🚀 go-pugleaf

In article <5edu0v$7ek$1...@news.wizvax.net>, Richard Shetron
<URL:mailto:mul...@wizvax.wizvax.net> wrote:
  
  [BIG SNIP]
  
There is some totally muddled thinking about exactly what is meant by
Beta.

The very first domestic video tape format was N1500 created by Philips
and used 3/4" tapes which ran for 60 mins maximum and produced lovely
pictures. A later N1700 version ran at half speed with double duration
and slightly reduced picture quality.

For a long time TV stations used to use N1500 to distribute viewing
copies of programmes created on 2" Quad format VCRs to broadcasters
contemplating purchase.

Round about the same time Sony introduced their U-Matic range which
were expensive, robust, mechanically wonderful machines using 3/4"
tape but because they used a "colour under" system and relatively low
tape writing density gave picture quality which was inferior to good
modern VHS. These machines have lasted for around 20 years and are
still in use in undemanding corporate, or off-line situations.

Meantime Sony introduced "Betamax" and the rest of the Japanese
industry introduced VHS, both domestic formats using 1/2" tape.  At
the time, and for some years forward Betamax gave a superior picture
to VHS and technically was a better integrated design.

With the spread of pre-recorded videos, the pressure of the market
place and unwillingness to support different tape libraries for esch
format meant the inevitable decline of Betamax.

Meantime Philips came along with Video 2000 which used 1/2" tape but,
like an audio cassette used both edges of the tape so that you
recorded 3 or 4 hours on one side and then turned the cassette over
and recorded another 3 or 4 hours back again on the other side.

Due to very innovative features in the design the performance of V2000
made both VHS and Betamax look very second best but, it was a case of
too little too late and V2000 quickly die the death. Incidentally I
still have an old Grundig V200 machine which will still outperform
VHS.

On the broadcast side VTRs advanced from the cumbersome 2" Quad system
to 1" "C", and in Europe "B" formats which became the standard for
both originating and broadcasting TV programmes for many years - and
which are still used today in some areas.

Around 18 years ago Sony introduced "Betacam" which was a component,
as distinct from composite format as all the machines mentioned above
had been. Component means that the Red, Green and Blue, signals coming
from the video cameras were encoded into a luminance section (which
had the black and white picture information) and a chrominance section
with the colour information which was time compressed by 50% and
incorporated the colour components in two sum and difference sections
(Normally known as Y U V, ie the complementary colours to R G & B).

Standard "Betacam" was confused by many people with "Betamax" as the
small, 30 minute, tape cassette loooked exactly like a "Betamax"
cassette. 

Betacam gave much better picture quality than U-Matic and rapidly took
over the higher end of the corporate video market although it was not
considered good enough for Broadcast work.

The next step was "Betacam SP" which used a higher specification metal
coated tape and rapidly took over from standard Betacam for more
demanding work and was used quite a lot for news and documentary
programmes by broadcasters.

In the interim U-Matic was improved by first "High Band U-Matic" which
used a more advanced picture quality which had some take up for local
broadcasting until it was crushed by the advance of Betacam SP.

Similarly S-VHS was a higher specification version of VHS with highly
s[ecified tape coatings and more sophisticated recording techniques. 
It also included a simplified component system Y - C (or S Video)
which was capable of much better quality than standard VHS, but still
not up to Betcam SP quality.

All these formats, plus the later 8mm and Hi 8 variants, which were a
more up to date and compact version of U-Matic and VHS techniques
relied on analogue recording so that there was a distinct loss in
quality in editing and copying. Even BetaSP begins to show image
degradation after abour 5 generations.

Panasonic introduced M2 which was virtually a copy of Beta SP and was
taken up by Thames TV who used it first for "The Bill" but it has now
virtually died out.

The next major step was D1 which was a professional 1" tape, entirely
digital, component system where multiple generations were no problem.
This was, and still is so horrendously expensive that it is only used
for big budget TV commercials.

Sony then introduced "Digital Betacam" which used the component system
but with everything compressed and recorded digitally so that over 100
generation copies showed very little image degradation. This is
prodably the most used system for both origination and transmission by
broadcasters at the moment.

More recently there have been D2 (a 3/4" analogue component broadcast
system still in use in some locations) D3 (A Panasonic 1/2" Analogue
component format which is used for playout by quite a number of
broadcast companies and D5 (a 1/2" Digital component system used by
Channel 4 amongst other broadcasters).

A couple of years ago the talk was that tape was finished and that
future systems would work digitally recording to disc.

Then in the last 15 months there have been a spate of new digital
systems both domestic and professional.

Most interesting is the new "DV" Format which is a standard accepted
world wide for recording on to 1/4" wide tape in a digital component
format. This is still too expensive to take over from VHS and Hi 8 but
it is coming.

The interesting thing is that it is possible to use the same tape
format and image quality as the domestic DV format and to produce
enhanced professional versions. In Sony's case they are promoting "DV
Cam" whilst Panasonic are offering "DVC-Pro". Both these systems can
accept tapes shot on domestic DV camcorders but by running the tapes
faster they give greater stability and allow features like timecode
and more robust control tracks to be incorporated.

DVC-Pro got off to s head start at the Atalanta Olympics where over
300 units were used in sports coverage.

Then to confuse things even further Sony have announced "Betacam SX"
which is a digital version of Betacam SP using the same tapestock, but
running at half speed and using quite a lot of compression of the
images. This gives picture quality almost as good as Digital Betacam
and is backward compatible with both standard Betacam and Betccam SP. 

Just to show that there is no ill feeling JVC have introduced "Digital
S" which is a digital version of S-VHS for professional use.

All these new systems have the fscility to download at faster than
realtime on to hard disc recorders for either on-line or off-line
editing.

Confused - you should be.  

Just imagine what it is like for a
professional organisation wanting to upgrade from Betacam SP and
wondering which horse to back. The only saving grace is that the
system used for origination and editing is now relatively unimportant
so long as the finished programme is delivered to the
broadcaster/publisher in the format they require for transmission which
with the low loss systems available today is no problem.

Sorry to go on at such length but I have been reading the various
postings and it was obvious that some posters were confused. Now you
all are.

Mike. 

-- 

    Mike Wilson       0113-253-3722       mi...@barc.demon.co.uk
Wakefield Acorn Computer Group but opinons expressed are mine alone
Hope to see you at the Wakefield Acorn Spring Show on May 17/18 97