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Delivering 8K VFX Shots For the Dark Knight
agent4256 writes "Barbara Robertson over at Studio Daily put forth this article featuring the technical background for the production of The Dark Knight. With most of the film shot with IMAX cameras (producing a theoretical resolution of 18k), the studios could not handle the size. Instead, they cut the resolution by more than half, down to 8K, the maximum resolution for scanned film. 'A single 8K frame requires 200 MB of data,' Franklin says. 'So we had to upgrade our whole infrastructure. We needed faster network speeds to move data around, massively beefed up servers, and — the most important thing — a new compositing solution.' To give you an idea of how far technology has taken us: 'In 1999, when we worked on Pitch Black [released in 2000], we needed to access 2 TB of data,' Franklin says. 'This show used over 100 TB of data.'"
K = thousand, and they're referring to lines of resolution.
For comparison, 1080p HDTV has 1080 lines of resolution. That IMAX camera records around 18,000 lines.
The 'k' refers to the horizontal resolution. The vertical resolution is a given since the aspect ratio is a fixed 1.34:1.
18K means a 18000 x 13433 resolution frame.
You forgot a few zeros... 100 000 000 MB / 200MB = 500 000
Your math is a 1000 out. 100TB ~= 100,000,000MB / 200MB = 500,000 frames for the movie, which does sound about right.
Note that the poster that you replied to already said kilo, and I'm pretty sure every person on this website knows what the prefix for thousand is. What we want to know is what the K is specifically, there are eighteen-thousand _______ per frame, and we want to know what the _______ is.
For comparison, 1080p HDTV has 1080 lines of resolution.
Actually, 1080p has 1920 lines of horizontal resolution (just under 2K, which is 2048).
This guy's the limit!
Don't you wish slashdot had an edit feature? Clearly I meant 4.5 *gigabytes* per second.....
1080p is roughly 2K, because that refers to the horizontal resolution: 1080p is 1920 pixels wide. That's right. Most digital cinemas don't deliver a higher resolution than a 1080p home cinema. 4K projectors are not yet widely deployed. Regarding the initial question: 18K with an aspect ratio of 2:1 is 162 megapixels. 8k is 32 megapixels. 16bit per channel is 6 bytes per pixel: 32 megapixels * 6bytes/pixel = 192 megabytes.
Every element of a composite counts separately. At minimum, you're talking about a guy in front of a greenscreen and a background plate, which takes up twice the space of the background plate alone.
Make me a friend and I'll mod you up
...but only about 25 - 30% of the film was shot in IMAX, at four times the cost of regular the anamorphic process used for the rest of the film.
Digital is dead! Long live film!
You have to look at the diagram in the wikipedia article you linked. The terms 2K and 4K as used in the visual effects industry refer to frame width. 2K is 2048 wide and 4K is 4096 wide.
It is different than the terms used for HDTV, where 1080p means 1080 vertical.
(I've worked in a VFX shop)
Which is only 5.8 hours of film, assuming 24 frames per second. That would definitely fit the entire movie, but it would be nowhere close to all the footage that was shot. It's not like all movies are filmed like Russian Ark.
Anthropic principle: We see the universe the way it is because if it were different we would not be here to see it.
Anyone thinking Batman has a simplistic right-wing message is naive or hasn't seen the movie. The message is pretty complicated, and there's been a lot of discussion about this in blogs this week.
One of the better analysis, and some discussion which references the comic books:
http://www.cogitamusblog.com/2008/07/the-dark-night.html
The reference you quote does make it clear, but you've drawn the wrong conclusion:
> 5.6K: 5616x4096; A full 5.6K was actually...
> 8K: 8192x6144; approximately ....
Thus 8K is 8192 pixels wide (not lines per frame) and 6144 pixels high. We commonly also use 2K's (2048 x 1501), 4K's (4096 x 3002), etc.
Also note that the digital professional cinema (not HDTV) industry (the world of DCI) also always uses image width rather than height to define resolutions (2K = 2048 x 1080, 4K = 4096 x 2160).
[/me = Technical Director on several digital 3D Imax films back through the late '90's -- these Hollywood guys are just now discovering stuff the rest of us have known for ages]
No. Well...maybe. Actually, yes. It really just depends.
No, GP had it right. "2K" is ~2048x1080, with some variance. With 1080 horizontal lines, and approximately 2000 (2k) horizontal pixels.
http://en.wikipedia.org/wiki/Image:Vector_Video_Standards2.svg
http://www.dcinematoday.com/dc/features.aspx?ID=16
http://campustechnology.com/articles/45435/
-A single 8K frame requires 200 MB of data.
-The Dark Knight is officially listed at 2hrs 30 minutes (150 minutes= 9000seconds)
-Total usage 100 TB (5 frames a Gig, 5120 per T, 512,000+ frames)
Minimal frame rate is ~24/s.
200 MB/frame x 9,000 sec/movie x 24 frames/second = 43200000 MB=42187.5 GB = 41.2 TB.
If the frame rate was 60 frames/second then that would be the whole film (no retakes, extras, bloopers etc).
I never realized the sheer amount of compression that is going on between the raw footage and getting it into a DVD.
Many people have corrected your GB v. TB, mistake but as someone who works on the tech side of a major VFX house, your $150/TB estimate is way off.
When a few thousand processors all need to load the same file simultaneously, a Western Digital from newegg does not cut it. :)
2k, 4k and 8k, when referred to film, are the horizontal resolution.
720p and 1080p when referred to TV sizes, refer to the vertical resolution.
Look at the image in the middle with the coloured blocks
http://en.wikipedia.org/wiki/Digital_cinematography [wikipedia.org]
It shows 2K being just slightly larger than 1080p. If 2k referred to the vertical size then it would cover 4 times the area
Actually, 8K _does_ refer to the horizontal resolution when you are talking about film scanning.
http://en.wikipedia.org/wiki/Motion_picture_film_scanner
We at the StereoLab in the National Film Board of Canada have an infrastructure set up specifically to manage a number of simultaneous 3D productions, several in "Large Format" (i.e. Imax) resolutions and the rest in various HD and 35mm formats. It's been to make over a dozen 3D digital films in the last few years or so.
In practice we use about an equal mix of internal data server drives, SAN, NAS, and a pool of bare drives with a stack of empty shells. Often people drop a drive in a shell and attach it (via eSATA, FW800 or USB in that order of preference) to whatever machine they need it on, because it reduces network load. This technique works especially well for intermediate data that is output, reinput, and then discarded.
No. Well...maybe. Actually, yes. It really just depends.
1080p has 1080 horizontal lines of resolution and 1920 vertical columns of resolution. Whether the 18,000 they are referring to are lines or columns, I'm not sure, because the only resolution data I can find on IMAX is 10,000 columns by 7,000 lines. Although that is just an "equivalency" as it's all recorded onto analog film which doesn't have "pixels" or "lines" or "columns", per se. It's only when you scan it (and thus the quality of your scanner I would assume) that digital measurements really start to become relevant.
Either way, IMAX resolution FTW.
Some IMAX is 48 fps. 3D IMAX can be 96 fps.
For reference, the vast majority of digital projectors in existence are 2K. There are a few 4K ones in the wild, but the most popular tech for electronic projection (namely DLP) currently maxes out at 2K. Sony has some 4K SXRD projectors available, but very few theaters have installed them.
The IMAX company is currently still running most of their theaters on the 15-perf 70mm film systems, so you can still see the full 8K image to day if you want to. The problem is, they are planning to install DLP-based systems that will reduce the resolution to 2K x 2K (although the article doesn't mention that). Once those are installed, you will not be able to see images like we're seeing today. The resolution will be far lower.
Even if Nolan and his team go for these kinds of high resolution images again for the next movie, there might not be any place to see it that can do it justice.
Now I know someone is going to chime in and say that film is analog, so anything digital is automatically better, but ask yourself: Would you replace a high quality analog sound system with 4-bit digital sound? That's approximately what we're talking about here. If the IMAX company were planning to tile a bunch of 2K x 2K images on the screen to produce an 8K image, or maybe use some other technology to achieve the kind of resolution they have today, then it would be a different story. But they aren't.
See it now, before they take it away.
Free Hans!
Film has a resolution, even though it isn't in the form of nice sharp-edged pixels. It's a question of how close together two objects can be and still be distinguished -- the distance is called the circle of confusion, within which the two objects are not fully distinct. Lenses, film, and printing process all play a role in the resolution of the final product. For test work, one usually uses a printed image with a very fine array of slowly converging lines, and you look for how close together the lines can get before they become indistinct. As a result, the number of (distinguishable) lines you can fit on the film is the natural way to measure its resolution. So film really does have "lines" and though they're not quite the same as in a digital system, they're remarkably close.
(Be aware there's a factor of two in there for Nyquist; a 1000 pixel wide display can only show 500 lines, obviously, and the same effect applies to analog systems.)
Of course, with better digital sensors (ie lots of megapixels), the lens quality becomes the limiting factor, and it would again make sense to speak of the imaging system in terms of lines of resolution rather than megapixels. There's a reason cheap cell phone cameras don't produce as sharp an image as a real camera with a good lens; if you want to measure the quality of the entire imaging system, you end up back with old-fashioned analog lines of resolution as one of the fundamental metrics. (Of course, there are plenty of other attributes, like various forms of noise and distortion.) If you read a good review of a digital camera, they'll point it at a test piece and measure available lines of resolution, just as they would for film.
A 1000 pixel display can display 500 line pairs, which is 1000 lines.
-- oldthinkers unbellyfeel ingsoc
an open source image editor Cinepaint is in the middle of a rewrite to convert from GTK to FLTL, Fast Light Toolkit to free up some memory and CPU cycles by using a more spartan interface. The pro's want they work to be pretty, not their software.
Apocalypse Cancelled, Sorry, No Ticket Refunds
Don't worry, there are currently no IMAX digital installations showing The Dark Knight. I was talking about next time. If you see The Dark Knight it in IMAX, you're pretty much guaranteed it's running from 70mm film. I have heard that this is at Nolan and Pfister's request, but cannot confirm. As for regular, non-IMAX theaters, Fandango.com will tell you which ones are running DLP, down to the specific auditorium. As far as I have been able to see, their information is accurate.
DLP is always 2K or less. TI has not made or announced any chips at greater resolution. 2K is currently the highest pixel count chip anyone can buy. In fact, for several years, it was only 1280x1024. Can you believe some people actually wanted to put that in theaters and call it a day? Ridiculous. Thankfully, better heads prevailed and we now have 2K at minimum, for better or worse.
The upcoming IMAX digital system will be two 2K DLP projectors "stacked", so the maximum resolution will be 2K x 2K. To get even up to 4K x 4K, they would need four projectors at least, which they have said they aren't doing. It's really not going to compare very well up against their traditional 15-perf / 70mm systems, but apparently they are in dire financial straits and want to save money.
(Not sure why my original post was modded "troll", but everything I said is correct and verifiable.)
Free Hans!
You're all almost right. In VFX when we say "2k" we don't mean exactly 2048. These days "2k" usually means 1920, but in the past each studio used a slightly different number, as when your shooting to 35mm film as output, the math to pick a digital width is pretty fuzzy.