How much of Blu-ray resolution do we actually use?

[saprano]

I know 2.35:1 films are 1920x816p= 1.5 mill+ pixels. But what about the rest of the ratios?

Is there a reason why they couldn't encode the full 1080p resolution into a 2.35 ratio?

I also think it sucks for people with CIH setups where they still get 800p resolution. Did nobody think of anamorphic BD's just like DVD's?


Discuss please.

[HDMe]

They would have to amend the spec to allow for other things... and player firmwares would probably have to be updated as well.

The HD spec calls for all HD broadcasts and Blu-ray to have a 1920x1080 image... for the 2.35:1 movies, they fill 200 lines or so vertically with blank space... for 4:3 movies you get blank space on the sides... but it is always a 1920x1080 image being transmitted.

This is different than the way DVDs were... since the anamorphic DVDs allowed for self-adjusting to 4:3 or 16x9 TVs.

Someone could do this for HD and Blu-rays... but I guess they just didn't think about people with projectors.

I agree, though, it would be cool if people with projectors could have full 1080 lines and then the equivalent additional horizontal resolution... but then that would mean more data on the disc... and either more compression to fit it or something since it would take more space than the current way they do it.

[lobosrul]

I still don't really get the reason anyone would buy a 21:9 TV. Why not just buy a 16:9 TV that is the same width, but taller? Unless you have some weird situation where the maximum TV size you can put in is limited by the height rather than the width, then maybe. You can get the same width 16:9 TV for much less money, and not have any (or very small) black bars on the huge amount of 16:9/1.85:1 content out there. And 4:3/1.37:1 sources won't look retarded.

If 2.4:1 movies were encoded anamorphically like you suggest, then displaying them on a 16:9 screen would require them to be scaled down (or the sides cropped) resulting in reduction in image quality, albeit probably a slight one.

Originally Posted by HDMe

They would have to amend the spec to allow for other things... and player firmwares would probably have to be updated as well.

The HD spec calls for all HD broadcasts and Blu-ray to have a 1920x1080 image... for the 2.35:1 movies, they fill 200 lines or so vertically with blank space... for 4:3 movies you get blank space on the sides... but it is always a 1920x1080 image being transmitted.

Actually BD spec does allow for 1440x1080. Although maybe only for anamorphic video (stretched to 16:9) and not for 4:3 video. Using that for old movies and TV shows would help out the very very few people out there still using 4:3 HDTV's.

[riverbelow]

When I move to projector it will be using a 16:9 screen, not CIH 2.35:1.

I just don't see justifying the price of anamorphic lens attachments and such, when the screen is going to be 80-100" wide already, I don't mind if the shape is not wide theater form - and if I despise projected black bars, I can invest in masking.

Movies like Jurassic Park, BTTF, Waterworld, Lion King, Avatar, Daylight - and split ratio like Dark Knight, Tron 3D ; will have the full image portrayed on the screen. I for one am cool with those movies being the "preference" of my collection as far as size grandeur, on the wall of my future projector setup!

The widescreen films are still gonna look impressive.

[Anthony P]

Originally Posted by saprano

I know 2.35:1 films are 1920x816p= 1.5 mill+ pixels. But what about the rest of the ratios?

Is there a reason why they couldn't encode the full 1080p resolution into a 2.35 ratio?

I also think it sucks for people with CIH setups where they still get 800p resolution. Did nobody think of anamorphic BD's just like DVD's?


Discuss please.

does it matter? For a true CIH it could make a difference, but I don't know many set-ups that are true CIH (i.e. I mean changeable lenses for 4:3, 16:9, 1.85 and 2.4 depending on source) in the end you are always sacrificing pixels one way or the other. If your display is 16:9 even if you had 1920x1080, you would lose some "resolution" if it is 4:3 or 2.4 or even 1.85 some vertically and other horizontally. If someone calls their setup CIH because they show at a 2.35 ratio they would lose resolution when watching something in 1.85,16:9 or 4:3 (and then there is Napoleon in 4.0).

[Anthony P]

I still don't really get the reason anyone would buy a 21:9 TV. Why not just buy a 16:9 TV that is the same width, but taller? Unless you have some weird situation where the maximum TV size you can put in is limited by the height rather than the width, then maybe. You can get the same width 16:9 TV for much less money, and not have any (or very small) black bars on the huge amount of 16:9/1.85:1 content out there. And 4:3/1.37:1 sources won't look retarded

for TV I agree, but it is different for projectors. for a TV height is not a big issue, but an 8' wide image in 16:9 means 4.5' tall image and it is not easy getting much taller. I don't have CIH set-up but I am pushing it with a 10' wide image because of height (which is ~5.5') but I could easily go wider since my room is just over 16' wide

[Deciazulado]

Originally Posted by HDMe

it would be cool if people with projectors could have full 1080 lines and then the equivalent additional horizontal resolution... but then that would mean more data on the disc... and either more compression to fit it or something since it would take more space than the current way they do it.

I guess one day that will be called Blu-ray 4K.. or something..




btw the anamorphic projection smpte standard became 2.39 four decades+ ago (more than 80% of the format's history) so any CIH screen I'd use would at least be that, I would assume the reason some BDs are being made in 2.35 is because A: gives slightly taller image, B: you get a superior image when cropping a 2K S-35 836 x 2000 pixel image to 818 x 1920 than scaling it 0.96x so it fits the 1920 width C: 40 years is nuthin', we need 400 more . When I've projected 35mm anamorphic prints, they are projected in 2.39

[HDMe]

Originally Posted by Deciazulado

I guess one day that will be called Blu-ray 4K.. or something..

Maybe... except that still won't "fix" the problem of a 2.35:1 ratio movie in a 4K capture still having less used vertical lines of resolution than a 1.78:1 movie given the way the 16x9 HD ratio has been defined.

Not saying *I* have a problem with it... just saying it would still be true.

[saprano]

I guess one day that will be called Blu-ray 4K.. or something.

Resolution will still be lost. I don't think that can be avoided. Can it? The only way to get higher resolution in the frame is to keep on increasing the resolution.

Bluray 1080p 2.35:1 movie = 1920x800p. 25% less resolution.

Bluray 2160p 2.35:1 movie = 3840x1890p. Assuming the same amout of lines are lost.

Correct me if im wrong.

[Deciazulado]

Originally Posted by saprano

Bluray 1080p 2.35:1 movie

Hopefully with 4K they will be 2.39 movies

(As I said above, the standard hasn't been 2.35 for 80% of the format's life)

Originally Posted by saprano

Resolution will still be lost. I don't think that can be avoided. Can it?

Super-35 for anamorphic extraction is 10.04mm x 24mm scanned at 4k (6µ pitch) that's 1672 x 4000 pixels

a S-35 negative resolving 70 c/mm is ~ 1400 x 3350 lines



Now, for anamorphic 35mm (used less and less as time goes by )

17.53mm x 20.96mm scanned 4k (6µ) that's 2922 x 3492 pixels

an anamorphic 35mm negative resolving 70 c/mm is ~ 2450 x 2900 lines



Then there's also higher K scanning (6K, 8K) and resizing down to 4K



So 4K letterboxed delivery of 'Scope' shaped movies at 1600 x 3800 ~ 1700 x 4000 pixels (depending on what flavor of K home delivery gets (I'm hoping of course for the Full 4K one) would kind of limit only the anamorphic 35mm's vertical resolution of 2450 lines to 1700 pixels (which according to one study is more than twice of what you see on an excellent theater's screen from normal 35mm projection) if home 4K doesn't become an anamorphic video format.

Remember that film resolution is a downward slope like the high frequency roll off of an audio tape beyond it's limits. So at around 2400 vertical lines is nearing 0 contrast (or film grain). Pixels can display higher contrast near their limit. Image clarity is composed of resolution x amplitude so being able to display 70% of the vertical resolution and 100% of the horizontal (overall, 83% of the total H x V ) but with better amplitude if needed, might offset this small 2 JNDs resolution trade off.

So I think this small loss of just 17% of the limiting resolution of an anamorphic 35 negative, which we have never actually seen (The closest would be if you shot 35mm anamorphic movies in Kodachrome positive film and could projected that single camera original on each and every screen. (Mmm Blu-ray 4K, Blu-ray Kodachrome? ).

Is not the end of the world, don't you think?

Besides, if you read comments about a recent shootout between IMAX sized film (~70mm across) printed and projected the regular N->IP->IN>P way vs a 11K scan (across the 70mm width) of it projected in 4K being more or less equivalent...




One more thing..


Put up this (click for the file) into your 1:1 pixel 16:9 display (or computer monitor). (with sharpness/enhancements set to 0 of course).

Make sure the pattern looks like this up close (1:1 pixel mode):
checkeredpattern-1.gif

It's an image ~ 800 pixels tall between the letterbox bars. Measure the checkerboard pattern's height on your display.

Now start moving back till you can't see the checkerboard pattern anymore (Image looks grey). Move in just the little bit enough so you can see it.
Write down the distance from your eyes to your monitor.

Divide this by the 800 pixel checkerboard pattern's height

You have the Picture Height distance limit for 800 pixels

Divide by two. You have the PH distance number for an image 1600 pixels tall (for example 'Scope" shaped movie in a 4K BD)

So now measure your normal sitting distance at home.

Divide your sitting distance by the 1600 PH distance number above and multiply that height by 2.39 for the width and you have the minimum V and H size of, for example a Scope CIH screen at home you'd need to have to see a 4K 2.39 image without missing details.



For BDs slice the screen dimensions in half.




__________________
ph-1-1.jpg

[RiseDarthVader]

Deciazulado do you have a test pattern like that for determining seating distance for full 1080p 16:9?