Aspect/Ratio and Arrangement Guidelines

The Aspect/Ratio is the ratio of the width to the height of the image on the screen. Projects shot on film are able to be finished and detailed in a vast variety of ways. Aspect Ratios are expressed as a ratio, the larger the number, the wider the image All standard definition screens (NTSC and PAL) have an aspect ratio of 1.33, with a broadcast format referred to as 4x3. HD screens have an aspect ratio of 1.78, with a broadcast format referred to as 16x9. Not to be mixed up: aspect ratio describes the shape of the frame, while broadcast format refers to the shape of the television monitor.

A camera ground glass inscribed with the desired aspe ct ratio allows the Director of Photography can masterfully compose the shot, sequence, or film. Any aspect ratio can be displayed on any broadcast format in many ways, but some must be modified to fit the screen. The four most prominent methods are Letterboxing, Pillarboxing Center Extraction, and 16x9 Vertical Squeeze.

Letterboxing (top and bottom mattes)

To properly display 1.78, 1.85 and 2.40 aspect ratios on an SD (4x3) monitor, mattes are applied during the video transfer to the top and bottom of the screen. These mattes cover “unwanted” image area, so the entire frame can be moved up or down to perfect the framing of each shot. 1.78 images completely fill an HD (16x9) monitor and don’t need letterboxing. 1.85 and 2.40 aspects will require mattes in 16x9 as well. Although the entire screen is not being used, letterboxing preserves the original framing and aspect ratio.

Pillarboxing

This is for 16x9 displays only. TO display th eentire frame exposed in camera (1.33 for S35, 1.78 for Academy 35, or 1.66 for S16), there must be a matte on the left and ride sides of the image. This allows the square aspect of these formats to display within the wider aspect monitor, without stretching or distoring the image.

Center Extraction (cropping)

This method alters the original framing by cropping off the left and right sides of the frame to completely fill the sreen with image. Typically a pan-and scan pass must be done to correct for undesirable cropping, even if framing precautions were taken during the shoot.

16x9 Vertical Squeeze

1.78 or 2.40 aspect ratios are maintained by squeezing the image into the entire area of the 4x3 screen. 16x9 monitors will unsqueeze the image, displaying the full frame in the proper aspect ratio.

Anamorphic Cinematography

Filming with an anamorphic lens creates a squeezed image on the negative. During the telecine transfer, the image is electronically unqueezed to produce an image with the proper 2.40 aspect ratio. Transferring for 4x3 or 16x9 displays can be done using a letterbox matte (no cropping) or center extraction (cropping).

Super 35 (full aperture) and Standard 35 mm (academy aperture)

Standard 35mm leaves a small portion of the left side of the negative unexposed, to allow room for a soundtrack on theatrical prints. Super 35mm exposes the entire negative from perf to perf, allowing a variety of compositions with less grain and more detail. The most common theatrical formats are 1:85 (aka flat) and 2.40 (aka scope, short for cinemascope). Informing your post house that you shot super 35 tells them you centered the image on the negative, which is helpful knowledge for a proper telecine transfer. It is also crucial to shoot a framing chart and provide clear instructions to eliminate any confusion during the post production process regarding aspect ratios and intended framing for either format.

Super 16 mm

Super 16 is a very popular acquisition format for HD finish. Super 16 can save money on the front end, with less film stock and processing. The native 1.66 aspect ratio is typically cropped to 1.78 or 1.85, yielding a high quality image with the aesthetic benefits of film origination.