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Mtf Of Blu-ray/hd-dvds


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well, start one then.

Owen is correct in saying that 100% MTF is not attained between adjacent pixels in 1920x1080 Blu-ray or HD-DVDs of real life video. That result follows from Nyquist sampling theory. This result holds true even if the source material is from a very high resolution camera.

Alebonau is correct in saying that negatives can contain more than sufficient detail for 1920x1080 Blu-ray/Hd-DVDs. Of course, the zoom camera lens needs to be operating in a favourable part of its range, at a favourable aperture, and relevant parts of the scene need to lie within the depth of view with good lighting.

It can get bit more complicated when the negative was under or over exposed and the development of the print is adjusted to compensate.

Complications also arise with special effects.

Then there are decisions about editing. Films these days even if not filmed digitally may be edited digitally, ie. converted from negatives to digital and then back from digital to film.

To avoid any hint of digital artefacts, quite heavy softening may be applied in the digital processing.

I have a personal collection of about 6 HD-DVDs. In none of them is the resolution consistently high.

In one, King Kong, the computer animations appear to be at decidedly less than what the 1920x1080 format is capable of.

I could post in much greater detail but this will have to suffice for now.

Cheers,

MLXXX

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In one, King Kong, the computer animations appear to be at decidedly less than what the 1920x1080 format is capable of.

So what are you saying? Poor compression means it isn't 1920x1080?

This comment makes no sense to me.

The fact is HD DVD/Blu-ray are stored as 1920x1080. No more no less. just cause you don't like what is in those pixels doesn't make them disappear.

Here's some interesting comments from Josh Zyber (I'm sure you all know who he is)

If you really want to be padantic, The resolution of film, analogue video

and digital video are impossible to compare in any quanitifiable way

because they manifest themselves in inherently different ways and have to

be measured and quantified in very different ways.

Video sourced material on a DVD is much sharper than film originated

material. It cannot really be measured but it is a fact (and you have

agreed that that is the case). Film material projected onto a screen is

sharper than video originated material. Again, it can't be measured, but

it is true.

The original resolution of film can't be measured because it's a

photochemical process, not an electronic one. However, once transferred to

DVD, both film and video have the exact same resolution: 720x480 pixels

(or 720x576 for PAL).

Yes, but so what?

All DVDs have the same measurable resolution. Don't confuse resolution

with sharpness; they are not the same thing. As far as not being able to

compare the sharpness of two different sources, you could say the same

thing about any two productions photographed differently than one another,

regardless of format. Movie X can be sharper than Movie Y simply because

that's the way they were shot. Has nothing to do with film or video.

But it is an inherent feature of the digitalisation process that when you

move from the analogue domain to the digital domain, each pixel of the

digital domain gets its infomation from an correspondingly larger area of

the analogue source. Although the physical number of pixels is fixed, the

circle of confusion (to misuse an analogue term) is larger than one pixel

(and is totally dependant mainly on the source material, but also on how

good the conversion process is), thus diluting the real resolution.

Obviously a digital video source will retain its full resolution, but

although it would appear to be dependant on the very analogue lens system,

the MTF of the lens is more often than not, not the limiting factor (unless

you have a really cheap and nasty lens).

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There is no dispute the format is 1920x1080.

The topic is the Modulation Transfer Function at high spatial frequencies, which broadly translated means how clearly the 1920x1080 pixels succeed in portraying fine detail.

I'm afraid l'll have to look at the quote tomorrow. Sleep beckons ZZzzzz

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Owen is correct in saying that 100% MTF is not attained between adjacent pixels in 1920x1080 Blu-ray or HD-DVDs of real life video. That result follows from Nyquist sampling theory. This result holds true even if the source material is from a very high resolution camera.

Alebonau is correct in saying that negatives can contain more than sufficient detail for 1920x1080 Blu-ray/Hd-DVDs. Of course, the zoom camera lens needs to be operating in a favourable part of its range, at a favourable aperture, and relevant parts of the scene need to lie within the depth of view with good lighting.

It can get bit more complicated when the negative was under or over exposed and the development of the print is adjusted to compensate.

Complications also arise with special effects.

Then there are decisions about editing. Films these days even if not filmed digitally may be edited digitally, ie. converted from negatives to digital and then back from digital to film.

To avoid any hint of digital artefacts, quite heavy softening may be applied in the digital processing.

I have a personal collection of about 6 HD-DVDs. In none of them is the resolution consistently high.

In one, King Kong, the computer animations appear to be at decidedly less than what the 1920x1080 format is capable of.

I could post in much greater detail but this will have to suffice for now.

Cheers,

MLXXX

MLXX if you read my following links you will infact see that

- film more than capable of 6K using the prime lenses they do and 4K very easily utilising the lenses they use these days that are very good.

- Infact jsut check what the resolution capabilities of even a 35mm frame of a digital camera

- Additionally film scans are done at 4K lowry process for hi-def which is then down converted to 1920x1080

- The genesis camera is a 12mp one and with the lenses usesd is capable of a final output of 1920x1080, there are many films used to produce this for the hi-def eg apocalypto which received world wide aclaim for its PQ

-then there is CG material which is 1920x1080 there are no film or cameras involved here.

I am repeating the quotes here because they have been very obviously ignored, infact I'm quite sure people havent even bothered to read them, I'd like rebutal on every one of them thanks, and referenced proof in doing so that clearly indicated otherwise. eg. if you are saying the genesis camera with its 12.4mp 5760x2160 capability cant output 1920x1080 then i'd like to see properly referenced and specific proof it cant, not some verbious garbage saying otherwise..

some wiki links

wiki on genesis

http://en.wikipedia.org/wiki/Genesis_(Panavision)

Technical specs

The Genesis uses a 12.4 megapixel CCD chip, arranged in a 5760x2160 horizontally RGB filtered array. The vertical resolution is cut in half to 1080 by pixel binning, so the final output pixel resolution is 1920x1080, just slightly lower than a 2k film scan.

http://en.wikipedia.org/wiki/Digital_cinematography

wiki on image resolution of the formats

http://en.wikipedia.org/wiki/Image_resolution

DVDs encode 720 by 480 (NTSC) pixels or 720 by 576 (PAL) pixels

Blu-ray and HD DVD discs are typically encoded at 1920 by 1080 pixels

High definition television is 1920 by 1080 pixels or 1280 by 720 pixels

35 mm film is scanned for release on DVD at 1080 or 2000 lines as of 2005.

35 mm original camera negative motion picture film can resolve up to 6,000 lines.

35 mm projection positive motion picture film has about 2,000 lines which results from the analogue printing from the camera negative of an interpositive, and possibly an internegative, then a projection positive.

Sequences from newer films are scanned at 2,000, 4,000 or even 8,000 columns (line measured the other directions), called 2K, 4K and 8K, for quality visual effects editing on computers.

some other links...

How many pixels are there in even a 35mm frame of film

The very short answer is that there are around 20 million "quality" pixels in a top-quality 35mm shot. That's a shot with a tripod, mirror-up, with a top-rate lens and the finest-grained film, in decent light. 12 million are more typical for "good" shots. There may be as few as 4 million "quality" pixels in a handheld shot with a point-and-shoot camera or camera with a poor lens. And of course if focus is poor, or light is poor, or the camera was not held steady, the number will drop down below the 1-2 million pixels of the modern consumer digicam. Of course, one can have a bad shot with a digital camera too, not using all its resolving ability. However, few pick their gear with the plan of shooting badly.

http://pic.templetons.com/brad/photo/pixels.html

The maximum resoluton of film

Firstly, the film format, 35mm can accomodate 6K resolution. Secondly the quality of taking lens has a dramatic effect on resolution. While today's zoom lenses are extremely good, the ultimate quality can often only be achieved with prime lenses. Good prime lens can acheive a solid 4K on the film and still resolve some information at 6K.

http://www.cintel.co.uk/dlfiles/techdocs/E...0Resolution.pdf

the lowry film scan process

given the massive resolution possible with film the lowry process 4K process used for film transfers giving a horizontal pixel count of 4096 ! and down converted for hi-def of 1920x1080.

http://www.ezydvd.com.au/g/i/s/Videofuturelowryprocess.pdf

ps as an aside what I find by the way absolutely hilarious, is we have here the king of visual aquity, who pushes down everyones throat that we should sit with our noses to the screens to be able to resolve 1920x1080, infact now saying it is not possible at all to ever even get 1920x1080 onscreen ! :D:huh: . which is plain wrong as per all the links above, but anyways would explain why your misguided friend MLXXX, was infact doubt sitting at the wrong distance to the 57" telly he had so would have no hope of ever fully resolving 1920x1080, all the while preaching to every one the distance they should view their screens at :lol:

honestly I couldnt give a rats, the evidence is there and our misguided resolution nazi as far as I'm concerned, can view his MEGA telly at whatever distance he wants to and beleive as many pixels there are in the images he views as his darn little sorry hearts desire :P

anyways I'm away next few days, might pop in now and then..have fun me hearties :wub:

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I too may be pressed for time to contribute over the next few days, and have to go now.

However I'd provide this very interesting link: Blu-ray, HD-DVD & SD DVD Comparison Screenshots *WARNING - LARGE PICTURE FILES*

The first post contains a clip from the most recent King Kong movie. I have found the frame in my HD-DVD version of the movie, and it is no better resolution than what was captured for that first post.

It is fascinating to go through the various sample images and click on the icon that enables comparison of DVD vs the high definition version. But look carefully at the high definition version and you will often see that it is not as high resolution as it might be.

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Alebonau is correct in saying that negatives can contain more than sufficient detail for 1920x1080 Blu-ray/Hd-DVDs. Of course, the zoom camera lens needs to be operating in a favourable part of its range, at a favourable aperture, and relevant parts of the scene need to lie within the depth of view with good lighting.

It can get bit more complicated when the negative was under or over exposed and the development of the print is adjusted to compensate.

99% of lenses used during the production of a movie would be prime lenses not zoom as they have better optics.

It has been said that 35mm film has a native resolution of 4k and 16mm film around 1080p.

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99% of lenses used during the production of a movie would be prime lenses not zoom as they have better optics.

It has been said that 35mm film has a native resolution of 4k and 16mm film around 1080p.

Quite a substantial amount of "film" spends a fair amount of it's time in digital form during the editing and post-production process. At every stage in the content creation pathway there is a chance of loss of "information content" in the media, even if resolution is maintained. This depends entirely upon the tools, techniques and processes employed by the content creator. There are obviously cases where less than ideal processes are employed and information is lost, just as there are cases where it is obvious that this has not occurred.

Case by case arguments are much more likely to be accurate than sweeping generalisations based assumptions about processes that may or may not have been used.

It is impossible to get around the hard limits of information theory - but even within those constraints there is still a fair amount of leeway - whether or not that is financially viable with current film equipment in every shooting circumstance is very much in doubt.

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I too may be pressed for time to contribute over the next few days, and have to go now.

However I'd provide this very interesting link: Blu-ray, HD-DVD & SD DVD Comparison Screenshots *WARNING - LARGE PICTURE FILES*

The first post contains a clip from the most recent King Kong movie. I have found the frame in my HD-DVD version of the movie, and it is no better resolution than what was captured for that first post.

It is fascinating to go through the various sample images and click on the icon that enables comparison of DVD vs the high definition version. But look carefully at the high definition version and you will often see that it is not as high resolution as it might be.

mlxx those are screen shots, we are not talking display technology capability here. What we are talkig about is the ability of image capture systems be it film or digital or computer genrated that has greater than 1920x1080 for hd dvd and blu-ray as per my links above. if you are saying all the means for information feeding the creation of hd dvd and blu-ray is not capable of 1920x1080 I would like specific & referenced evidence to back that up. and do please read my links and info I provided specifically the link in regards the resolution of film, also please read re the capability of the genesis camera and what even is possible with a single 35mm frame of film let alone computer generated material.

99% of lenses used during the production of a movie would be prime lenses not zoom as they have better optics.

It has been said that 35mm film has a native resolution of 4k and 16mm film around 1080p.

that is quite correct as was said in my link above

http://www.cintel.co.uk/dlfiles/techdocs/E...0Resolution.pdf

The maximum resoluton of film

Firstly, the film format, 35mm can accomodate 6K resolution. Secondly the quality of taking lens has a dramatic effect on resolution. While today's zoom lenses are extremely good, the ultimate quality can often only be achieved with prime lenses. Good prime lens can acheive a solid 4K on the film and still resolve some information at 6K.

bris vegas would like some specific "case by case arguments :) with specific and referenced evidence. Keeping in mind that most of the movies we watch are produced by studios of massive resources, using technology of frightening capability we are not talking low budget art house productions here.

not sure if you had a look at the the wiki in regards genesis, here are movies for instance produced by it

http://en.wikipedia.org/wiki/Genesis_(Panavision)

Filmography

Feature films shot with Panavision Genesis are:

Apocalypto

Asterix in the Olympic Games

Balls Of Fury

Before The Devil Knows You're Dead

The Comebacks

Condemned

Click

Deja Vu

Fantastic Four: Rise of the Silver Surfer (limited portions)

The Ferryman

Flyboys

Grindhouse

His Majesty Minor

The Lookout

La Maison Du Bonheur

Next

The Other Boleyn Girl

Reign Over Me

Slipstream

Scary Movie IV

Superman Returns

A Tiger's Tale

Television series shot with the Panavision Genesis include Night Stalker, Conviction, What About Brian, Justice, and 3 Lbs..

Some television pilots shot with the Genesis include "Faceless", "In Case Of Emergency", "Brothers And Sisters", "52 Fights", and "Protege"..

additionally the genesis is not the only camera system used with this ability, the wiki lists quite a few other competitors to the genesis, that people might want to follow up and read up about and their capabilities via the links in wiki...

Panavision has many competitors. Several competitors have very similar features and some are already in wide use by the film industry.

Arriflex D-20 (35mm sensor size, 1080p output)

RED ONE (35mm sensor size, 4K output)

F-23 (Sony CineAlta) (2/3", 1080p)

Dalsa Origin (35mm, 4K)

GS Vitec noX (1.2", 2K)

Silicon Imaging SI-2K (16mm, 2K)

Thomson Viper FilmStream (2/3", 1080p)

Vision Research Phantom65 (65mm, 4K)

Vision Research PhantomHD (35mm, 2K)

Sony F23 (2/3", 1080p)

anyways really must run...

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Quite a substantial amount of "film" spends a fair amount of it's time in digital form during the editing and post-production process. At every stage in the content creation pathway there is a chance of loss of "information content" in the media, even if resolution is maintained. This depends entirely upon the tools, techniques and processes employed by the content creator. There are obviously cases where less than ideal processes are employed and information is lost, just as there are cases where it is obvious that this has not occurred.

Nearly every film that "Hollywood" makes this today uses digital intermediary in post production (the figure was 90% in 2006) that means that the film is scanned using a film scanner and the output is a sequence of high quality files, usually at 4k and commonly using targa. GFX live shots are then sent to effects labs (GFX occasionally is done at 2k and then up-converted back to 4K for integration). The edit is then done and again using the same resolution and files that were created from the original scan and also from the GFX production house. Once picture lock is completed the entire film is sent to colour graders, who colour correct, add grain and adjust sharpness all in digital. Lastly they use a "LUT" or look up table which allows them the proof between how the finished result will look when it recorded back to film. At this stage the film is complete and from here it is encoded to the different DVD, HD DVD, Bluray format, reformatted for 16:9 TV and most importantly sent to the film recorder for cinematic release.

In the digital domain nearly no resolution is lost from content creation right through to release.

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In the digital domain nearly no resolution is lost from content creation right through to release.

You have to distinguish between information and resolution. Like I said in my previous post, I don't want to make generalisations - but there are going to be cases where picture information is "lost" and in many cases - this is not a bad thing.

You even mentioned two cases yourself -

1) effects shots that are done at a lower resolution then upscaled (sure if they are done at 2k scaled to 4K then back down there should be minimal loss)

2) adding film grain - (I guess this depends on if you consider noise information or not ;) )

Going forward I expect to see pristine or very near pristine transfers, precisely because so much of the production pathway is digital (and because the encoding processes should become more familiar to studios etc.)

One of the big problem areas will be older, back catalog material - there are many classic films (and even some trash 80's ones) that I am looking forward to seeing again in HD. Transfers of this material is obviously going to have more issues associated with it.

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You have to distinguish between information and resolution. Like I said in my previous post, I don't want to make generalisations - but there are going to be cases where picture information is "lost" and in many cases - this is not a bad thing.

You even mentioned two cases yourself -

1) effects shots that are done at a lower resolution then upscaled (sure if they are done at 2k scaled to 4K then back down there should be minimal loss)

2) adding film grain - (I guess this depends on if you consider noise information or not ;) )

Going forward I expect to see pristine or very near pristine transfers, precisely because so much of the production pathway is digital (and because the encoding processes should become more familiar to studios etc.)

One of the big problem areas will be older, back catalog material - there are many classic films (and even some trash 80's ones) that I am looking forward to seeing again in HD. Transfers of this material is obviously going to have more issues associated with it.

its here already brisvegas, re back catalog material have a look at the new re-released bond films. dr no for instance produced many many years ago. have a look at the lowry 4k process used for film transfer on that. and in viewing even on dvd it is pristine, yet scanned to 4K they have specifically if you read their material done so for hd dvd and blu-ray and the results with that I'm sure when get released will be nothign less than amazing, cant wait to see my self. and there is much back catalog material being released on hi-def.

re grain not every movie has grain added, if lookign for pristine transfers there are absolutely pristine examples today, check out aeon flux on hd dvd, the departed or chronicles of riddic on hd dvd. and with the likes of the genesis camera not only is the "filming" digital but also entire production pathway being digital really the results speaks for them selves as it does on apocalypto on blu ray.

re effects shots on lower resolution and then upscaled, I'm sure htere'll be that kind of thing happening, as will there be not all productions that are not made to very highest of standards.

but the technology avaialble today to get 1920x1080 onto hd dvd and blu-ray is certainly able and very much being employed by the studios for tranfers to produce movies on the hi def hd dvd and blu ray formats of today.

now really really must run.

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mlxx those are screen shots, we are not talking display technology capability here.

Er no, they are electronic captures of the decoded picture data to be sent to the display; they are not photographs of displays. I did my own electronic capture to verify the frame from King Kong (which happened to be a key frame, so should have had optimal quality). My HTPC codec produced slightly different colour and contrast, but the softness of the frame was confirmed.

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Er no, they are electronic captures of the decoded picture data to be sent to the display; they are not photographs of displays. I did my own electronic capture to verify the frame from King Kong (which happened to be a key frame, so should have had optimal quality). My HTPC codec produced slightly different colour and contrast, but the softness of the frame was confirmed.

perhaps deficiencies in the HTPC hardware/software?

But I don't really see your point anyway. Are you hinging your entire case on your experience with King Kong that could be the result of any failing of your hardware or your eyesight?

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You have to distinguish between information and resolution. Like I said in my previous post, I don't want to make generalisations - but there are going to be cases where picture information is "lost" and in many cases - this is not a bad thing.

You even mentioned two cases yourself -

1) effects shots that are done at a lower resolution then upscaled (sure if they are done at 2k scaled to 4K then back down there should be minimal loss)

2) adding film grain - (I guess this depends on if you consider noise information or not ;) )

Going forward I expect to see pristine or very near pristine transfers, precisely because so much of the production pathway is digital (and because the encoding processes should become more familiar to studios etc.)

People whinge too much about grain. Certain movies look too clean when there is no grain, the grungy looks adds to the experience. Its an effect that when used properly works really well. Its been artificially added to films for over 10 years now. A movie shouldn't look like broadcast TV, it should look like a movie. Some people don't understand this.

"Pixel peeping" really pisses me off.

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Er no, they are electronic captures of the decoded picture data to be sent to the display; they are not photographs of displays. I did my own electronic capture to verify the frame from King Kong (which happened to be a key frame, so should have had optimal quality). My HTPC codec produced slightly different colour and contrast, but the softness of the frame was confirmed.

sorry still haven't seen anything from you to show current technology does not have the capabilty of capturing in excess of the requirements to ensure 1920x1080 for hd dvd or blu ray, all we've seen are some 'screenies'

neither have seen any specific evidence or material in rebuttal to all the links and info I have provided. mlx have you had a chance to read any of it ? to say any otherwise?

hosko some excellent postings from obviously someone with a good insight into film production & transfer process.

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I too may be pressed for time to contribute over the next few days, and have to go now.

However I'd provide this very interesting link: Blu-ray, HD-DVD & SD DVD Comparison Screenshots *WARNING - LARGE PICTURE FILES*

The first post contains a clip from the most recent King Kong movie. I have found the frame in my HD-DVD version of the movie, and it is no better resolution than what was captured for that first post.

It is fascinating to go through the various sample images and click on the icon that enables comparison of DVD vs the high definition version. But look carefully at the high definition version and you will often see that it is not as high resolution as it might be.

You do realize you lose resolution when you pause? Then you lose resolution when you capture. Then there is is the issue of whether the equipment fully resolved either image to start with. Also was any upscaling used on the DVD image? Stills can be a guide but do not provide the full "picture" (pardon the pun).

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hosko some excellent postings from obviously someone with a good insight into film production & transfer process.

A mate I went to college with operates the Northlight 2 4K scanner at animal logic. Most people really don't have a clue about the entire process. They still think that to get a movie onto a HD-DVD or Bluray that they use telecine. Each individual frame of 35mm gets scanned one at a time.

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sorry still haven't seen anything from you to show current technology does not have the capabilty of capturing in excess of the requirements to ensure 1920x1080 for hd dvd or blu ray

Ahhh... this is the problem... you are talking about individual, ideal cases i.e. right equipment / right process and whether or not it is possible (it is - and increasingly will be the standard).. whereas some other people are discussing the possibility of less than ideal situations where, in spite of it being possible to have 1920x1080 pixels of information, it doesn't actually happen.

I have read the Lowry documentation etc. and he talks about numerous examples where he only scans at 2k because the information simply wasn't in the negative to justify scanning at a higher res. So obviously in these cases you are not getting 1920x1080 pixels of information, even if you are getting that resolution.

I really don't care - just as long as it looks great. ;)

But I think the two different camps are arguing two different perspectives and purposefully ignoring what the other camp is trying to say.

Is it possible to have 1920x1080 pixels of real captured information represented faithfully on screen? - yes of course it is.

Does it happen in every HD transfer 100% of the time? - no it does not.

Should we care? - Yes- within reason, especially if we can identify where a studio has done a particularly poor job.

Would I like a 4k resolution projector to really examine the quality of a lowry scanned movie? - you bet! Anyone want to lend me one? ;)

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I have read the Lowry documentation etc. and he talks about numerous examples where he only scans at 2k because the information simply wasn't in the negative to justify scanning at a higher res. So obviously in these cases you are not getting 1920x1080 pixels of information, even if you are getting that resolution.

There is a massive difference between 4k to 2k, then 2k to 1080p is another massive step down, both steps are about the same as 1080p to 576p.

I think some people are confusing what 4k and 2k actually are. 4k refers to the amount of vertical resolution or it might make more sense if I put it this was 4096p, 2k then would equal 2048p. 2k has about 4 times the pixels of 1080p.

A pixel is a pixel you can call it resolution or information but in digital its all the same thing 1's and 0's

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Don't videos always have some degree of blurring? I mean if everything was resolved down to single pixels then it would look all aliased and pretty bad, like when you play video games without anti-aliasing - only much worse because the real world has more detail.

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You do realize you lose resolution when you pause? Then you lose resolution when you capture. Then there is is the issue of whether the equipment fully resolved either image to start with. Also was any upscaling used on the DVD image? Stills can be a guide but do not provide the full "picture" (pardon the pun).

Er, no. The capture of the HD-DVD on my system was not achieved by pausing, but in real time. The capture software grabbed the nearest key frame. This is as good as it gets.

By visual inspection, the picture resolution was no sharper on my 1920x1080 display whilst playing the hd-dvd video full screen as video, than when displaying the electronically grabbed still.

I don't think the argument is so much what might be theoretically achievable, as what is actually being achieved. I personally have been a bit disappointed at the softness of HD-DVDs I have seen.

I cannot comment on the DVD images in the AVS thread in any detail but yes obviously they would have needed to be upscaled to be shown side by side with high definition versions, as DVDs fall well short of the 1920x1080 format. Presumably the DVD images were derived from NTSC 720x480 format frames, though some may have been upscaled from PAL 720x576 format frames.

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There is a massive difference between 4k to 2k, then 2k to 1080p is another massive step down, both steps are about the same as 1080p to 576p.

I think some people are confusing what 4k and 2k actually are. 4k refers to the amount of vertical resolution or it might make more sense if I put it this was 4096p, 2k then would equal 2048p. 2k has about 4 times the pixels of 1080p.

A pixel is a pixel you can call it resolution or information but in digital its all the same thing 1's and 0's

This is where I have to dissagree - digital image is made up of pixels. These pixels are a "sample" of continuous real world information.

In our case we are talking about film - 35mm film in ideal circumstances (best optics, optimum exposure etc. etc) is estimated to have approx 4000 lines of information.

Nyquist–Shannon sampling theorem - http://en.wikipedia.org/wiki/Nyquist%E2%80...ampling_theorem

Exact reconstruction of a continuous-time baseband signal from its samples is possible if the signal is bandlimited and the sampling frequency is greater than twice the signal bandwidth.

images can for example - suffer from aliasing if the sampling resolution, or pixel density, is inadequate. For example, a digital photograph of a striped shirt with high frequencies (in other words, the distance between the stripes is small), can cause aliasing of the shirt when it is sampled by the camera's image sensor. The aliasing appears as a Moiré pattern. The "solution" to higher sampling in the spatial domain for this case would be to move closer to the shirt or use a higher resolution sensor.

The beauty of the lowry process is that it is scanning at 4k - hence fantastic ability to capture information available in the frame. Theoretically it should be scanned at 8k. Practically speaking, however, this is not required do to failings both of optics and film capture. Lowry himself talks about this in interviews.

As optics and capture technologies improve - higher than 4k may be called for in archival activities.

Lowry says that 4k was chosen because the amount of information available tops out at about 3k lines.

A pixel is a pixel you can call it resolution or information but in digital its all the same thing 1's and 0's

Not quite - say you have a situation where an image is captured of a scene that in the real world contains two, closely spaced, parallel lines. If you look closely enough in the real world you can clearly see that the lines are separated by white space. Now you capture an image of that scene, but because of a failure of optics to resolve the information - you end up with an image with two dark lines seperated not by a line of white pixels - but by grey ones.

These grey pixels may be real - they will have real world impacts on compression algorithms etc, but in relation to the original real world scene - they have no informational content.

Information theory is quite firm about this - I can take a 640x480 image and upscale in photoshop all the way to 4k and add no information, even though I have massively increased real resolution.

If the information was not captured in the original system - it doesn't matter what resolution you scan at - you can't recreate it.

This is why the multi-megapixel ccd in the genesis cameras are only half of the equation - you also need the good optics to be able to resolve details of the scene.

In summary I largely agree with you:

1) yes it is possible to have 1920 x1080 resolution images

2) it is possible to have 1920x1080 fully resolved pixels if the scan of the source material is of a suitably high resolution.

3) modern CCD and Optics are improving to the point where movies scenes can be captured at 4k eg. genesis cameras.

But if you think that this will be the case for every single piece of 35mm film ever shot, let alone 16mm, or material shot for television, archival footage, documentary footage, under/over exposed footage, or footage shot using sub par optics then you are kidding yourself.

I really don't think you are trying to argue the point above - but if you get so defensive when someone disagrees with you a little bit, that you start making generalisations and insisting on something that just can't be true - then you are going to start to look silly.

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But if you think that this will be the case for every single piece of 35mm film ever shot, let alone 16mm, or material shot for television, archival footage, documentary footage, under/over exposed footage, or footage shot using sub par optics then you are kidding yourself.

I specifically was talking about 35mm and the DI process the ultimately results in the master plate for cinematic release and Blu-ray and HD DVD and mostly been referring to modern film techniques. I never mentioned material shot for television, archival footage, documentary footage. I certainly wasn't talking since the creation of the film industry, that would just be ridiculous.

The company's that develop 35mm film for the big studio have it down to such a fine art there really is no under/over exposing these days. Since you talk of optics could you please tell me of a 35mm prime lens that is used in film production that can't resolve 4k, you may go back over the past 10 years to make it easier.

I really don't think you are trying to argue the point above - but if you get so defensive when someone disagrees with you a little bit, that you start making generalisations and insisting on something that just can't be true - then you are going to start to look silly.
I was originally arguing your point that there is loss of information in the post production of a modern movie. Great steps are put in place to make sure this doesn't happen. You may be misinterpreting my replys, debate shouldn't be seen as aggression it is simply stating ones position.
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I was originally arguing your point that there is loss of information in the post production of a modern movie. Great steps are put in place to make sure this doesn't happen. You may be misinterpreting my replys, debate shouldn't be seen as aggression it is simply stating ones position.

Sorry - I thought you were assuming that the work in post-pro ensured that all the information from the real physical scene was carried through the entire content creation pathway. My mistake.

As you say - great effort is taken to ensure resolution is not lost. There are isolated incidents where it is unavoidable - for instance:

- the DOP/Director decides they want to do it on purpose to achieve a certain effect.

- special effects would be too time/computationally intensive to render at 4k

- a shot was missed and footage needs to be cropped etc. in post production

etc.

Most of the time this really doesn't matter and anyway, it is the exception rather than the rule.

What I hate is when production companies rush a half baked transfer onto the market for commercial reasons and then expect folks to pay full price, only to turn around and "fix" it - and get us to shell out for it again. eg. recent rescan of blade runner.

This sort of problem was much more common in the DVD age - I am hoping that in the age of HD it will go away.

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What I hate is when production companies rush a half baked transfer onto the market for commercial reasons and then expect folks to pay full price, only to turn around and "fix" it - and get us to shell out for it again. eg. recent rescan of blade runner.

What are you talking about? Bladerunner has not been a double dip. It was originally release once on DVD 10 years ago. It has not been available since then. The new boxset is a complete re-do of everything. If you refer to the re-release of the directors cut about 6 months ago, this is the same print used in the new box set. When it was released it was made clear it was the same print, that a more elaborate boxset was coming and it was released at a bargain price. This was done as a treat for those who simply wanted it immediately and/or did not want the boxset. If you are referring to the DVD of 10 years ago then I think it is fair to say technology has advanced enough to warrent this "do-over". This is a bad example.

A better example would be the Fifth Element fiasco on blu-ray. While they claim they used the wrong transfer or some other BS, where was the quality control to pick this up. Original BD vs re-mastered BD pics can be found on AVS.

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must defintly enjoying your contributions to this thread both bris & hosko, with your techical inputs on the topic.

mo you are right re blade runner. the hidef version still to come, i'm anticipating eagerly.

re fifth element, the original release was using the wrong codec, though now re-released using same codec as hd dvd and a much better effort . really though there will always be stuff ups like that. this one embarrasing for blu ray. but shouldn't be used to hang the format or its capabilities.

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perhaps deficiencies in the HTPC hardware/software?

But I don't really see your point anyway. Are you hinging your entire case on your experience with King Kong that could be the result of any failing of your hardware or your eyesight?

I provided a link to an AVS thread showing many images. I indicated I had confirmed the accuracy of the image on the left of the first post. I suggest you look at the AVS thread. It has been there for some considerable time -- plenty of opportunity for videophiles to criticize the accuracy of the capture technique.

As for my own eyesight, it is better than 20/20 [6/6 in metric] and I routinely oberve good visible resolution in certain free to air 1920x1080 material such as House.

And some scenes of my HD-DVDs show much better resolution than that particular scene from King Kong.

I will address other points raised by yourself and others, after I've had a chance to go through the material; unless others have already addressed the issue.

And if anyone with a Blu-ray or Hd-DVD player wants to test their disk against the posts in the AVS thread they are welcome to do so and report whether their player yields a better picture.

By the way, one way of testing visible resolution is -- using good quality image processing software -- to downsample to half the size and then upsample back to the original size. If the processed image is almost the same as the original picture it suggests the original picture has low visible resolution (or conceivably that the original scene was of simple non-detailed objects). I use paint shop pro to digitally subtract similar photos, and then raise the gamma in the diference image to highlight where the dfferences are. A soft [e.g. out of focus] photo can yield virtually no differences when downrezzed to 960x540 and then uprezzed back to 1920x1080.

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I have been away and have not read the posts in this tread, so this is not in response to anyone.

I present this as a hopefully easy to understand explanation of the limitations in HD.

What is resolution?

Some may say it’s the number of pixels in an image; however that is not the case.

Resolution by definition means being able to resolve.

The visible resolution in an image is not directly related to the number of pixels. For example we can upscale a 720x576 image to 1920x1080. The resulting image has 1920x1080 pixels (pixel resolution) but can never have more then 720x576 visible resolution; as there was never more then 720x576 information to start with.

So, now that we have established that visible resolution can be much lower then the pixel resolution would indicate we can move on.

All film and video cameras are affected by a thing called Modulated Transfer Function or MTF for short. MTF describes the “Sharpness” or detail carrying ability of the device or capture system.

All parts of the chain from lens, film and film scanner or digital camera sensor (CCD), digital anti aliasing filters, video compression, video playback system and display all have an MTF. What we see on our TV screen is the sum of all the MTF losses in the chain.

Some people think if we point a digital camera at a scene, a single detail seen by the camera that is as small as a single pixel in the cameras CCD or sensor will be faithfully captured and sub sequentially displayed with pixel perfect precision on a display with the same number of pixels as the camera sensor. Unfortunately nothing could be further from the truth.

For a start all digital capture devices (camera and scanner sensors) are affected by Nyquist sampling limitations, which means the images produced have about half the visible resolution of the sensor.

For example, take a 1920x1080 video camera. The output of this camera will have no more then about 960x540 visible resolution (the Nyquist limited resolution or limit) due to the need to filter the output of the sensor above the Nyquist limit to avoid artifacts and aliasing in the output image.

To get an image of 1920x1080 visible resolution from a camera it must have a sensor with at least 3840x 2160 pixels. Even then, the image will have lost significant sharpness at 1920x1080 due to MTF losses in the lens and anti aliasing filter.

If you want to better understand Nyquist sampling theory I suggest you research on the site linked below.

Moving on, go to this site:

http://www.normankoren.com/Tutorials/MTF.html

Scroll down to the section titled “Image sharpness and detail”.

Look at the side of the page and you should see a picture with black and white vertical bars, this is a resolution test pattern used to test cameras.

At the top of the image you can see that the black and white bars are perfectly defined with dead sharp edges, all the way to the resolution limit at right. This is the original test image before it was photographed and is what some people expect the output of a high res digital camera to look like.

Now look at the sections further down and you can see the affect of MTF losses caused by the camera lens, film, film + lens and subsequent digitization and digital sharpening.

As you can see the final result has little resemblance to the original test pattern, and we have not introduced video compression losses yet.

Now I pose the question, what would you consider “fully resolved” resolution?

Obviously the “Original bands” at the top are “fully resolved” as they are perfect and have an MFT of 100% or 100% pixel to pixel contrast. If we go down to the “Film only” section we can see that although the image is heavily blurred we can just make out the smallest vertical bars at right. Since the bars are just visible with an MTF of about 10% this would still be classed as resolved, even though it is massively blurred compared to the original.

Film shot on a Panavison camera is generally acknowledged to have about 4k resolution, or 4 Mega pixels total, however at the upper limit of that 4k resolution all we get is barely perceptible detail with about 10 MTF, just like in the “Film only” example. Is this “fully resolved” not in my book its not, and I have no doubt others will agree.

Note. I only used the “Film only” example because it has resolution extending all the way to the right. The “Film + lens” result is too limited in res to illustrate my point.

If we look at the “Lens only” section, we can get some idea what an image with an MTF of about 50% looks like at the pixel resolution limit. This is the sort of results we might expect from digital 1920x1080 images derived from a Genesis digital cinema camera.

The linked .pdf white paper linked below provides interesting info on the REAL resolution of a Panavison cinema film camera. MTF graphs at are at the end of the document are in Lines per picture height, an expression used for both horizontal and vertical resolution. This is equivalent to pixel resolution that we are all accustomed to.

At a horizontal resolution of 1920, cinema film has an MTF of only 10% which is effectively nill, and represent virtually no visible detail.

Vertical resolution is better, with an MTF of about 57% at 1080, which is useable but not remotely close to fully resolved.

And download these. Copy and past URL into a new browser.

www.etconsult.com/papers/Technical%20Issues%20in%20Cinema%20Resolution.pdf

www.cst.fr/IMG/pdf/35mm_resolution_english.pdf

www.digitalpraxis.net/zippdf/scene-to-screen.pdf

These white papers provides more interesting info on the limitations of film as display in a typical cinema. Visible resolution is very ordinary and no where near 1920x1080.

More interesting info here confirming the limitations of film.

Be aware that graphs in cycles/mm need to be converted to lines per picture height to be comparable with resolution as we know it in the domestic environment.

For more interesting reading go here:

http://www.digitalpraxis.net/

Look at the left hand side of the page and select “Technical Papers”

Download DI Guide and Digital Film Scene to Screen .pdg files.

I cant find any useful MTF data on the Genesis digital cinema camera, but digital cameras of similar pixel count tend to behave in a similar manner.

There is the test data on the Canon EOS-1Ds Mark II 16 Mega pixel SLR, with 4992x3328 image sensor, very similar in sensor resolution to the Genesis digital cinema camera.

http://www.imaging-resource.com/PRODS/EOS1...1DS2IMATEST.HTM

MTF data at bottom of page.

Resolution at 50% MTF 1908x1630 without digital sharpening.

Resolution at 50% MTF 3084x2909 with digital image sharpening.

MTF at Nyquist limit (2496x1664) = 11 to 17% without image sharpening.

MTF at Nyquist limit (2496x1664) = 38% with image sharpening.

MTF at Nyquist limit (2496x1664) = 11 to 17% without image sharpening.

This camera, without artificial sharpening to boost its performance provides “Full HD” resolution (1920x1080) with only 50% MTF. Fine details with have only half the contrast they should have and cannot be considered “fully resolved”.

For comparison, here is an interesting and easy to comprehend article on the Sony 1080p 24 HD cameras

bssc.sel.sony.com/Professional/production/productsite/files/24PTechnicalSeminar2.pdf

The Sony 1920x1080p 24 HD camera with lens has an MTF at it’s Nyquist limit (960) of about 25%, about mid way between the unsharpened and sharpened results for the Canon EOS SLR at it’s Nyquist limit. This seems typical of digital cameras.

All the info I have provided confirms that 1920x1080 FULLY RESOLVED, is not a possibility at this point in time, even from the best available source.

The only way to get 1902x1080 resolution fully resolved, (with 100% MTF) is with computer generated graphics. Nothing shot with a digital or film camera can have 100% MTF at full HD resolution.

Resolution specifications without accompanying MTF data are worthless, so be very careful when resolution is quote. It’s the MTF rating that will tell you how sharp the image will look.

As pointed out in my links, digital video cameras tend to be sharper then film because that have better MTF in the very important mid resolution band, where the human eye is more sensitive. A typical 1920x1080 video camera looks very sharp yet has very limited resolution.

I hope this explains my stance on the limitations of HD. Sometime we get caught up in semantics over terminology, which clouds the real issues.

Regards to all.

Owen

Edited to correct inoperative links.

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however with most master these days coming from a minimum 2k the resolution in the master far exceeds that of "true HD" and hence is actually scaled down. The flaw with your argument is it seems based on the notion of upscaling and the belief that cameras capture less than "true HD" resolution. The reality is far more information is discarded than is kept when the final blu-ray or HD DVD is made.

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Don’t be like that, explain your case.

I said nothing about up scaling or 2k resolution.

I showed that the original film negative has very poor MTF at 1920x1080, about 10% horizontal and 57% vertical, not even close to fully resolved 1920x1080. 10% modulation isn’t worth a cracker.

Are you saying all the Panavision MTF data is inaccurate?

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however with most master these days coming from a minimum 2k the resolution in the master far exceeds that of "true HD" and hence is actually scaled down. The flaw with your argument is it seems based on the notion of upscaling and the belief that cameras capture less than "true HD" resolution. The reality is far more information is discarded than is kept when the final blu-ray or HD DVD is made.

exactly momaw, all the cameras I have provided info on have greater than 2k res. owen it really would be worth your while reading the links to info provided and also the very insightfull info provided by hosko who very clearly knows what he is talking about and a very clear understanding of the technological capabilties of film making & production.

it is without a shadow of doubt that the technology used to capture & transfer onto hd dvd & blu ray is more than capable of 1920x1080. all my links confirm this, hosko with his understanding has confirmed this too. not sure what more you would want.

to refute it is not possible to capture either by film or digital at more than 1920x1080, let alone to have cg material @ 1920x1080 on hd dvd & blu-ray is just a crazy argument.

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Don’t be like that, explain your case.

I said nothing about up scaling or 2k resolution.

I showed that the original film negative has very poor MTF at 1920x1080, about 10% horizontal and 57% vertical, not even close to fully resolved 1920x1080.

Are you saying all the Panavision MTF data is inaccurate?

Hence why I said:

The flaw with your argument is it seems based on the notion of upscaling and the belief that cameras capture less than "true HD" resolution.

The problem is film negative isn't 1920x1080 nor are these digital cameras recording such a low res.

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to refute it is not possible to capture either by film or digital at more than 1920x1080, let alone to have cg material @ 1920x1080 on hd dvd & blu-ray is just a crazy argument.

Cheeky devil ;) now you are just trying to stir.

Owen has specifically made neither of those points - suggesting he has is just mischevious. His argument is more nuanced than that..

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I never said that 1920x1080 or more was not attainable, what I have said is that the MTF or modulation at that sort of resolution is low and does not represent fully resolved,

all the MTF graphs I can find confirm this.

How can a pixel data that has less then half the pixel to pixel contrast of the original image be considered fully resolved?

You can have 4000x2000 pixels, but if they only have low MTF, there is little to be gained.

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Don’t be like that, explain your case.

I said nothing about up scaling or 2k resolution.

I showed that the original film negative has very poor MTF at 1920x1080, about 10% horizontal and 57% vertical, not even close to fully resolved 1920x1080. 10% modulation isn’t worth a cracker.

Are you saying all the Panavision MTF data is inaccurate?

we have seen nothing from you inregards the genesis camera or anyother camera which is easily able to do 2k and above.

we have nothing from you to refute any of the links i've provided. did you read the one about the resolution of film.

by the way normenkoren is just a guy into still consumer cameras. nothing to do with film cameras were talking here. we are also not talking about tv cameras.

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Hence why I said:

The problem is film negative isn't 1920x1080 nor are these digital cameras recording such a low res.

I just don't think he seems to be able to understand that, and has obviously read any of the info posted or linked to in this thread, just a pointless argument really now.

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I said I could not find any MTF data for a Genesis, but I did find data for a Canon SLR with similar pixel count.

I also said that most digital cameras seem quite similar in their MTF characteristics at the Nyquist limit, be they still or video.

The 16 Mega pixel (16k) Canon is good but it still cannot “fully resolve” 1920x1080, the MTF is no where near 100% at that resolution, no camera can do that.

Unless you can show at least one example of a cinema or video camera that can provide 100% MTF at 1920x1080 or more, I don’t see how you have a case.

More pixels dont count if they dont have usefull data.

I am not saying the Genesis is not good, it should have higher MTF and hence sharpness then anything else at the moment, but its far from perfect.

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I said I could not find any MTF data for a Genesis, but I did find data for a Canon SLR with similar pixel count.

I also said that most digital cameras seem quite similar in their MTF characteristics at the Nyquist limit, be they still or video.

The 16 Mega pixel (16k) Canon is good but it still cannot “fully resolve” 1920x1080, the MTF is no where near 100% at that resolution, no camera can do that.

Unless you can show at least one example of a cinema or video camera that can provide 100% MTF at 1920x1080 or more, I don’t see how you have a case.

More pixels dont count if they dont have usfull data.

I am not saying the Genesis is not good, it should have higher MTF and hence sharpness then anything else at the moment, but its far from perfect.

I think you are missing the point entirely that the recordings are not made at 1920x1080 but at a much higher resolution. Thus with a good compressionist the resultant image can be downscaled to a fully resolved 1920x1080 image. And this is precisely what they do.

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