Practical Limitations
In motion picture formats, the physical size of the film area between the sprocket perforations determines the image's size. The universal standard (established by William Dickson and Thomas Edison in 1892) is a frame that is four perforations high. The film itself is 35 mm wide (1.38 in), but the area between the perforations is 24.89 mm×18.67 mm (0.980 in×0.735 in), leaving the de facto ratio of 4:3, or 1.33:1. A 4:3 ratio mimics human eyesight visual angle of 155°h x 120°v, that is 4:3.075, almost exactly the same.
With a space designated for the standard optical soundtrack, and the frame size reduced to maintain an image that is wider than tall, this resulted in the Academy aperture of 22 mm × 16 mm (0.866 in × 0.630 in) or 1.37:1 aspect ratio.
Read more about this topic: Aspect Ratio (image)
Famous quotes containing the words practical and/or limitations:
“To the men of this world, to the animal strength and spirits, to the men of practical power, whilst immersed in it, the man of ideas appears out of his reason. They alone gave reason.”
—Ralph Waldo Emerson (1803–1882)
“The only rules comedy can tolerate are those of taste, and the only limitations those of libel.”
—James Thurber (1894–1961)