Toronto. Even before 1839, optical houses created various lenses from glass for the apparatus of the day. After 1839, lens design and quality became the defining factor of camera quality.
Most optical institutes such as Zeiss provided lenses to a multitude of makers. Some institutes however, offered only a few lens designs of reputedly superior quality. For example, Leitz created for its Leica what they claimed were high quality lenses. When the bayonet model Leicas were introduced after the second war, lenses were named for their widest aperture. A summicron was f/2 for example, and came in various focal lengths. In later years Leitz added -M for lenses designed for their bayonet cameras and Apo- for lenses that brought three primary colours into a flat image plane. Continue reading

















