RED vs. CineAlta 4K

[chuckt]

Can anyone clarify my confusion between RED and Cine Alta 4K.

I read that some major studio feature films have been produced entirely on Cine Alta 4K and that SONY and Panavision are working together to make it the deFacto standard in Film making.

[RCFisher]

That must be the sony CineAlta 4K Projector. I don't even think the new, unreleased in this country, F35 is 4K. The only 4K projector at the moment is the Sony. Also I don't think sony and Panavision are talking these days, they had a falling out over the Genesis I think which is why Sony will release the F35 in the country in 2009 sometime. I did find that Panavision does have a 4K camera, it's a speciality camera for the medical or military market I think.

[Jeff Kilgroe]

These posts were trimmed out of the CF card thread in the main forum...

There currently isn't any CineAlta 4K camera. The only "4K" product Sony has anywhere is their "4K" projector, which is actually only 3.8K if you want to get technical.

[David Mullen ASC]

The upcoming F35 is like the Genesis, a 12MP sensor with RGB stripes designed to create a 1080P 4:4:4 (RGB) signal for recording, usually to HDCAM-SR.

There is no 4K Sony camera coming out in the near future. There may be some odd prototypes floating around like those "Ultra HD" cameras you see coming from Japan, like the 3.8K 4-CCD Olympus camera.

[Gavin Greenwalt]

In all fairness just because the Genesis and several other cameras don't output 4k, they do have almost as many photosites as the RED but are content to supersample.

[Graeme Nattress]

The arrangement of photosites in the Genesis 12mp sensor, being RGB stripe, means it's pretty much fixed to the 1080p resolution. Assuming they're using an optical low pass filter (anyone tested this), that would necessarily limit their resolution to 1080p also, or incur the wrath of aliasing. AFAIK, they don't readout all 12mp then process - they read out 6mp, being 2mp each of red, green and blue binned from the 4mp.

In an RGB stripe system, the RGB samples are no co-sited, but are treated as being co-sited. With Bayer pattern we know that the samples are not co-sited and use that information to extract out more real resolution from the system.

In 3 chip cameras which use pixel-shift, which works great in 4:2:2, I've seen pixel offsets of red and blue from green of up to a pixel (think blue and red halos) when looking at 4:4:4 data. So is their 4:4:4 really 4:4:4 - yes and no! So in that case, the RGB should be co-sited, but are not, and it leads to artifacts because it is not dealt with properly.

It's complex....

Graeme

[Mike Devlin]

These posts were trimmed out of the CF card thread in the main forum...

There currently isn't any CineAlta 4K camera. The only "4K" product Sony has anywhere is their "4K" projector, which is actually only 3.8K if you want to get technical.

Jeff, why do you say it is 3.8k? We have an SRX-R105 projector and it provides 4096x2160 pixels, which is in fact the DCI spec for 4k. For 1.85 content (Vista Vision) you use 3996x2160 pixels. For 2.39 content (Cinemascope) you use 4096x1714 pixels. For 16:9 content (HD) you use 3840x2160 pixels (quad HD). Again this is all exactly as specified in the DCI spec (well, 2.39 and 1.85 anyway).

We use a 16' Stewart FilmScreen screen with motorized masking for the supported aspect ratios for post production. Pretty much any theater will have equivalent capabilities for masking the screen to 2.39 and 1.85, the standard aspect ratios for presentation.

I do not believe there is a 4K presentation standard anywhere in the world that requires more than the DCI spec 4096x2160

[Graeme Nattress]

Yes, at 16:9 it's only 3.8k.

RED requires 4096x2304, which is larger than the Sony can project. I think the DCI spec is short sighted....

Graeme

[Mike Devlin]

Graeme, I always thought of the RED 4096x2304 as the OCN (original camera negative), and like 35mm today (which is 4:3) you select the portion of that image to use for the final theatrical release, which (in the U.S.) is always 1.85 or 2.39. Setting aside anamorphic lenses for the moment, you are cropping the OCN for any theatrical release (35mm or RED). Is that the wrong way to think about it?

It seems very unlikely that theaters will change from the current 2.39 and 1.85 presentation standards. The DCI spec for digital theaters seems well entrenched and is being widely implemented (2K DLP or 4K SRXD). Christie, Barco, NEC and Sony (the only providers of Digital theater projectors today) all support the DCI spec.

[David Mullen ASC]

You have to accept some mild resizing and/or cropping -- for example, if you laser record the 4096 image to 35mm negative for printing, the projected area is 3656 pixels across due to the soundtrack area. So either you crop 4096 down to 3656 or you resize it down to 3656 (I believe that's how the Arrilaser works -- I could be wrong.)

Yes, ideally the DCI specs would accept that 4096 can be both an origination size and a projection size. I guess people are saying that it doesn't currently.

[Graeme Nattress]

DCI spec was designed for film, not for digital. I don't see why there should be such a problem giving people a wider choice in aspect ratios. The problem with the chosen resolution is that it causes issues for 16:9 material, and given that there's going to be a hell of a lot of HD material, shot in 16:9, it would have made much sense to add on those 2304-2160 = 144 pixels to allow for it.

Not to mention the convoluted mastering process for DCI spec (and yes, I know you can get very expensive "solutions", but that's not the point). And that it handles colour space in a bonkers way, speccing XYZ rather than allowing any space with the appropriate matrix embedded as metadata to allow device calibration like an ICC profile. And then there's framerates. It's stuck at 24 (48 for stereo?), which again, is short sighted in the extreme. Rant off.

Graeme

Graeme

[Graeme Nattress]

Actually, I'l have hoped that a spec for digital cinema would be aspect ratio, pixel size, and frame rate agnostic, with defined procedures for any mismatch in those aspects. But that's me hoping too much :-) Just putting in 4096x2304 would have helped.

But ignoring 25fps is madness, as is ignoring other frame rates. I don't like being tied into the thought that cinema distribution should be tied to 24fps, especially when a lot of film material in "PAL" countries has been shot 25fps for easier integration into television standards.

[Mitch Gross]

While they're at it, why not push the DCI spec to 4096x2440? That's what the Phantom 65 shoots and as a resolution measurement purely by the numbers it is so very close.

Mitch Gross
Abel Cine Tech

[Graeme Nattress]

Why not :-) ? Surely the projector would be superb to be able to do 4k 4:3 then even old TV shows could get the full 4k treatment :-)

Graeme

[Jeff Kilgroe]

Jeff, why do you say it is 3.8k?

Sorry, I just didn't complete my train of thought in my post... 3.8K as far as displaying 1.78:1 / 16:9 or the full 4K frame from RED.

[Mike Devlin]

And then there's framerates. It's stuck at 24 (48 for stereo?), which again, is short sighted in the extreme. Rant off.


I agree very much regarding the framerates. It would be nice to bury 24fps and eliminate all the motion artifacts that go with it, or at least "allow" higher framerates. As other have pointed out, 24fps was a limit imposed by 19th century technology and by miserly studio execs trying to conserve film against the wishes of the creative types who (back then) wanted to deliver better motion. David would know better but my understanding is the ASC was the one that insisted on only allowing 24fps (and 48fps for 2K) in the DCI spec. Most of the digital cinema projectors (including the Sony) actually support higher framerates.

We have wandered way off topic...I just wanted to make sure I understood the relationship between the RED OCN and the delivery formats as specified by DCI and implemented in the current Digital Cinema projectors from Sony, Barco, Christie, etc. The DCI spec is ugly, but at least there is a standard to work toward and that is critical for Digital Cinema to take off, so I am happy to work to that standard.

P.S. Uprezzing old 4:3 TV shows to 4K as Graeme suggests is really sick and should be banned in all civilized countries...

[David Mullen ASC]

This is a reprint of Kevin Brownlow's article on silent and early sound speeds:
http://www.cinemaweb.com/silentfilm/bookshelf/18_kb_2.htm
excerpt:
According to Stanley Watkins, head engineer for Western Electric, he and his team checked with the Warner Theatre for the average speed of projection in 1926. They were told 'between eighty and ninety feet per minute' in the big theatres- between 20 and 24 fps- and around 26 fps in the smaller theatres. They settled on 90 feet a minute (24 fps) as a reasonable compromise for the Vitaphone process.[2] The other sound systems began at slower speeds (Fox-Case's first tests were shot at 21 fps), but they, too, adopted 24 fps as standard in November 1926.

As for the restriction of the DCI spec to 24 fps, I don't know the history of that, you'd have to talk to someone on the DCI committee. I'm sure it's possible to update the specs, since changing them is not as problematic as changing physical specs of 35mm projection equipment.

The general goal at the time for the DCI committee (and the ASC members advising them) was to adopt standards that would not be LOWER than what we had already with 35mm projection, as some studios were itching to do (for example, to just make 1080/60i 4:2:2 HD REC 709 the standard for cinema projection, or even 1280 x 720). Hence a 2K and 4K standard at 24 fps -- what they didn't want was ordinary broadcast HDTV being what people saw in a movie theater. But now that these 2K / 4K digital cinema standards are being implemented, we could start considering even better standards.

Today I saw some great-looking 2K presentations of "National Treasure 2" and "Walk Hard: The Dewey Cox Story"... I'm so grateful that we didn't settle for the old 1.2K Texas Instrument DLP projectors showing HD tapes as the standard.

[Manfred Lopez]

They settled on 90 feet a minute (24 fps) as a reasonable compromise for the Vitaphone process.[/I]

Isn't it true that although the frame rate in movie theaters is 24 fps, the actual displayed image speed is 48 fps since each frame is flashed twice onto the screen? I was told in college that human vision starts to mix visually discreet individual steps into imagined fluid motion around 50 to 60 increments per second. So the doubling of the 24 per second frame rate would make sense. Is any of this right?

[David Mullen ASC]

Each frame is flashed twice to reduce perception of flicker but it doesn't reduce motion strobe. To truly reduce motion strobe to create a hyper-real smooth motion, you have to increase the frame rate of the camera (and then project it at that frame rate.)

In the silent era when movies were sometimes projected as slowly as 16 fps, the projectors were triple-bladed so each frame was flashed three-times to reduce flicker. Nowadays, projectors are double-bladed so each frame is flashed twice.

As the article suggests, Edison was thinking originally of a 46 fps standard to reduce flicker and strobing, but it hadn't occurred to him to use a double-bladed shutter in the projector to reduce flicker. And considering how miserably slow film stock was back then, running the camera at 46 fps would have been problematic, exposure-wise, not to mention the extra cost in film stock (and how tired the arm of the cameraman and projectionist would be cranking at that speed... though I guess they would have just changed the gear ratio.)

[Häakon]

It would be nice to bury 24fps and eliminate all the motion artifacts that go with it, or at least "allow" higher framerates. As other have pointed out, 24fps was a limit imposed by 19th century technology and by miserly studio execs trying to conserve film against the wishes of the creative types who (back then) wanted to deliver better motion.
With complete respect, I have to disagree entirely. I don't want all of my films looking like reality television or soap operas. I accept that our perception of why 24p "feels" right has largely been shaped by our continual exposure to seeing films projected this way, but just because it's less "true to life" doesn't mean it's objectively worse. If that was the case, we would be well served to abolish anamorphic systems and their disfigured and distorted bokeh at the same time.

People enjoy motion pictures because they offer a break from "true life;" they present an alternative to our reality. I would argue that 24p is very much a part of that vernacular regardless of where it came from.

[Graeme Nattress]

Haakon, that's your choice, and nobody is taking that (or wants to) away from you. What I was pointing out is the short-sightedness and USA-centric choice of fps.

My comment about TV was there have been lots of TV shot on 35mm film over the years, some of which would look beautiful at 4k, and some of which was shot at 25fps (not 24fps).

David, your comments about people wanting to make HD the projection standard are very interesting. You can sorta see where they're coming from in terms of cost / benefit, but it would be very short sighted given the whole idea of a cinema is to offer a better viewing environment than can be achieved in the home. Surely that would have been the final nail in the coffin of cinema?

Graeme

[Nova Invicta]

Sony have announced they are working on a 4k camera to create a 4K system, as yet nobody other than Sony knows what chip size it will have and whether they can "boast" more pixels or not.
David is right re-sizing is a defacto part of any 35mm image and Red, Dalsa etc will be no different. The myth however just like in stills cameras where the MP war is gradually slowing down is not whether you simply have a 2K, 4K or for that matter 8K sensor but how your colour imatory takes that raw data and converts it into pictures we all see at the cinema, Canon wrote a whole paper on this very subject. Some 4K images I have seen have been far worse that 2K because of this fact, dont get me wrong you want to paint on the biggest canvas but the paints also need to be right and many aspects of digital cinematography are still in their infancy whereas film has over 100 years of legacy (thats why Jim Jannard and other evangelists should still respect film oils & watercolors comes to mind).
Most of joe public think were barking mad and cant see anything wrong with the images they already had and in this i-pod / mobile phone world 2K / 4K /
8K means nothing. Add to this average theatre sizes and 2K let alone 4 or 8K IS more than acceptable.