Variable frame rate – Panasonic AJ-HDC27FP User Manual
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Variable frame rate
<Notes>
In this unit, the frame rate is set by changing the
storage time of the optical signals sensed by the CCD.
Depending on the frame rate setting, the following
problems may arise.
1
White streaks
The dark current of the photodiode that configures
the CCD’s pixels causes defective pixels to arise,
and this results in the appearance of white streaks
on the screen. This current increases in direct
proportion to the rise in the CCD’s temperature and
storage time in the photodiode.
In short, the white streaks increase in inverse
proportion to the frame rate setting.
When a lower frame rate setting is desired, reduce
the master gain setting and, where possible, avoid
direct sunlight and use the unit in a cool
environment.
2
Delayed response time in automatic processing
When the frame rate setting has been lowered, it
takes longer for the unit to perform the automatic
processing (such as auto white balance, flare
compensation, auto knee and auto iris), possibly
giving the user the impression that something is
odd or wrong.
The response time for automatic processes is
particularly slow at a frame rate of 20 fps and
below.
When the frame rate has been set to 20 fps or
below, it is recommended that the unit be operated
with the automatic processing released.
3
Disturbed images
The images may be disturbed for a moment if
scene-to-scene continuity is performed while the
time code is allowed to advance in the rec run
mode when the frame rate is set to 24 fps or 30 fps.
This occurs in order to reset the video signals from
the camera so as to maintain the continuity of the
time code recorded on the tape.
The disturbed images are not recorded on the tape
but they will affect the signals which are output from
the HD SDI OUT connector.
Furthermore, if the time code is allowed to advance
in the free run mode when the frame rate is set to
24 fps or 30 fps, at that instant when the time code
is preset or the time code is locked to the external
signal, the images may be disturbed for a moment.