The Zeiss Standard T. 2.1 are 35mm format lenses developed by Carl Zeiss for ARRI (then Arriflex), and predate the original Zeiss T. 1.2 High Speed series (Super Speed in the U.S.). Information on when the original set was introduced is hard to come by. A safe guess is after 1964 and before 1975. It is likely that this set was just called something like the “Zeiss Standard T. 2.1 Primes for Arriflex”, and once the High Speed lenses were introduced in 1975, they became the well known in the world “Standard Primes”. The Zeiss Standard T. 2.1 are comparable in size to the Cooke Speed Panchro but are a more modern design and significantly exceed the optical performance (on the technical merits) of the older Speed Panchros. Focal lengths in the original series are Distagon 16, 24 and Planar 32, 50 and 85mm. An 8mm focal length for 16mm format was also available. The small size of the Zeiss T. 2.1 barrels allowed three of them to be mounted simultaneously on the 3-lens turret of the ARRI 35IIB/C cameras. Zeiss Standard T. 2.1 also fit inside the prime lens blimp of the Arriflex 35BL I/II.