JVC ProHD GY-HD251 Specifications page 4

Advantages of ProHD
1. HDV format
format was defined by four companies: Canon Inc., Sharp
Corporation, Sony Corporation, and Victor Company of Japan
Limited (JVC). The specification of the HDV format incorporates
two versions, one progressive (720p) and the other interlaced
(1080i). HDV uses the same track pitch and tape speed as the
DV format, and therefore the recording times are the same
length as the DV format.
2. HD Progressive (720p/50) format for high
quality moving pictures and digital stills
Progressive scanning
JVC's ProHD products use the same
progressive scanning system used in high-
end HDTV cameras. Because the
GY-HD251 uses a full-frame (50p)
progressive scanning system, it has the
unique ability to capture and store full
frames of image information. An added
bonus of progressive scanning is that it is
a very simple process to convert a
progressive image to interlaced, but not
vice versa. When progressive recordings
are paused or played in slow motion, each
individual frame contains the full detail of
the original image — excellent for viewing
and analysing motion. Stills and prints
captured from HD progressive video look
far better than from interlaced video. In any
case, today's flat panel television displays and fixed matrix
projectors, such as D-ILA, DLP and LCD, are all native
progressive scanning systems. This means that JVC's
progressive HDV recordings can be displayed without
imperfection, because they do not need to pass through the
degenerative process of de-interlacing, prior to being
displayed.
HDV and DV compatibility
The HDV format uses the same recording track pitch (10 µm)
as Professional DV, meaning that ProHD also offers track pitch
compatibility with the DV format and the same recording time.
This remarkable HD recording capability was achieved by
developing a new high-power MPEG codec system capable of
maintaining high-definition picture quality, whilst compressing
the data to 19.7 Mbps bit rate. With its superior resolution and
advanced processing, ProHD delivers top performance in both
its native 16:9 HD mode and in the SD mode.
3●
HDV is a video format
designed to enable the
recording of high definition
MPEG-2 video on standard
DV media (DV or MiniDV
cassette tape). The HDV
Progressive HDV-compatible support
To maximise picture quality and performance from input to
output, JVC employs the HDV 720 progressive system.
Progressive HDV's resolution of 1280 x 720 is the same as the
native resolution of most HD display devices in use today
(LCD, plasma, DLP, D-ILA). HDV 720p is thus natively
compatible in terms of both resolution and scanning system
with the vast majority of today's HD displays.
3. Real 24p
24p Progressive Full HD images are ideal for cinematographic
applications. From shooting to editing and distribution, an HD
system can be established for film-like productions. Unlike 24p
images in standard definition, when real 24p HD video is
down-converted to SD, the result is truly film-like DVDs. The
camcorder itself, with its video lens removed and replaced by a
film lens converter system, such as the Mini 35 from P & S
Technik, effectively becomes a digital film camera.
4.JVC's dual recording system
The optional JVC Hard Disk Recorder DR-HD100 creates a
dual recording system of tape and hard disk. This system is
already utilised by Professional DV users the world over. The
many advantages inherent in JVC's dual recording system of
tape & hard disk drive are well appreciated. It was only natural
that JVC's range of ProHD models would include a Hard Disk
Drive recorder and one that can operate equally in DV and
HDV modes. The dual recording system provides fast and
efficient HDD-based editing and cost-effective archiving, using
low-cost tapes. Thanks to the newly developed MPEG-2
encoding IC, high-quality pictures can be recorded on readily
available compact DV cassettes, so running costs are minimal.
As no special equipment or exclusive media are required, the
operating costs of the total system can be kept low. The
DR-HD100 is mounted at the rear of the camcorder, utilising an
optional bracket which is provided by the leading battery
systems manufacturers.
The GY-HD251, fitted with
Mini 35 film adapter from P &
S Technik, becomes a digital
film camera.