Lesson 3/Learning Event 2
Learning Event 2:
IDENTIFY THE TWO COMMON TYPES OF MECHANICAL SHUTTERS
1. The camera shutter is an adjustable mechanism that can be opened and
closed for a predetermined length of time to regulate the duration that
light is permitted to pass through the lens and expose the film. There are
two types or shutters commonly used. They are the focal plane shutter and
the between the lens (leaf type) shutter.
A focal plane shutter is a
curtain made of cloth or metal.
2. The selection if a shutter speed determines the slit width of the
curtain and the speed the lit travels across the film plane. Different slit
widths and different speeds of travel across the film plane provides several
different shutter speeds.
3. The focal plane shutter of modern 35mm cameras have two curtains.
A
slit of different widths is created by delaying the movement of the second
curtain in relation to the first (fig 3-1).
Figure 3-1.
Focal plane shutter
4. A between the lens shutter consists of thin metal blades activated by
springs. The selection of a shutter speed determines the duration of time
the blades are opened (fig 3-2).
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