Shooting a beauty promo on Arri/Zeiss Masterprimes. Undoubtedly my favourite of the fast primes out there. Their performance at T1.3 (where we shot everything) is famously undiminished. Whereas most 'super-speed' options are noticeably different wide open (softer, chromatically compromised, distorted) the Masterprimes remain world class. Focus depth aside, they exhibit very little optical difference between say T1.3 and T5.6
Their engineering is also such that an AC can actually manage the sliver of focus that T1.3 offers. Their internal cams ensure that the focus does not overly accelerate as you approach minimum focus and the throw remains steady. We repeated a series of slow dolly moves towards our subjects on a 40mm... you cant really ask this focus accuracy of an AC on say a set of Super Speeds.
There is obviously an enormous amount of emotion that goes into lens description, many opting for the baked-in 'look' that some primes offer. I personally find its a better place to start sharp and undistorted, and then diffuse to taste rather than inherit an optical fog wide open. The lack of 'lens' in the look of a Masterprime, the absence of distortion , vignette, veiling glare and edge fall-of perhaps make them the most 'naturalistic' lenses out there... and the least
Production stills by Mauro Carraro