There are two types of aerial photography, vertical and oblique.

An oblique aerial photography is taken at an angle, other than a right angle, to the ground. Both types of photography allow some interpretation of the picture, especially if the photography is repeated and changes can be identified.
Vertical aerial photographs are taken looking straight down to the ground, at a right angle, to produce an image that would appear as a map does.

Vertical photography is often prefered as it can be imported into a Geographical Information System (GIS) and used as a map base. Several datasets can be overlaid and changes can easily be seen. These changes can be digitised and quantified.

The quality and range of aerial photographs have developed over the years. Original photographs were in black and white and could only provide an approximate scale. Recent photographs are in full colour and can be accurately positioned and scaled. Along with this increased accuracy in position and scaling different types of film became available. False Colour Infra Red film allows vegetation to be better distinguised. These can also be used to detect features such as algal blooms, which may effect water quality. Below a false colour infrared image of East Fleet can be seen.

Aerial photographs play an important role in general mapping, as well as data acquisition and visualisation, they help provide a solid visual effect. Many people are more able to put spatial concepts into perspective when they see photos.