photographs and Non-airplane photographs.

The first series, Airplane Photographs, makes up the bulk of the collection with 156 prints and 281 negatives. The images depict aircraft from a variety of American and European manufacturers including Blackburn, Bleriot, Boeing, Caproni, Curtiss, De Havilland, Dornier, Douglas, Fokker, Hawker, Lockheed, Loening, North American, Northrop, Vickers and Waco, among others. The photographs predominantly depict planes on the ground with front, side or three-quarters views. However, some images are of planes inflight or with people. The folders of images of the Douglas O-38 include several photographs depicting planes from the California National Guard. Among the images of Lockheed aircraft are folders with nearly 80 images depicting production of their aircraft, including images with factory workers and details of aircraft.

The second series, Non-Airplane Photographs, is smaller with 172 prints and 18 negatives. This series consists of a mix of subjects, including people, places, and other types of aircraft. Lighter-than-air aircraft, balloons, and dirigibles are well represented with 26 images total, including photographic reproductions of older illustrations. The first air show in Paris in 1909 is represented with 11 images, probably copied from a book or clippings. A few locations in California are depicted including the Alhambra airport; Pasadena, with aerial views; balloons at Ross Field; as well as Chaplin Airlines, which provided service to Santa Catalina Island. There are more than 120 photographs of assorted people, male pilots, and female pilots, including formal portraits, group portraits and casual snapshots. However, aside from one image of Florence "Pancho" Barnes with other women pilots, the people in these images are all unidentified. Identified people were separated into folders by name. Some of the photographs of people do also include airplanes.

The majority of negatives are 8x10 inches, although some are 5x7 inches. The prints vary in size but are all 8x10" or smaller. All images are black-and-white. There is some duplication between prints and negatives, though not all prints have negatives or vice versa. Many folders also include clippings or copies of articles related to the images.