First, thank you for posting the link to that document - very interesting information.

Another reason for 4k is 3D. I watched a 3D movie in a Sony-equipped 4k theater three weeks ago. The ads that ran before the movie all seemed to be in 2k, followed by a 4k ad for the Sony projection system used in the theater and some 4k trailers - very nice, the difference was noticeable.

But since the movie itself was in 3D, this was done by projecting 2k images separately for the left and right eye simultaneously, which is an improvement over the old 3D system.

ehm usually 3d movie are two 2k images for left and right, only at home, with passive screen you have half of resolution

You mean passive 3D TV? Idea of half of resolution is not true, image is combined by brain in very early stages, so you have full resulution. Difference can be noticeable for some hearly horizontal lines and some textures.

Btw bigges problem with theater and active TVs is not resolution, it is brightness. And normally it is too low.

When we're watching a movie in HDTV mode and usual distance, a small bird flying from lower left to upper centre flaps its way through a thousand pixels within and 10 frames in the half-second or so. Our eyes follow its smooth movement.

When we're sitting in a modern cinema, we need to turn our head to follow that bird. In 2K, we see each frame flicker. The illusion of movement is broken. In 4K, it's smoother.

Moore's law still applies. Higher res isn't going to go away - nor are higher frame rates.

Of course fps are more important. But 4K offers more positions for the bird to occupy. Spatial rez counts as well for smooth motion to a smaller degree.

I don't follow any logic here. Zero.

It's called antialiasing. A blocky bird-shape doesn't motion-blur over 24 pixels as well as it does over 48 pixels.

What Sony is talking about here is cinema seating design. Remember 20 years ago when you got to a Saturday matinee film late and had to sit in the cheap seats at the front? As a kid I'd crane my neck during the B&W serial as Batman juddered his way across the screen...

Well, all the seats are closer to the screen than we used to put up with. 2K projections work well for skin-tones and nature shots but show stepping with buildings and furniture.

An Aussie made a 35mm surfing film when DigiBeta came out. He got away with it by being careful with the horizon and any other straight lines.

Audiences have become discerning. If they have to pay for an evening out, they expect better than what they have at home.

You want to mix different things. Motion in 4K will be same

What did your last slave die of?;-)

What did your last slave die of?;-)

Where I live, that's what we say here to someone asks us to something a little over the top:

what did your last slave die of? (idiomatic, humorous) Used to indicate that someone is being bossy and/or demanding, usually to an unreasonable extent. http://en.wiktionary.org/wiki/what_did_your_last_slave_die_of

Now, to get real here, we're talking about being too close to screens. They say Digibeta's surfing movie pixels were 5cm across when projected: too big to be viewed close up but OK from a distance.

Everybody's had that experience of sitting very close to a screen (or even standing behind it) as images flicker across it. They can seem to jump a foot at a time. You can throw away the rule book about the illusion of motion when each 24th of a second of movement requires its own eye movement. You can forget about the illusion of a picture when the pixels are too big.

Now, I doubt if more resolution is going to fix that degree of stutter. But it's been my experience that higher resolution (as in a feature film) helped my eyes make more sense of it than the Ektachrome 64 trailers or newsreels we used to get before the feature.

And no, I don't think it's a big issue. It's off-topic regarding the need for 4K cinema screens.

And no, @Vitaliy_Kiselev, I wouldn't know where to start regarding scientific experiments about all this.

@mintcheerios

higher resolution made stutter more apparent because you have more pixels changing per frame making the change more apparent

I used to disagree with this idea - stuttering is often a shutter problem and slowing shutter speed or applying motion-blur fixes it.

But now (see 24P stutter thread) I get the feeling @Driftwood may be onto something re AVCHD's "tweening." And yes, if we are getting surprise i-frames contradicting the predictive frames - well, yes, theoretically the blurrier, lower-res the irregular frame is the better!

The best way to test the theory is to go to the movies. At present lots of the ads and pre-feature, locally produced stuff is likely to be shot in [AVCHD?] 2K. @Edwardm and @Mimirsan say these look different in 4K projection than the 4K source of the feature.

Which brings me to this quoted and actual resolution thingy:

it's more like 720p (and not even that)

There's resolution as in graininess and then there's resolution as in what's in a 1x1 pixel box. A movie cinema might help here, but it's still a good idea to zoom into a couple of stills to see what's going on: eg genuine 1080 individual pixels in a column, or clever interpolation of a mere 720, or usual anti-aliasing or plain old "too blurry to see"ness.

Mark's video is the type of comparison I'd like to see more often. Just you can't make a silk purse out of a sow's ear, neither can you create a flower-pattern on your bathroom floor with just 9 coloured tiles,nor can you display a slightly-off-horizontal straight line, a building horizon etc.

On the other hand, when you want to sell your camera, the best way to show off its capabilities is to demonstrate its rendition of skin-tones and nature, like the Bondi Beach Digibeta surfing success.

One thing we have learned is that viewers learn to appreciate higher resolutions and know the difference.

Kodak's tests with Vision 3 stocks show that the silver halide emulsion continues to resolve detail when digitized at 6K. Try and sell cinema audiences that 2K experience and they'll soon find their home cinema looks as good.

http://motion.kodak.com/motion/Hub/V3/index.htm

More interesting data regarding screen distances:

Notes:

1. Grey cells in the table indicate situations where pixels resolution is less than the limit of visual acuity. Limit of visual acuity is about 30 lp/degree.

2. Normal theatre places the front row about 1 picture height back from the screen.

3. “Best viewing” is normally 2 to 2.5 picture heights back from screen.

4. Anamorphic lens provides anisotropic pixel resolution in 1280 x 1024 mode – i.e. higher resolution vertically than horizontally.

5. Perceived resolution in an anisotropic situation is approximately the average of horizontal and vertical resolutions.

From this table, we can see that even a 4K projector does not satisfy the HVS requirement for simple limiting resolution until the viewer is almost 2 screen heights away from the screen.

Testing visual impression of resolution and contrast:

Contrast Sensitivity Function pattern showing that visual sensitivity to contrast is highest at lower resolutions than the threshold of acuity.

This is noted by the envelope of modulation that looks (sort of) like a Gaussian curve. If the pattern is observed from close up, the Gaussian shape moves right, if viewed from further away, it moves left. The peak on this curve represents the spatial frequency where contrast discrimination is most sensitive. (View from at least 5’ away on a 17” monitor with image at 150%)

From Matt Cowan 2002, Digital Cinema Resolution – Current Situation and Future Requirements (see PDF)

Note: This 2001 document also includes some outdated references to the resolution of film itself with respect to of a film media release print. This was produced with respect to a full film workflow, without digital intermediate, assuming degradation over multiple copy generations . Back then, film stocks were more grainy and cinema release digitization was only 2K.

The rest of the document is mostly applicable to today's screen sizes and viewer perception.

I saw Prometheus on a Sony 4K in 3D (optimal presentation setup, viewed "as intended" by the filmmakers), and it looked fabulous.

Where did you get that info? Just wondering.

Edit: checked IMDB, you're right. "2K Digital Intermediate"

http://www.imdb.com/title/tt1446714/technical

"2K Digital Intermediate"

I have found too many instances of IMDB using that exact phrase. I doubt it's always factual. In fact, IMDB's Technical Details section itself gets second-billing to the story and the stars. I'd like to know if there's any movie site anywhere near as comprehensive as IMDB but with better tech talk.