I don't quite understand how
the shutter speed of a
video camera interacts with the frame rate. Since video records 29.97 frames
per second, what exactly happens when the shutter speed is faster than
30fps? I understand the effect in practice, how it looks on tape, but if
there are 29.97 frames recorded per second in video, what is happening when
my camera's shutter speed is set to 10,000fps? Are the 9,970 frames not
recorded during that second just thrown out? Thanks very much for your time
and expertise.
Cheers, Jacob Stone Seattle, WA
video camera interacts with the frame rate. Since video records 29.97 frames
per second, what exactly happens when the shutter speed is faster than
30fps? I understand the effect in practice, how it looks on tape, but if
there are 29.97 frames recorded per second in video, what is happening when
my camera's shutter speed is set to 10,000fps? Are the 9,970 frames not
recorded during that second just thrown out? Thanks very much for your time
and expertise.
Cheers, Jacob Stone Seattle, WA
A video signal is "interlaced" so is not strictly speaking a "frame"
like a
photographic frame. The signal is rapidly drawn across the lines, first
of
all across every other line, then again across the ones in between.
It
completes this process 29.97 times every second. So if you shoot
it at high
speed, what will happen is that the camera shutter will see only a
small
part of one frame because it is exposing each frame at 1/20000th of
a second
in your example above. So during this very short time, only a
small part of
the video picture will be drawn, so very little picture would appear
on each
final film frame, and of course as each frame is made, the part of
the
picture that is seen will vary making a very very large black roll
bar!