The first practical reflex camera was the Franke & Heidecke Rolleiflex medium format TLR of 1928. Though both single- and twin-lens reflex cameras had been available for decades, they were too bulky to achieve much popularity. The Rolleiflex, however, was sufficiently compact to achieve widespread popularity and the medium-format TLR design became popular for both high- and low-end cameras.

A similar revolution in SLR design began in 1933 with the introduction of the Ihagee Exakta, a compact SLR which used 127 rollfilm. This was followed three years later by the first Western SLR to use 135 film, the Kine Exakta (World's first true 35mm SLR was Soviet "Sport" camera, marketed several months before Kine Exakta, though "Sport" used its own film cartridge). The 35mm SLR design gained immediate popularity and there was an explosion of new models and innovative features after World War II. There were also a few 35mm TLRs, the best-known of which was the Contaflex of 1935, but for the most part these met with little success.

The first major post-war SLR innovation was the eye-level viewfinder, which first appeared on the Hungarian Duflex in 1947 and was refined in 1948 with the Contax S, the first camera to use a pentaprism. Prior to this, all SLRs were equipped with waist-level focusing screens. The Duflex was also the first SLR with an instant-return mirror, which prevented the viewfinder from being blacked out after each exposure. This same time period also saw the introduction of the Hasselblad 1600F, which set the standard for medium format SLRs for decades.

In 1952 the Asahi Optical Company (which later became well known for its Pentax cameras) introduced the first Japanese SLR using 135 film, the Asahiflex. Several other Japanese camera makers also entered the SLR market in the 1950s, including Canon, Yashica, and Nikon. Nikon's entry, the Nikon F, had a full line of interchangeable components and accessories and is generally regarded as the first Japanese system camera. It was the F, along with the earlier S series of rangefinder cameras, that helped establish Nikon's reputation as a maker of professional-quality equipment.

Analog electronic cameras
TLRs and SLRs
Kodak and the birth of film
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