The most common question I get is about using anamorphic lenses on Super 35-sized sensors and what exactly the results would be. The ARRI ALEXA 4:3/XT and RED EPIC/DRAGON both have an anamorphic de-squeeze feature in them for proper viewing on set, and are the most popular digital cameras to use in this way, by far. In addition, Sony recently added an anamorphic de-squeeze mode to their F5 and F55 cameras, and the new Phantom Flex4K has this option, as well. These cameras each have different sensor sizes, based on their designs and recording modes, so things can get a bit confusing. Each camera will produce a different image in its anamorphic mode, as they each have unique crop factors. To understand how this works, we should first dive into the history of anamorphic, why it was developed and how we use it today.
SQUEEZING IT INThe first major use of anamorphic lenses for cinema production was in the 1950s when 20th Century Fox developed CinemaScope. CinemaScope used anamorphic lenses to literally squeeze a widescreen image onto existing 35mm film. Fox was looking to increase theater ticket sales, which were heavily impacted by television. CinemaScope used anamorphic lenses to squeeze a widescreen image onto the existing 4-perf 35mm Academy ratio film stock used at the time. Traditional anamorphic lenses squeeze the image 2:1 horizontally, and then lenses were used on the projection side to de-squeeze the image back to normal.
35mm film at the Academy ratio had an aspect ratio of 1.375:1, very close to 4:3 television, because a good chunk of the film stock was used for audio waveforms. In the illustration, notice that the Academy format 35mm film frame was 22mm wide by 16mm high. CinemaScope used slightly more film vertically (18.6mm), but the same 22mm width. The 22mm width was effectively doubled by the anamorphic lens, so the aspect ratio of CinemaScope was 44/18.6, or around 2.35:1. After adjustments were made for projection, the final aspect ratio was just around 2.39:1.
Fox made several pictures with their CinemaScope system, and even licensed it to Disney to make 20,000 Leagues Under the Sea. The system had many problems, though, as the anamorphic elements in the lenses tended to stretch actors’ faces as they got closer to camera. These optical flaws pushed many cinematographers away from CinemaScope, but Panavision saw the demand, fortunately, and produced their own anamorphic lenses. The Panavision lenses were designed to produce the same 2x squeeze on Academy format 35mm film, but had far fewer optical issues. By 1967, at the demand of Frank Sinatra, so legend has it, even Fox had moved to the Panavision lenses. This marked the end of the original CinemaScope lens system, but the basic film format still lives on today.