35mm : There are two formats with this film the most widely used is 24mm x36mm but there are some cameras that take half frame images which is about half this size and allows for twice as many shots per standard roll of film. The film from edge to edge including the perforations measures 35mm.

The use of the film was first established in Thomas Edison's lab by William Dickson, who took 70 mm film stock supplied by the Kodak Eastman Company. The 70 mm film was cut lengthwise into two equal width (35 mm) strips, spliced together end to end, and then perforated along both edges. The original picture size was 18 x 24 mm, which in modern times is considered to be a "half-frame" format.

If we look at the ratio fo the frame - the 36 x 24 format is quite close to the ratio 34 x 21 from the Fibonacci series.

From the 1970s the 35mm SLR camera became a standard piece of equipment that mass culture embraced through to the introduction of digital technology in the late 1990s.

Compared to larger formats, the cameras are very portable, light and easy to maneuver - many brands like Nikon, Canon etc. also developed a huge rage of accessories and lenses that fitted onto a camera body.