Anamorphic Lenses: The Key to Widescreen Cinematic Imagery
What began as a tool and technique for capturing and projecting wider aspect ratios on 35mm film, anamorphic lenses are a runaway favorite among cinematographers for the unique characteristics they bring to moving images. Ultra-wide rectangular aspect ratios, long horizontal lens flares, and oval bokeh (the out-of-focus areas of the image) now feel as much a part of the cinematic experience as a bucket of popcorn and a liter of soda.
So how do anamorphic lenses work? The term anamorphic derives from the Greek words meaning "formed again." Compared to spherical lenses, which project a circular image onto the film or camera sensor, anamorphic lenses project an oval-shaped image. This is due to optical elements that squeeze more horizontal information from your scene. The captured image must then be stretched horizontally in post production, or in the projector, to be viewed at its intended aspect ratio.
Regular lens and bokeh vs. anamorphic len and bokeh
Traditionally, anamorphic lenses have a 2x squeeze, meaning that lenses capture twice the amount of horizontal information than a spherical lens. When stretched, a 2x anamorphic lens used with standard 35mm film yields a 2.39:1 aspect ratio, commonly referred to as CinemaScope, or simply "Scope." The desire for wider aspect ratios is what drove the popularity of anamorphic lenses in the film industry. In order to capture the same 2.39:1 aspect ratio with spherical lenses, it meant cropping, or "masking" the top and bottom of each frame, thus sacrificing vertical resolution.
For digital cinematographers working in HD or 2K formats, cropping a 2K frame to get a 2.39:1 ratio leaves you with a meager 858 lines of vertical resolution. Anamorphic lenses provide a means to capture a 2.39:1 ratio without having to make that sacrifice in resolution. However, due to the wider aspect ratio of digital sensors compared to 35mm film, 2x anamorphic lenses produce a super-wide 3.55:1 ratio, with a 1.5x anamorphic lens still producing an aspect ratio of 2.66:1. To produce a traditional "Scope" ratio with a 16:9 sensor, a 1.33x or 1.35x anamorphic lens is needed.
Companies like Letus and SLR Magic have developed 1.33x anamorphic lens adapters, which attach to the front of your lens. ARRI released a version of their popular Alexa camera with a 4:3 sensor, which is compatible with 2x anamorphic cinema lenses. Lens manufacturers such as Cooke and Angnieux recently produced their first anamorphic lenses. The ultra-widescreen cinematic look is still wildly popular among filmmakers.
Whether you're looking for streaking horizontal lens flares, made popular recently by J.J. Abrams, or you're going for that cinematic scope aspect ratio (without losing vertical resolution), anamorphic options in the digital cinematography world are stretching new horizons and I, for one, couldn't be more thrilled.