# Re: Is 4:3 a dead Duck? for Viewing and ...

Discussion in 'NZ Computing' started by Lawrence D'Oliveiro, Feb 25, 2011.

1. ### Lawrence D'OliveiroGuest

In message <4d643a40\$>, Robert Cooze wrote:

> ... I am guessing FULL HD would be better there. but at what distance does
> it not matter?

According to this <http://www.clarkvision.com/articles/eye-resolution.html>,
the apparent distance between adjacent pixels should be 0.3 arc-minutes. Not
sure if that takes the Kell factor into account.

So at a viewing distance of 3 metres, this translates to a pixel spacing of
about 0.2mm. Which seems a bit small, since 1366 horizontal pixels (typical
for earlier 1080i-capable HD sets like mine) would only occupy a width of
about 36cm. My set is more like 3 times that size.

Lawrence D'Oliveiro, Feb 25, 2011

2. ### MeGuest

On 25/02/2011 3:12 p.m., Lawrence D'Oliveiro wrote:
> In message<4d643a40\$>, Robert Cooze wrote:
>
>> ... I am guessing FULL HD would be better there. but at what distance does
>> it not matter?

>
> According to this<http://www.clarkvision.com/articles/eye-resolution.html>,
> the apparent distance between adjacent pixels should be 0.3 arc-minutes. Not
> sure if that takes the Kell factor into account.
>
> So at a viewing distance of 3 metres, this translates to a pixel spacing of
> about 0.2mm. Which seems a bit small, since 1366 horizontal pixels (typical
> for earlier 1080i-capable HD sets like mine) would only occupy a width of
> about 36cm. My set is more like 3 times that size.
>

Try a little test for yourself. Draw and display (on a screen with 1:1
pixel mapping) and bitmap editor a black on white line pair with lines 1
pixel wide and 1 pixel apart. Then move back from the screen, and
you'll probably find that even with laptop screen typically about 1280
pixels wide, you can still probably see two lines at up to about 3
metres. That's not taking the "Kell Factor" into account - ie if that
line pair was not aligned with perfectly with pixels, then it's going to
show aliasing and/or resolution loss through interpolation.
Roger N Clark gets somewhat carried away at times. He posts (or used to
anyway) to rec.photo groups.

Me, Mar 5, 2011

3. ### RichardGuest

On 5/03/2011 4:17 p.m., Me wrote:

> Try a little test for yourself. Draw and display (on a screen with 1:1
> pixel mapping) and bitmap editor a black on white line pair with lines 1
> pixel wide and 1 pixel apart. Then move back from the screen, and you'll
> probably find that even with laptop screen typically about 1280 pixels
> wide, you can still probably see two lines at up to about 3 metres.
> That's not taking the "Kell Factor" into account - ie if that line pair
> was not aligned with perfectly with pixels, then it's going to show
> aliasing and/or resolution loss through interpolation.
> Roger N Clark gets somewhat carried away at times. He posts (or used to
> anyway) to rec.photo groups.

More importantly is when you are close to a low res panel you can see
the structure around the pixels like a screendoor over the image.

Richard, Mar 5, 2011