Curved is the new flat
 

In article ,
Roderick Stewart wrote:

On Tue, 07 Jan 2014 18:51:42 +0000, Bill Wright
wrote:
This being so, sod's law dictates that sooner or later
somebody will install one of these monsters in exactly the right place
to catch the sun at exactly the time of day where the focus falls on
something that will make its owner regret the purchase in a big way.

Unlikely, because the curve is in the lateral plane only, so there is no
tight focal point.

Curved is the new flat
 

Zimmy wrote:

TV tech has been the emperors new clothes for quite some time, they'll
try anything to keep us buying new TVs.

In the early sixties the sale of new TV sets was slower than the
manufacturers would have liked. People had heard that BBC2 would need a
new set when it started, so they were making the old set last a bit
longer. Some of the manufacturers responded by fitting photocells on the
front of the sets. These controlled the brightness, so when you turned
the light on the picture brightened up. That was flop really, but then
sets started to appear that 'could be converted to 625'. Of course in
most cases this meant no more than that a extra hole had been drilled in
the cabinet and labelled '405/625'.

It was ever thus.

Bill

Curved is the new flat
 

Roger Wilmut wrote:

On Tue, 07 Jan 2014 18:51:42 +0000, Bill Wright
wrote:
This being so, sod's law dictates that sooner or later
.....


No I didn't. Had it been I, Mr Sod and his invaluable law would have
been given capitals.

Bill

Curved is the new flat
 

Roger Wilmut wrote:

Unlikely, because the curve is in the lateral plane only, so there is no
tight focal point.

I think the hypothesis is that even so a big screen would concentrate
the solar radiation enough for any part of the focal line to burn things.

Bill

Curved is the new flat
 

On Wed, 08 Jan 2014 09:03:51 +0000, Bill Wright
wrote:

One little thought. Wouldn't the optimum curve be one that presented
every part of the screen at right angles to the viewer's eye? (Note the
position of the apostrophe, which hints at a drawback!) If so, would the
curve also focus parallel rays? Not at the viewer position obviously,
but some other point along the a perpendicular projected out from the
centre of the screen?

You're describing a circle. For a small section of a circle, the focus
is at half the radius of curvature. The larger the section of a
circle, the more of the light rays don't go exactly through the focus,
which is why large concave reflectors that are supposed to focus
things are parabolic, but a concave mirror doesn't need optical
perfection to set things on fire. Try a shaving mirror, or anything
shiny and curved if it's big enough...

Rod.

Curved is the new flat
 

What if the curve is irregular and doesn't focus parallel rays?

I could be wrong, but I'm assuming the curvature will be fairly
uniform as that's the way cinema screens are curved,



******

Curved screens not sure that all are same.

The cinema I go to it is perfectly flat for modern digital films.

They have a very deep curved screen for the old Cinerama films of the 50's
also gets used for some 70mm process's but they not fit right, I think it
might be too deep a curve. Some films look better on the flat screen but
then lack size impact.

http://www.in70mm.com/pictureville/2...nday/index.htm

Scroll down to " Time to change from flat to curved screen"

Regards
David

Curved is the new flat
 

Just a thought but I recall using controls to reverse the pin-cushion effect
caused in CRT screens by the guns at roughly the centre of the screen having
to send the electron beam further to reach the corners.

Our distance from the extremes of the screen mean we experience the same
effect . If we are at the focus of a curved screen, we are (in theory)
roughly equidistant from the edges of screen. It worked in the huge 360
degree film shows displayed at Disneyland in the Bell Pavilion 30 years ago.

However to achieve something similar you would need a huge screen (by
domestic standards) or very tiny people. It may be clever but to me it is
the wrong application for clever technology.


__________________________________________________ _

Mageia 3 for x86_64, Kernel: 3.8.13.4 -desktop-1.mga3
KDE version 4.10.5 Running on an AMD 4-core processor

Curved is the new flat
 

On Wed, 08 Jan 2014 10:38:57 +0000, Bill Wright
wrote:

Roger Wilmut wrote:

Unlikely, because the curve is in the lateral plane only, so there is no
tight focal point.

I think the hypothesis is that even so a big screen would concentrate
the solar radiation enough for any part of the focal line to burn things.

That amount of direct sunlight will damage an OLED screen.
Apparently they don't like it up 'em.

Curved is the new flat
 

On Wed, 08 Jan 2014 16:44:05 +0000, lid wrote:


I think the hypothesis is that even so a big screen would concentrate
the solar radiation enough for any part of the focal line to burn things.

That amount of direct sunlight will damage an OLED screen.
Apparently they don't like it up 'em.

I wonder how many people know this?

Rod.

Curved is the new flat
 

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In article ,
Jim Lesurf wrote:

In article , David
wrote:


"Brian Gaff" wrote in message ...

So there we are then, we get rid of space hogging hurnier inducing
crts,
and go wafer thin flat screen. Now by all acounts we are going curved
screen. Why? What is the point?

There is little point with TVs. Cinema screens were flat, but with the
introduction of wide screens a slight curve was introduced to keep the
throw from the projector the same across the screen, thus minimising
brightness drop-off and distortion at the edges. Only with Cinerama and
Dimension 150 was the screen deep-curved to wrap round the audience and
involve them in the picture by filling their field of vision. Even IMAX
which aims at the same effect only curves the screen by enough to
equalize the throw across it.

With a TV is might look pretty for the person sitting dead centre, but
with a family watching it the people off-access are going to get more
distortion on the side of the screen they are off-axis on. It's a
gimmick.

but it's a gimmick that they want you to blow two grand on

The one I saw in John Lewis was a mere £6.5k.

Oh I don't doubt it

That's the early adopters price

getting down to 2 grand is the price where they start to expect "normal"
punters to start buying