Aerial Photography: Reliability and Uses of Information Page 3 of 3   Categories of Aerial Photographs Aerial photographs are usually classified as either vertical or oblique, each with their own advantages and disadvantages. A vertical photograph made with a single-lens frame camera is the most common type used in remote sensing. Vertical photographs are made with the camera axis directed as vertically as possible. A "truly" vertical aerial photograph is rarely obtainable because of unavoidable angular rotations or tilts caused by the angular attitude of the aircraft. These unavoidable tilts cause a slight 1 to 3 degree inclination thus resulting in tilted photographs. These unintentionally tilted photographs are referred to as "vertical" and are treated as such without serious error. However, when aerial photographs are taken with an intentional inclination of the camera axis oblique photographs result. Compare these vertical and oblique photographs The next section deals with the manner of interpreting aerial photographs. Aerial Photography: Interpretation   | 1 | 2 | 3 | Page 3 of 3