This lens was constructed by using a Distagon 16mm 2.1 with a permanently attached aspherical front element (aspheron) and carried ARRI branding. All standard Zeiss primes exhibit some positive focus shift when stopping down. This is indicative of a “relaxed” correction of spherical aberration, especially on the older designs, which is associated with pleasing bokeh.
ZEISS STANDARD SPEED PRIME LENSE
12mm / T2.1 / cf 10” / Front Diameter: 135mm