Sony XDCAM PDW-1500 - Manual (Page 37)

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3-4 Superimposed Text Information
a) Read errors will occur if the playback condition continues to deteriorate.
If a read error occurs, a “Disc Error!” alarm appears in the time data
display, the picture freezes, and audio is muted.
To display playback condition marks, set basic menu item
012 “CONDITION DISPLAY ON VIDEO MONITOR”
to “ena,” and set basic menu item 005 “DISPLAY
INFORMATION SELECT” to “T&sta.”
For details about operation, see 8-2-2 “Basic Menu
Operations” (page 95).
Playback condition displays
You can be alerted in advance to deteriorating playback
conditions and to error correction rates which are
approaching their limits.
Deteriorating playback may be due to the following
causes.
• Scratches and dust on the disc surface
This includes fingerprints, dust from the air, tar from
cigarette smoke, and so on.
Scratches and soiling which occur before recording are
not a problem because they are registered in advance as
defects, and recording avoids them. However, scratches
and soiling which occur after recording can lead to
deteriorating playback conditions.
• Aging of disc recording layers
Over several decades, the recording layers of optical
discs can age and cause deteriorating playback
conditions.
You can use this function to check archival discs and
other discs which have been stored for extended periods,
so that you can take action before the deterioration
progresses further.
• Deteriorating laser diodes performance
The performance of the laser diodes used in optical
heads can worsen with age, leading to deteriorating
playback conditions.
You can use the digital clock to check the total optical
output time of optical heads.
For details, see 9-1-1 “Digital Hours Meter” (page 122)
about this setting.
Refer to the Maintenance Manual for an approximate
guide to when it is time to replace optical heads.
To prevent playback conditions from
deteriorating
Pay attention to the following points when handling discs.
• Do not open disc cartridges and touch discs directly with
your hands.
• Do not store for long periods in locations which are
dusty or exposed to air circulated by fans.
• Do not store for long periods under high temperatures or
in locations exposed to direct sunlight.
If playback conditions have deteriorated
If a yellow or red playback condition mark appears, check
the following points.
Whether the disc displays the same playback condition
on other XDCAM devices: If so, the surface of the
disc may be dirty or scratched, or the performance of
the recording layers on the disc may have worsened
due to age. Do not use discs with these symptoms.
Whether every disc inserted into an XDCAM device
displays the same playback conditions: If so, the
performance of the laser diodes may have deteriorated.
Check the total optical output time.
Display Name Description
Green condition There is no problem with the
playback condition. This unit
and the disc can be used just
as they are. This
corresponds to the “green”
channel condition indicator of
a VTR.
Yellow condition The playback condition has
deteriorated to some degree.
There are no read errors, but
you should take the action
described in the next section.
This corresponds to the
“yellow” channel condition
indicator of a VTR.
Red condition The playback condition has
deteriorated. There are no
read errors,
a)
but you should
take the action described in
the next section. This
corresponds to the “red”
channel condition indicator of
a VTR.