Film & Sensor Sizes

Sensor & Film Formats size comparison

Photopedia

14 July 2008 16:50

This list of film formats and sensor sizes is in no way exhaustive, it represents the most common sizes of both light sensitive surfaces.

Film

10x8"
5x4"
6x9cm
6x7cm (56×70 mm, enlarges onto 10x8 paper perfectly)
6x6cm
6x4.5cm
35mm (24 × 36 mm)

Sensors

Medium Format (Kodak KAF 3900 sensor)
50x39mm
35mm ‘Full Frame'
36x24mm
APS-H (Canon) 28.7x19mm
APS-C (Nikon etc.) 23.6x15.7mm
APS-C (Canon)
22.2x14.8mm
Foveon (Sigma) 20.7x13.8mm
Four Thirds System 17.3x13mm
1/1.7"
7.6x5.7mm
1/1.8"
7.18x5.32mm
1/2.5"
5.76x4.29mm

CCD or CMOS sensors convert light entering the camera into a digital image. They’re most often smaller than or equal to 35mm film, although the sensors used in medium and large format digital backs are larger than this.

Film formats and film grain are in a way comparable to sensor size and number of megapixels, although digital photography also deals with sensitivity in the form of ISO. Larger film formats require less magnification at the printing stage, thus ensuring better image quality than a smaller format using the same film stock.

For digital sensors, there is a direct relationship between the size of the CCD, the number of megapixels it supports and individual pixel size. The larger the pixel, the more light energy it accumulates during exposure. This means that sensors with larger pixels are more sensitive to light than those with smaller pixels, and produce less image noise.

There are several reasons why all digital cameras don’t have sensors that are at the larger end of the scale. The first is simply cost; larger CCDs are more expensive to produce. Secondly, like film formats, as the CCD size increases, the optical requirements of the camera change, lenses and depth-of-field are directly affected. The final reason is then the desired size of the camera. Requiring larger optics inevitably requires a larger camera body, which is obviously not ideal in the world of the compact camera.