For many this will be dictated by what is available but if some wishes to purchase an aircraft solely for the purpose of Oblique Aerial Photography there are many factors, which should be taken into consideration.
Firstly and foremost the aircraft must be legal. Therefore, if revenue is generated from the flight that is greater than the cost of the flight the aircraft must hold a valid Public Transport Certificate of Airworthiness. This is because aerial photography is put in the class of ‘Aerial Work’ and thus must conform to the guidelines set out by the CAA.
Most high wing light aircraft can be used for oblique Aerial photography but there must be a compromise between efficiency and speed. While a Cessna 182 will have a relatively high cruise speed and will have less flight time between sites the fuel burn and therefore cost per hour will be much greater. In comparison a Cessna 152 will have a much slower cruise speed but will be much lighter and therefore will burn less fuel per hour. The initial outlay for a 152 would also be less and therefore less finance is needed to get the operation off the ground!
Although the Cessna range of aircraft has a proven track record there are other options for an Aerial Photography business. For instance an aircraft such as a piper cub may be used. However, there is generally less space for equipment in an aircraft of this type.
There are obviously occasions when a Cessna is not appropriate for Aerial Photography work, such as central London sites where a twin engine is required and often a Helicopter is preferred as it is much easier to stop and hover while waiting for clearances.