54
Variable frame rate
This camera/VTR enables the frame rate (shooting
speed) to be set from 4 frames/sec. (3.99 Hz) to 60
frames/sec. (59.94 Hz).
Since the 720P/59.94 Hz format is used for recording
onto the tape or outputting to the HD SDI OUT
connector, users now have the exciting opportunity to
create a whole new dimension of moving images with
clearer slow-motion images and blur effects—a world
which was hitherto confined to the field of film
production—in their own video productions.
This unit automatically stores as the tape
management information both the frame rate
information which indicates the shooting speed and
the active frame information which indicates the first
frame where the frame image was switched in the
user’s bit of the sub-code track area (this used to be
the LTC area). This information is output from the TC
OUT connector and HD SDI OUT connector. Further,
the active frame information is stored in the least
significant digit of the user’s bit while the frame rate
information is stored in its lower third and fourth digits.
Setting the 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.
1White 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.
2Delayed 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 frames/sec.
(19.98 Hz) and below.
When the frame rate has been set to 20
frames/sec. (19.98 Hz) or below, it is recommended
that the unit be operated with the automatic
processing released.
3Black shading/white shading
Both black shading and white shading are
compensated for when the frame rate is set to 60
frames/sec. (59.94 Hz) and scan reverse is set to
OFF. No compensation is provided at any other
settings.
4Disturbed 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 frames/sec.
(23.98 Hz).
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 frames/sec. (23.98 Hz), 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.
1Perform the menu operations (pages 72 to 74),
and display the “FRAME MODE” screen.
2Turn the JOG dial button to move the arrow
(cursor) to the “FRAME RATE��� item.
3Press the JOG dial button, and set the desired
frame rate.
Turn the JOG dial button to select the frame rate,
and press the JOG dial button to enter the
selection.
4Press the MENU button to exit the menu
operations.
The setting menu is cleared, and the display
showing the unit’s current statuses appears at the
top and bottom of the viewfinder screen.
n< FRAME MODE >
FRAME RATE RANGE:60-12
FRAME RATE :24
SCAN REVERSE :OFF