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G0TEZ > TECH 20.03.10 19:34l 83 Lines 3997 Bytes #999 (0) @ WW
BID : 37612-GB7FCR
Read: GUEST
Subj: 3D TV & PCs ?
Path: IZ3LSV<IW0QNL<ON4HU<ON0BEL<GB7FCR
Sent: 100320/1621Z @:GB7FCR.#16.GBR.EU #:37612 [Blackpool] FBB-7.03a $:37612-GB
From: G0TEZ@GB7FCR.#16.GBR.EU
To : TECH@WW
We have had a lot of programmes on TV over the last year extolling the
forthcoming 3D TV and PCs.
We even had one film shown in the old red/green 3D with red & green
cardboard glasses for those who could get them. I was not impressed.
The two systems now at the prototype stage involve first: the simplest and
cheapest, is the polaroid system where one lens is vertically polarised
and one is horizontally polarised corresponding to the left and right eye
views respectively.
The third system, most complicated and requiring heavy, expensive glasses,
works on a frame sequential system whre the glasses ar switched from L to
R by a pused infra red beam received from the TV.
I have never seen the third system. I am sure it is fairly good but I have
my doubts. I saw the first two systems over 50 years ago' both came and
went. People didn't want to wear glasses, however cheap and the 3D effect
was rather artificial looking dependant on the size of the screen you were
watching.
One system which has been considered was the graticule system. It does go
under different names but, essentially, the screen was vertically
corrugasted. I nick named it the 'ploughed field' system.
I the case of cinema or TV one picture was sent to the left hand 'furrow'
while the other went to the right hand side. These could be viewed without
wearing any glasses, the only problem was that if you moved your head, you
mementarily saw both images with both eyes. In my view, this was not as
annoying as wearing glasses.
It was the system used by John Logie baird during WW II both for his
cinema projection system of TV and in his twin gun TV CRT. I never saw
that system but people I have spoken to said that the large screen (25")
full colour, 3D system was pretty good as was the cinema system. Why we
adopted TV screens as small as 9" in B&W after the war, remains a mystery
?
I do have clear memories of the photographic graticule system around 1953.
These pics were usually sold as postcards and the 3D effect was quite
good.
There was a variation of this trick on some cards sold in 1953 for the
coronation of our queen, If you looked at the card from one angle, you saw
the Queen, Tilt it slightly and it magically became a picture of the Duke
of Edinburgh. I suspect that they never caught on because of price, We
were a poor nation after WW II and even normal colour photos were out of
most people's price range, let alone 3D. I still have a couple of colour
snaps I took in 1962 but colour ohotography did not become commonplace
until about 1969. Perhaps this was the reason for adopting small screen,
mono TV until 1967 when we finally settled on PAL CTV with the patented
RCA shadow mask CRT which meant that our manufacturers had to pay
royalties to RCA for every TV they made. The RCA shadowmask also cut down
the light emitted by the CRT by around 60%. The nearest we got to a twin
or three gun CRT was the 'PIL' tube used in the Sony Trinitron but the
shadow mask still remained though it was brighter than the RCA version.
I do wonder about compatibility with the 3D systems. I expect they will Tx
just one view only for those who don't want or can't afford 3D.
I, for one, don't fancy sitting watching TV with glasses on - and what
happens to people who wear normal glasses ? Will they have to sit wearing
two pairs of glasses, one atop the other ?
I wonder what experiences people in other countries have had with the old
attempts at 3D, most packet users are as old or older than me and, despite
not having had a coronation to remember, have probably seen the red/green,
polaroid and graticule versions of film and photo.
It looks as though we are going to get it but I see a battle like the one
between VHS and Betamax and the more recent DVD formats, coming our way.
73 - Ian, G0TEZ
Msg timed: 16:20 GMT on 2010-Mar-20
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