Deep Focus - Deep Focus and Different Formats

Deep Focus and Different Formats

The choice of shooting format affects how easy it would be to achieve a deep focus look. This is because the size of the sensor or film gauge dictates what particular lens focal length would be used in order to achieve a desired viewing angle. Smaller sensors or film gauges will require an overall range of shorter focal lengths to achieve any desired viewing angle than larger sensors or film gauges. Because depth of field is a characteristic of lens focal length (in addition to aperture and focus distance setting), it is easier to achieve a deep-focus look with a smaller imaging sensor or film gauge. For example: a 40mm lens will give a 30-degree horizontal angle of view in the Super35 format. To achieve the same viewing angle with a 1/2" 16:9 sensor, you would need a 13mm lens. A 13mm lens inherently has much more depth-of-field than a 40mm lens. To achieve the same depth of field with a 40mm lens would require a very small aperture, which in turn would require far more light, and therefore time and expense.

Some filmmakers make deliberate use of the deep focus aesthetics of smaller-than-35mm digital formats. Miami Vice (Michael Mann, 2006) is among the many big budget movies that have been shot digitally in recent years. Cinematographer Dion Beebe had this to say:

We also decided that there were attributes of HD technology we liked and wanted to exploit, like the increased depth of field. Because of the cameras' chip size (2/3"), they have excessive depth of field that we decided not to fight, but rather utilize.