(a) Vertical : If optical axis of the camera is held in a vertical or nearly vertical position.
(b) Tilted : An unintentional and unavoidable inclination of the optical axis from vertical produces a tilted photograph.
(c) Oblique : Photograph taken with the optical axis intentionally inclined to the vertical. Following are different types of oblique photographs:

(i) High oblique: Oblique which contains the apparent horizon of the earth.
(ii) Low oblique: Apparent horizon does not appear.
(iii) Trimetrogon: Combination of a vertical and two oblique photographs in which the central photo is vertical and side ones are oblique. Mainly used for reconnaissance.
(iv) Convergent: A pair of low obliques taken in sequence along a flight line in such a manner that both the photographs cover essentially the same area with their axes tilted at a fixed inclination from the vertical in opposite directions in the direction of flight line so that the forward exposure of the first station forms a stereo-pair with the backward exposure of the next station.

(a) Small scale - 1 : 30000 to 1 : 250000, used for rigorous mapping of undeveloped terrain and reconnaissance of vast areas.
(b) Medium scale - 1 : 5000 to 1 : 30000, used for reconnaissance, preliminary survey and intelligence purpose.
(c) Large scale - 1 : 1000 to 1 : 5000, used for engineering survey, exploring mines.