Anamorphic lens attachment mounted behind the prime lens, producing 2:1 horizontal squeeze. Delivers cleaner images than front anamorphic while preserving characteristic lens flares.
Definition
The Rear Anamorphic is an anamorphic lens system that is mounted behind the camera's main lens and creates a horizontal squeeze of 2:1. Unlike front anamorphics, it sits between the lens and the sensor/film, compressing the already focused image. The term is derived from "Rear" and the Greek "anamorphosis" (transformation).
Technical Details
Rear Anamorphics operate with a compression factor of exactly 2:1 and are typically used with T-stops between 2.8 and 4.0. The system consists of cylindrical lens elements that refract only in one axis, thus creating the characteristic horizontal compression. Modern rear anamorphics from manufacturers like ARRI or Cooke achieve resolutions of over 6K and cover Super35 as well as large format sensors. The backfocus must be precisely set to 52mm (PL-Mount) or 46.5mm (LPL-Mount) to ensure correct focus.
History & Development
Development began in 1952 at Bausch & Lomb for 20th Century Fox's CinemaScope system, initially using only front anamorphics. Rear anamorphics emerged in the 1970s as a response to the optical limitations of front systems. Panavision revolutionized the industry in 1979 with the first professional rear anamorphic system. In 2016, ARRI introduced integrated rear systems with their Master Anamorphic lenses, which are now standard in high-end productions.
Practical Use in Film
Ridley Scott used rear anamorphics for "Blade Runner 2049" (2017) to create the characteristic horizontal lens flares and oval bokeh circles. Denis Villeneuve employed them in "Dune" (2021) to achieve the 2.39:1 aspect ratio while maintaining sharp wide-angle shots. The workflow requires de-squeezing in post-production from 2:1 to the final 2.39:1 format. Advantages include less vignetting and better corner sharpness compared to front anamorphics, while disadvantages include higher calibration effort and limited lens compatibility.
Comparison & Alternatives
Front anamorphics produce stronger optical artifacts and distortions but are more universally applicable. Rear systems deliver technically cleaner images while retaining anamorphic characteristics. Spherical lenses with sensor cropping offer a 2.39:1 aspect ratio without optical compression but lose 30% of the sensor resolution. Large format cameras like the ALEXA LF have enabled anamorphic shooting with a larger sensor area and reduced depth of field since 2018.