Understanding Anamorphic Lenses

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I suspect that there are many on the site who know a lot about anamorphic lenses, but I also suspect that there are very many who don't – and while I know some things, I can always learn more.

One of our readers mentioned this article to me on twitter and I found it very valuable and knew many of you would too. It comes from Red.

Understanding Anamorphic Lenses

Via Red.com:

Anamorphic lenses are specialty tools which affect how images get projected onto the camera sensor. They were primarily created so that a wider range of aspect ratios could fit within a standard film frame, but since then, cinematographers have become accustomed to their unique look. This article discusses the key considerations with anamorphic lenses in the digital era.


Overview

Two classes of lenses are typically used in production: spherical and anamorphic. Spherical are more common and are the assumed lens type unless specified otherwise. Spherical lenses project images onto the sensor without affecting their aspect ratio. Anamorphic lenses, on the other hand, project a version of the image that is compressed along the longer dimension (usually by a factor of two). Anamorphic lenses therefore require subsequent stretching, in post-production or at the projector, in order to be properly displayed.

Anamorphic lenses 1

Motivation

Anamorphic lenses were originally designed so that wide format imagery would fully utilize the film area of standard 35 mm frames. Otherwise wide format imagery would have left the top and bottom of the frame unused, and required cropping these out using masks in the projector:

Anamorphic lenses 2

Note: Above frames are shown to scale for SMPTE 195-1993 at 2.39:1 (“2:40”) widescreen. Usable area is 184 mm2 for standard widescreen and 367 mm2 for anamorphic. Relative area increase is 100%.

Anamorphic lenses therefore improved image quality by both enhancing vertical resolution and reducing the appearance of grain. For example, using a standard spherical lens to capture 2.40:1 imagery on 35 mm film only utilizes 50% of each frame’s area. With anamorphic, 100% of the frame area contributes to the final image.

Read full article at Red.com “Understanding Anamorphic Lenses”

Note: it is our policy to give credit as well as deserved traffic to our news sources – so we don't repost the entire article – sorry, I know you want the juicy bits, but I feel it is only fair that their site get the traffic and besides, you just might make a new friend and find an advertiser that has something you've never seen before

(cover photo credit: snap from source in post)


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