DVL-Digest 801 - Postings:
ADOBE SUPPORT SUCKS! re:After Effects 4.1 Production Bundle
DV and VITC : Repeat
DV to Film (DV at all?)
ADOBE SUPPORT SUCKS! re:After Effects 4.1 Production Bundle - "Perry"
From: Vizion Communication [mailto:firstname.lastname@example.org]
Sent: 20 March 2001 01:21
Subject: ADOBE SUPPORT SUCKS! re:After Effects 4.1 Production Bundle
DV and VITC : Repeat - "Perry"
Perhaps the following will indicate just how complicated timecode can
On broadcast tape formats, the timecode is written in SMPTE format, which
consists of a 40 byte code containing two separate time 'frames' in the form
HH:MM:SS:FF. The second 'frame' is called 'User Bits' but now often contains
a second time data locked to time of day. There are also a few housekeeping
bits, and the timecode data is of course progressed for each video frame.
On analog tape formats, the data is stored either on an audio track (usually
dedicated to timecode) called LTC or in the vertical blanking part of the
video where it is called VITC. There is nothing to stop you having
completely different numbers on either track (giving a total of 4 possible
sets of time data). On Digital video formats the data can also be stored in
the digital tape data, and some formats also retain the VITC video lines as
well as having an LTC track.
On the output of a deck, you can send analog (audio) timecode from a
dedicated port which on broadcast machines is usually balanced and on an XLR
type connector; on 'professional' machines it is often unbalanced on a BNC
connector. The timecode can often be (re)inserted as VITC on an analog video
output. It can also be made available on the RS-422 remote connector which
is usually fitted. On digital format machines fitted with SDI or SDTI, then
there is provision to send timecode on these interfaces.
I hope this may indicate that there is a vast number of possible
combinations, and there really is no such thing as THE timecode data for a
DV format (and DVCAM) has its own timecode format recorded in the data.
There is no dedicated audio timecode track and the VITC lines are stripped
off before recording so there can only be one set of data. The DV timecode
format is very similar to SMPTE and it is simple to translate between them.
What distinguishes the better professional decks from the consumer type is
not the recorded format, but the provisions to lock the internal timecode
generator to external references. DV data sent via Firewire has the inherent
timecode data, and many decks also support timecode via LANC. The studio
DVCAM decks also support the various forms of timecode as detailed earlier
for broadcast machines.
DV to Film (DV at all?) - "Perry"
The four pretty comparable wide screen cameras are:
Sony DSR-500 (DVCAM)
Ikegami HL-DV7 (DVCAM)
JVC GY-DV700 (DV)
Panasonic AJ-D610 (DVCPRO)
All are 2/3 inch with similar professional features and very comparable
performance for image quality. The differences are largely down to personal
choice since they do have their own characteristics, particularly with color
rendering. There are also differences in tape format and resultant maximum
record lengths for both the JVC and Panasonic of 1 hour.
There are some mechanical differences, and a huge wadge of prejudice from
most existing users who tend to swear by what they already know. There will
also be some large cost differences, but 'street' prices will vary wildly.
Be careful of exactly what is included and how much the essential 'extras'
cost. One manufacturer wanted over 1000UKP () for a tripod plate!
I have tested and reviewed all these cameras and would be very happy to use
any of them, although I've only used the Sony and JVC for real programmes.
In PAL the BBC have influenced both manufacturers, particularly for
colorimetry, and it is very difficult to split the two.
just my two penn'orth
(diese posts stammen von der DV-L Mailingliste - THX to Adam Wilt and Perry Mitchell :-)