Sony CCTV Systems - Manual (Page 8)

7
Time-lapse VCR technologies
Hybrid Recording (HSR-1P)
The Sony HSR-1P digital time-lapse recorder uses both a
hard disk drive (HDD) and a DV (digital video) tape drive
for storage. The image data is first recorded onto the
HDD and is then transferred to DV tape. This "hybrid"
approach to recording has two major advantages.
The first advantage is reduced maintenance. Because
the DV tape drive works only while recording the image
data being transferred from the HDD, the tape transport
and heads are stationary most of the time.
This significantly reduces the need for head
maintenance. The second advantage is multiple
protection. In the unlikely event that the DV tape drive
fails, recording continues onto the HDD. Conversely, if
the HDD fails, recording continues on the DV tape.
APC (Adaptive Picture Control)
As the recording heads of VCRs become worn after
extended use the picture quality will deteriorate unless
the recording current is adjusted accordingly. All Sony
SVT time-lapse VCRs have an APC (Adaptive Picture
Control) function which automatically detects the
condition of the recording head and the video cassette
tape, then sets the optimum record head current. With
conventional recorders the recording current is preset at
a constant level, which results in an excessive recording
signal as the VCR heads become worn. This is called
over-modulation. APC maintains the recording current at
the ideal level, preventing over-modulation and therefore
recording clear pictures even after long periods of use.
RealAction Recording (SVT-L230P)
The SVT-L230P time lapse VCR features RealAction high
density recording. For example, conventional time lapse
VCRs record only 5.5 fields per second in 24 hour
recording mode. However, Sony RealAction technology
allows recording of 16.6 fields per second - three times
as much information. This recording density ensures
smooth, natural recording of even fast moving objects.
Time
*1
*2
Recor
ding Curr
ent
*1
*2
(A)
Conventional VCR
Time
*1
*3
Recor
ding Curr
ent
*1
*3
VCR with APC
*1 Ideal recording current *1 Ideal recording current
*2 Preset recording current *3 APC recording current
(A) Excessive recording current
(over-modulation)
RealAction recording 16.6 fields/sec.
Normal time-lapse recording 5.5 fields/sec.
DV Tape Drive
Hard Disk Drive
DV Signal Transfer
<HSR-1 Recording Process>
Technologies - The Sony Advantage