Editing Large format (section)

===National Park Service documentation programs===
Large format film is also used to create a record of historic places and things for the [[National Park Service]] documentation programs. The [[Historic American Buildings Survey]]&nbsp;(HABS), the [[Historic American Engineering Record]]&nbsp;(HAER), and the [[Historic American Landscapes Survey]]&nbsp;(HALS) require large format film-based photography. 4×5″, 5×7″, and 8×10″ large format film formats are the only acceptable formats for inclusion in these collections at the [[Library of Congress]]. 4x5 and 5x7 are generally used in the field (5×7″ is preferred for very significant buildings) and 8×10″ is generally used for photo-duplication of historic photographs, documents and blueprints. Through HABS/HAER/HALS, buildings and sites of historic significance are recorded with large format cameras and black and white film and using techniques that document the key features of the historic resource with special care not to distort the angles and views. This rectified photography can be accomplished with large format cameras by keeping the film, lens and subject perfectly parallel. Smaller format cameras need to be tilted to view high or low subjects, but the same subjects can be captured by shifting the lens element of a large format camera up or down to keep the film, lens, and subject planes parallel.

HABS, HAER, and HALS also requires the increased resolution of large format film. A sheet of 5×7″&nbsp;film has almost twice the resolution of 4×5″ film, and 4×5″ is almost 16&nbsp;times larger than a 35&nbsp;mm film image (24×36&nbsp;mm). This added negative size not only allows for more detail, but the large format [[polyester]] film is also far more durable than [[acetate]] 35&nbsp;mm stock. HABS, HAER, and HALS require that all submissions to the Library of Congress include the original film (archivally washed) and it must also include contact prints on fiber-based paper; these contacts are the same size as the film being submitted, 4×5″, 5×7″, or 8×10″, and the large size allows people to readily see the prints, while 35&nbsp;mm contacts would be too small and would require magnification.