Rectaflex was the world's first series produced Pentaprism single lens reflex camera. It was produced from 1948 to 1958. Rectaflex was the only Italian single-lens reflex camera ever built. There has been some uncertainty about the Rectaflex being first or second pentaprism SLR to be produced. Marco Antonettos very thorough research in 2002 clarified that the Rectaflex was the first. Original Rectaflex The Rectaflex was a 35mm SLR camera with a Focal-plane shutter, interchangeable lenses and a pentaprism eye-level finder. It was the world's first SLR equipped with a pentaprism, with a final presentation in April 1948, and start of series production in September the same year, thus hitting the market one year before the Contax S, presented in 1949. It also had a wide diameter bayonet mount and a Rapid Return Mirror. The chief designer was Telemaco Corsi. The first prototype of the Rectaflex, presented at the Milano Fiera in April 1947, was a wooden mock-up, with a mirror eye-level finder, giving a left to right inverted image. For vertical pictures, the image was upside down, and that was a big drawback. This was corrected with a roof prism before the 1948 Milano show, and the preseries model was called Rectaflex Standard 947, and had a fully working pentaprism as well as a focal plane shutter from 1s to 1/1000, synchronised at 1/25. The first production model was the Rectaflex series A 1000 (serial number 1000 to 2150), quite similar to the preseries model. The Rectaflex series B 2000 (s/n some 2150 to 2999) added a split image device in the focusing screen and had no film cutter. Note that Rectaflex series A 1000 and Rectaflex series B 2000 were not official designations, but a way to recognize the variants by way of their serial number. The B 3000 series was produced from June 1949, and was numbered from 3001 to some 3970. The Rectaflex series B 4000 (s/n 4001 to some 4500) had a modified A/R lever. The Rectaflex series B 16000 (s/n 16001 to 16870) had a triple sync plug and a film reminder under the rewind knob. The Rectaflex series B 20000 (s/n 20101 to 20300) had an internally modified shutter and a reinforced bayonet mount. This was only a test series. The Rectaflex series 25000 (s/n 25000 to 29500) was produced from December 1952 and had a modified shutter to 1/1300, and two sync plugs