1 The Director of Photography – an overview

Full Screen
“Silent”
Aperture
Figure 20.1 Full-screen 35 mm
‘Silent’ aperture
Academy
Aperture
Figure 20.2 The sound ‘Academy’
aperture
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Aspect ratios
The 35 mm frame
From the various originators of the motion picture camera came nearly
as many ideas as to how a piece of movie film should be laid out, what
the picture size should be and what type, if any, of perforations should
be deployed. In 1907, an international agreement was reached stating
that the film should be 35 mm wide, have a picture size of 0.980 in. �
0.735 in. and should have four perforations to each frame on both
sides of the frame. This format is now referred to as a full aperture or
as using an open gate. It is sometimes also referred to as the ‘Silent’
aperture. The layout of this format is shown in Figure 20.1.
It can only be imagined as to what negotiations were fought over to
come to an agreement where the dimension of the frame was in inches
(which both Britain and America use), the width of the film was measured
in millimetres (a continental concept) and all the parameters of the
perforation were totally American. Nevertheless, the standard was so
perfect we are still using it as the main plank of our technology today.
With the coming of the sound on film, space had to be found for the
optical soundtrack.The Society of Motion Picture Engineers of America
standardized the required layout as one keeping the same relationship
between the height and the width of the picture, but reducing the area by
24 per cent.As one side of the frame was to remain in the same place, this
would leave room on the other side for the new soundtrack, as shown
in Figure 20.2.This new picture size and placement is still known as the
‘Academy’ aperture and was formally standardized in February 1932.
As you can see in Figure 20.2, this had the added effect of widening
the spaces between the frames. This was wasteful, but did come with
one advantage – any need for mechanical joins could now be carried
out within this new area and, for the first time, would not show to the
audience.
The aspect ratio
Many different screen shapes have evolved since the adoption of the
Academy frame in 1932, but most have remained within the 35 mm
four-perforation pull-down format. In order to readily describe these
differing frames, we refer to them by their aspect ratio.The aspect ratio
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