Can you use 2160p?

How to calculate your pixels per degree:
dist = your sitting distance from the screen
diag = your diagonal screen size

for 16:9 screens: Horizontal resolution x 0.02 x dist / diag
Or for some popular resolutions:
1280x720  = dist x 25.62 / diag
1366x768  = dist x 27.36 / diag
1920x1080 = dist x 38.45 / diag

for 5:4 screens: Horizontal resolution x 0.0224 x dist / diag
1280x1024 = dist x 28.61 / diag

For 4:3 screens: Horizontal resolution x 0.0218 x dist / diag
1600x1200 = dist x 34.91 / diag
2048x1536 = dist x 44.68 / diag

For 16:10 screens: Horizontal resolution x 0.0206 x dist / diag
1920x1200 = dist x 39.52 / diag

Example if you sit 8 ft away from a 40" 720p screen you see
96 x 25.62 / 40 = 61 pixels per degree in the center of the screen


What does this matter. The higher the pixels per degree you see the more real the picture gets. The current standard for HDTV is set at 60 ppd. That is what the well known chart for screen size and seating distance is based on.

http://www.blogcdn.com/www.engadget.com/media/2006/12/resolution_chart.jpg

The SMPTE HDTV standard further agrees with this number, advising an optimal field of view of 30 degrees. That corresponds to a seating distance of 1.63 x diagonal screen size, which equals 62.5 ppd in the center of the screen.

At 60 ppd you won't be able to see the individual pixel elements anymore. However studies done by NHK show that people perceive a big benefit going to 100 ppd, and can even perceive differences between picures upto 200 ppd. 200 ppd is considered to be the edge of human visual acuity. Beyond that you won't be able to tell if you're looking through a window or at a display screen.

Super Hi-vision or 8K video (8192x4320) is based on this research. Also known as UHDTV (7680x4320)

http://www.engadget.com/2012/07/31/super-hi-vision-eyes-on

http://www.dpreview.com/news/2012/08/01/8K-video-and-gigapan-images-bring-olympics-in-high-resolution


At 200 ppd UHDTV screen sizes aren't unreasonably big to fit in your home.


http://www.avsforum.com/t/1416475/viewing-distance-chart-720p-vs-1080p-vs-4k-vs-8k-and-beyond

At 8ft an UHDTV screen would be 73" diagonal. (dist x 0.769) By the time 8K arrives those screen sizes will be common. At that distance you will have a field of view of 37 degrees, still a little under the optimal field of view specified by THX requirements which is 40.04 degrees. (sitting at 1.2 * diagonal screen size)

You can see right now what super hi-vision or a reality display looks like. Simply walk away from your screen. You will see 200 ppd at (diag x 5.2) for 1080p sets, or (diag x 7.8) for 720p sets. For example a 40" 1080p set will give you 200 ppd at 17ft4" The iPad 4 retina display needs to be viewed at a distance of 43.4" to make it a true retina display.
Seems a bit far right? Maybe a bit overkill, but looking at test patterns from that distance shows 1 big advantage, no more aliasing problems, no more jaggies.


8k tests are being done now but it will be a long time before consumers see any of it. However 4K (4096x2160) and QFHD 2160p (3840x2160) are on the way. Actually they can't come soon enough. 1080p is a pretty low res for pc monitors considering how close you sit. No wonder 8xMSAA etc are considered a must in pc games.
Going upto 100 ppd makes a big difference. I see it daily going from the wide field of view of a 1080p projector to the much smaller field of view of a 1080p tv. Love the sharpness of the tv, love the wide field of view of the projector.  
4K is also what is used in cinema, and what 35mm film can provide. Unfortunately that also means 1 more round of upgrading your movie library.

The first 2160p displays are for sale now (ie if you happen to win the lottery)

http://www.trustedreviews.com/sony-vpl-vw1000es_Projector_review

At about $25,000

http://www.engadget.com/2012/07/19/lg-84-inch-ultra-definition-4k-hdtv/

At about $22,000

The first 4K movie is out too, for $299 shipped on a HDD.
http://reviews.cnet.com/8301-33199_7-57467138-221/first-4k-movie-available-for-sale/

It will probably be another 5 years before 2160p sets become affordable. The first plasma tvs also started at 15k or more back in 1997. Apart from the price there is also little content yet. (Except digital camera pictures. 2160p is 'only' 8.3mp which mobile phones can do already) Ofcourse if you can afford a 2160p set you can also a afford a pc capable of rendering at 3840x2160. Imagine a fully modded version of Skyrim running on that projector.

Anyone else looking forward to 2160p displays?

Some numbers:

1080p = 1920x1080
2160p = 3840x2160 QFHD (quad full high definition) or UHDTV1
4320p = 7680x4320 8K UHDTV or UHDTV2 (ultra high definition TV)

4K = 4096x2160 for consumer electronics
Digital cinema 4K = 4096x1714 (2.39:1) or 3996x2160 (1.85:1)
Academy 4K = 3656x2664 (1.37:1)
Full aperture 4K = 4096x3112 (1.32:1)
8K = 7680x4320 aka super hi-vision

Here are some pictures if you want to test your eyes or see the difference.
These work best on a ps3 or pc connected to a 1080p display with dot by dot, full, or pixel to pixel mode.
(The 360 unfortunately doesn't display 1080p images at full 1080p, some down and upscaling happens before the picture is shown)
It is probably easiest on a pc monitor as long as you display the pictures at the actual res.

Each picture is repeated, one at full res, one properly downscaled to a quarter res (2x2 pixels) and one at a third (3x3 pixels).
Now walk away as far as you need to, so you are sure you can't see any difference between the first and the second version of the picture.
Calculate the pixels per degree for that distance, half that value is the maximum your eyes can see. (for the display you are using)

Came in curious, saw math required, lost interest.

I got 79.86 for my bedroom. 52 inch 1080p, about 9 feet away from me.

I got 92.28 for my living room. 60 inch 1080p, about 12 feet away from me.

Nice thread.

I find myself sitting too close to the pc monitor at less then 2 feet at 34 ppd.
Living room at 104, 52" at little under 12 feet.
Projector at 58pp, 92" at little over 11 feet.

If I want the same sharpness on my pc monitor as on my tv I would need a horizontal resolution of 4009 pixels.
Too bad 4K monitors are not for sale yet
http://www.engadget.com/2012/06/05/viewsonic-vp3280-led-4k-monitor-hands-on/
Price estimated at: $30k - $40k

This will be the cheaper option for a while

Resolution is only part of the battle to reality displays.
The bigger the screen the more desirable higher frame rates get.
http://www.dpreview.com/news/2012/2/23/NHK-120fps-8k4k-sensor
Even beyond 120 fps will be useful, and not in the way that 240hz displays add intermediate frames. The problem is with motion blur. When you capture the image at 1/60th of a sec moving objects will be blurred. This is good to make the motion look more fluid, however the camera movement (or lack of) dictates what is blurred. Your eyes normally track objects that you're focussing on, keeping them without any motion blur.
A higher framerate will make the movement more fluid, moving objects will make smaller jumps. But it will only really help by also capturing the image at a faster shutter time. Otherwise you're just spreading the blur around.

Ironically games are best suited to the sort of interpolation that 240hz fluid motion displays do since you can disable all motion blur in games. However playing with a 3 frame delay (for the display to properly calculate the intermediate frames) isn't desirable. And any sort of frame rate dips or screen tearing will be greatly amplified.

Umm... 28 ppd for my PC monitor (21.5", 1080p)? Yeah, I'd like to but really can't put it farther away.

Well my bedroom TV is a 19" 720p at 16:9, and is about 7ft away (little annoyed I am having to do things in feet and inches for this, but nm) which works out at 94.3 ppd.
However no signal being sent to it has ever had higher than the DVD/Wii's 480p.

Not sure on your calculations in the OP svennoJ... you claim the calculation is: Horizontal resolution x 0.2 x dist / diag

But then your examples indicate you used 0.02 instead of 0.2

Or for some popular resolutions:
1280x720  = dist x 25.62 / diag
1366x768  = dist x 27.36 / diag
1920x1080 = dist x 38.45 / diag

Ah, hang on, the distance is probably supposed to be in the same measurment as the diagonal (my mistake) and the 0.2 was a mistake and meant to be 0.02.

Which gives my setup as 113.2 ppd... though as I only use a 480p signal I guess I game at 75.5 ppd

Thanks, I made a typo, it is 0.02. I corrected it.
And yes the units for distance and diagonal don't matter as long as they are the same.

Most games don't use 1080p, not even the full 720p. Anyway I was looking for the best case scenario, is there a reason to go beyond 1080p next gen or after. I think it will be worthwile as screens keep getting bigger to get a wider field of view.

HD remakes look so much more pleasant then wii games on big screens although they are not as graphically impressive. The extra resolution makes it a lot easier on the eyes. Playing Wii games at the SMPTE standard of 30 degrees field of view will give you 27.7 ppd at the center.

Well according the first graph, In my bedroom I would need to go above a 26" screen to notice any difference even for 720p over 480p... and as there seems to be a gap between 26" and 32" TVs nowadays I would have to buy a 32" TV just to have a decent picture improvement over standard definition (a TV that large would look ridiculous in my room)

Hell in our entire house there isn't really a suitable place to put a TV that would have a viewing distance over 10-12 feet, and I think anything above a 40" screen would look foolish for that distance anyway (current living room TV is 28" CRT beast that probably weighs as much as me) Which means 720p is really as high a resolution as is useful to me.

EDIT: The second graph seems to have a different conclusion though... the first seems to indicate that 10 feet away you can go up to 50" before you notice a benefit to 1080p, wheras the second indicates you would notice the benefit of 1080p as low as 15"

EDIT 2: Ok, now I read the OP properly I understand the difference... I have to admit though the supposed 30 degree viewing angle seems really large to me, I don't like watching TV at that size, I prefer to be able to see everything without having to look in different directions. (I think my bedroom angle is about 15 degrees at a guess, can't be bothered to do the math)

The first graph is a lower limit though, you will notice an improvement going to 100 ppd. The first graph is based on the older assumption of 60 ppd, which is enough not to see the individual pixels but doesn't mean a sharper image won't look better.

At 10 to 12 feet SMPTE standards suggest an upper limit of 74" to 88" diagonal 1080p tv at 62.5 ppd. At 720p you would only get 42 ppd.
At 60ppd you can go upto a 36" 720p tv in your bedroom, but if you want 480p to keep looking good your upper limit is about 24"

Going to a 30 degree viewing angle when you're used to 20 degrees (based on your numbers) is a big difference. It makes racing games a lot easier and everything else a lot more immersive. TVs get flatter and lighter all the time but if you don't have the wall space then there's little use for you. As for looking rediculous, you get used to it and then you don't want to go back.

Ofcourse 1080p is still largely useless unless you buy blu-rays or have your pc hooked up to the tv. 1080i broadcasts look sub dvd quality when things start moving and the highest bitrate for downloaded movies is 10mbps, streaming caps at 5mbps, 720p will be enough for another couple of years. And a 20 degree viewing angle is definitely the max you want to view the Wii at.