Monday, February 25, 2008

The why of aspect ratios

We hear about aspect ratios and their importance in our work. It's so important that both George and I spend a section of our books on the subject and how it impacts our work. But, why is aspect important? Where did this thing begin? We turn to InfoComm for the answer:

"It all started in the early 1900's in the film industry, when professional movie film widths and frame sizes were formalized with the 35-mm width accepted as standard in Europe and in the United States. This shape was standardized by the Academy of Motion Picture Arts and Sciences in 1927, and became known as the ''Academy'' format. Each frame measured 0.825 inches wide by 0.600 inches high (20.96mm wide by 15.24mm high), and spanned 4 sprocket holes on the film. Images were thus framed in the approximate 4 to 3 ratio of width to height - four units wide and three units high."

Sometimes, we get commercially produced films and DVDs for use in court. In order to process them correctly, we have to account for aspect ratio. Here are some common aspect ratios seen in commercially produced films/movies:

1:1.50 - vertical 35mm slides
1:1 - overhead transparencies
1.33:1 - standard video, 16mm, most computers (4x3)
1.50:1 - horizontal 35mm slide (3x2)
1.78:1 - HDTV (16x9)
1.85:1 - Panavision / Letterbox
1.96:1 - VistaVision
2.35:1 - CinemaScope
2.76:1 - Cinerama

(note: the first number in the ratio is always the width)

For those unfamiliar with InfoComm, they offer an outstanding array of training to the commercial AV industry and are worth a look.

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