Aerial photography records the ever-changing cultural and natural features on the Earth's surface. Air photos capture residential and industrial areas, road and rail networks, and geographical features including mountains, canyons, flatlands, rivers, lakes, forests, and cropland. Aerial photography has many practical applications such as map-making, urban and rural planning, environmental impact studies, civil law cases, real estate evaluations, and can even be used as wall art.

This material will help you understand the fundamentals of aerial photography by explaining some basic technical concepts and providing many samples of the images available from the National Air Photo Library (NAPL) of Natural Resources Canada. It also introduces air photo interpretation and provides advice on how to search for and purchase aerial photographs from NAPL.

The National Air Photo Library has a range of products available, from hard-copy contact prints to high-resolution digital images scanned from air photos.

Contact prints are photographs (black and white or colour) made from film negatives, and exposed on 25cm x 25cm (10"x10") matte photographic paper. A less expensive but lower resolution alternative is to produce a laser-copy of the photo on high-gloss paper using the Library's high quality greyscale/colour photocopier.

Air Photo Enlargements can be made to customized scales, and are useful when an enlarged image of an area is required. Generally, photos can be enlarged up to five times with excellent results. Enlargements are exposed on matte photographic paper, with sizes ranging from 25cm x 25cm (10"x10") up to 101cm x 152cm (40"x60").

Digital Air Photos are contact prints scanned at high resolution and saved in raster format. They can be used in computer graphics software or geographic information systems, and enlarged or reduced for easier analysis of study areas. These images can be published in reports or on websites (with copyright approval).