[1] It is notable for having been the first mass-produced theater projector in which 4/35 and 5/70 prints could be projected by a single machine, thereby enabling wide film to become a mainstream exhibition format, for its recognition in the 1963 Academy Awards, which led to it being described as "the only projector to win an Oscar" (though this is technically incorrect, because the award was actually a Class 2 Oscar Plaque), and for its longevity: a significant number remained in revenue-earning service as of February 2014.
Small-scale attempts had been made to use wide film for commercial theater exhibition around the time of the conversion to sound, of which Fox Grandeur was technologically the closest to the format the DP70 was designed to facilitate the launch of, two decades later.
The DP70 (DP stands for "Double Projector") was invented and developed by a team headed by Jan-Jacob Kotte of Philips between 1952 and 1954, as part of the Todd-AO system.
As a result of the machine's success, dual gauge projectors were quickly developed and launched by Philips's main competitors, including Cinemeccanica of Italy and Century of the United States.
All the projector mechanisms were built at the Philips factory in Eindhoven, though much of the peripheral hardware for the machines that were exported to the United States, e.g. bases and reel magazines, was manufactured locally, initially by the American Optical Company and later by Ballantyne.
Jan-Jacob Kotte believed that the use of heavier materials to absorb vibration reduced instability in the projected image, and this is certainly reflected in the design of the DP70: a complete outfit, including the bases and reel magazines, weighs 1,004 lbs – which is half a ton.
The DP70 was also significantly more expensive than any single gauge theater projector on the market: a US customer was quoted $6,225 for one in 1966 ($44,942 in 2014, adjusted for CPI inflation), which was around the cost of a typical three-bedroom suburban home at the time.
The change of gauge is done by swapping some gate components, pad roller assemblies, reel spindles and the lens, and in some cases making minor adjustments to the lamphouse.
Because the DP70 was intended for use with 70mm film and in large theaters with a long throw to a big screen, several features were included to disperse the intense heat generated by the more powerful lamps with which it was often used.
Because many of the DP70s remaining in use today are in repertory venues that screen a wide range of formats, including prints of silent movies that require a lower frame rate than 24, very many have now received aftermarket modifications that will typically enable any speed between 16 and 30.