Optimal Viewing distance

Which? have produced a viewing distance chart :
http://www.which.co.uk/technology/tv...y/?cmp=em-tech

which (sorry!) may be of interest!

Richard

Gawd, is there a how many times in a day should I pee guide soon as well?

Brian

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"Dickie Mint" wrote in message
...
Which? have produced a viewing distance chart :
http://www.which.co.uk/technology/tv...y/?cmp=em-tech
which (sorry!) may be of interest!

Richard

On 17/05/2011 17:49, Dickie Mint wrote:
Which? have produced a viewing distance chart :
http://www.which.co.uk/technology/tv...y/?cmp=em-tech

which (sorry!) may be of interest!

Richard
I have a 55" full LED TV on which I watch HD and SD. My viewing
distance is 3.3 Metres I'm very happy with the result, it's great viewing.
Your chart recommends 5 Metres. I think it's wrong.
Just my opinion.
Don

Donwill wrote:

I have a 55" full LED TV

What do you mean by "full LED"?

on which I watch HD and SD. My viewing distance is 3.3 Metres

I hope you don't watch 'Panorama', Jeremy Vine's head would be proper
scary at that size :-)

On 18/05/2011 08:04, Donwill wrote:
On 17/05/2011 17:49, Dickie Mint wrote:
Which? have produced a viewing distance chart :
http://www.which.co.uk/technology/tv...y/?cmp=em-tech

which (sorry!) may be of interest!

Richard
I have a 55" full LED TV on which I watch HD and SD. My viewing distance
is 3.3 Metres I'm very happy with the result, it's great viewing.
Your chart recommends 5 Metres. I think it's wrong.
Just my opinion.

Is your favourite channel CBeebies?

On May 17, 8:05*pm, Mike Henry
wrote:
In , Dickie Mint

wrote:
Which? have produced a viewing distance chart :
http://www.which.co.uk/technology/tv...t-size-tv-shou...

which (sorry!) may be of interest!

It is, thanks. On the face of it, it's a nice tool for most people to use..
But what values are behind the graphics - comparing the Which calculations
with the actual visual acuity chart athttp://www.blogcdn.com/hd.engadget.com/media/2006/12/resolution_chart...
(previously discussed here) it seems that if you select "HD" on the Which
site it gives you the TV size for the top of the 720p "full benefit of
720p visible" green line.

So I think they're implying that "HD" = "720p" :-(. It would have been
better to provide both 720p and 1080p options IMHO.

I think you're right Mike. In fact, I reckon they've just multiplied
the TV height (or diagonal) by some arbitrary value which is somewhere
between the "can just about see a difference" and "can see the full
benefit of".

I reckon they're using about 3H for HD, 4H for SD, and 3.25H for SD
+HD.
This implies needing a 25% larger TV when switching from SD to HD.
That's not right at all. Like-for-like, resolution-wise, if you sit in
the same place, you need a TV that's 2.6x larger (linear measure, not
area) to see the HD picture as clearly as you did an SD picture. In
reality, some people sit/sat too close to their SD TVs, and most sit
too far away from their HDTVs (or don't buy a large enough display).

FWIW the "1 pixel = 1 arcminute at the eye" calculation gives about:
1.8H for 1080p
2.7H for 720p
4.8H for decent SD
6.4H for lower res SD (~540 pixels wide, like many satellite
channels).

you can double those values (i.e. sit twice as far away) if you
believe the 1 pixel = 0.5 arcminute limit (i.e. believe perfect eyes
seeing one pixel with one sensor)...
3.6H for 1080p
5.4H for 720p
9.6H for decent SD
12.8H for lower res SD (~540 pixels wide, like many satellite
channels).

I think in reality the first list is the "if you sit any closer you
may start to see faults" one, and the second list is the "no one can
see the benefit this far away". Both ignore MPEG coding artefacts.

In the end, it's not being able to appreciate every pixel that matters
to most people - it's having a TV that looks in proportion with their
surroundings. I think the Which? guide might be about right with that,
though tastes change over time.

Cheers,
David.

On 18/05/2011 08:04, Donwill wrote:
I have a 55" full LED TV on which I watch HD and SD. My viewing distance
is 3.3 Metres I'm very happy with the result, it's great viewing.
Your chart recommends 5 Metres. I think it's wrong.
Just my opinion.
Don

I have a 40 inch unit, and sit a bit over 4M back.

I can see the MPEG artefacts caused by the excessively low bitrate on
some programme types. Although in theory I'd get a better view if I was
closer - not off these transmitters.

This is Freeview BTW; but I've often seen funny looking grass on Sky HD
in pubs when they have the ****** football on...

Andy

On 17/05/2011 17:49, Dickie Mint wrote:
Which? have produced a viewing distance chart :
http://www.which.co.uk/technology/tv...y/?cmp=em-tech

which (sorry!) may be of interest!

Richard

And I knew it was somewhere! Thanks to Keren at BBC R & D, and their
Librarian for digging out two R & D documents on viewing distance.
There are quotes in them to ITU & EBU reference documents too.

BBC R&D 1989/9

HDTV displays: subjective effects of scanning standards and domestic
picture sizes

http://www.bbc.co.uk/rd/publications..._1989_09.shtml

and

WHP 090

Results of a survey on television viewing distance

http://www.bbc.co.uk/rd/publications...paper090.shtml

Richard

On 18/05/2011 16:31, Silk wrote:
On 18/05/2011 08:04, Donwill wrote:
On 17/05/2011 17:49, Dickie Mint wrote:
Which? have produced a viewing distance chart :
http://www.which.co.uk/technology/tv...y/?cmp=em-tech


which (sorry!) may be of interest!

Richard
I have a 55" full LED TV on which I watch HD and SD. My viewing distance
is 3.3 Metres I'm very happy with the result, it's great viewing.
Your chart recommends 5 Metres. I think it's wrong.
Just my opinion.

Is your favourite channel CBeebies?
Sorry never heard of it. What is it?

On 18/05/2011 20:09, Andy Champ wrote:
On 18/05/2011 08:04, Donwill wrote:
I have a 55" full LED TV on which I watch HD and SD. My viewing distance
is 3.3 Metres I'm very happy with the result, it's great viewing.
Your chart recommends 5 Metres. I think it's wrong.
Just my opinion.
Don

I have a 40 inch unit, and sit a bit over 4M back.

I can see the MPEG artefacts caused by the excessively low bitrate on
some programme types. Although in theory I'd get a better view if I
was closer - not off these transmitters.

This is Freeview BTW; but I've often seen funny looking grass on Sky
HD in pubs when they have the ****** football on...

Andy
I watch on Freesat mainly, blu ray and another sat dish on which I get
Spanish progs to keep my ears tuned . I also get Sky news on that sat
but it's very poor quality..