The most common type of camera today,
35mm cameras were invented in 1914 by Oskar Barnack, and made commercially available by
Leica in 1925. In the decades since then, literally hundreds of companies have produced a large variety of 35mm cameras, ranging from "single use" disposable cameras to professional-level
SLR systems. As implied by the name, these cameras use 35mm-wide film, spooled into light-tight cartridges. Most 35mm cameras record 24 by 36mm images on the film, but alternate formats (such as 24 x 32mm and 24 x 18mm) do exist. The 35mm format provides a comfortable balance between image clarity, camera size, and affordability that has made the format popular with professional and amateur photographers.