Is R3D 4:4:4 or 4:2:2?

[Adrian Jebef]

Absolutely not, the Alexa has a nice output image but in terms of pure color rendition the Epic wipes the floor with it. Including skin tones. However with more information comes greater responsibility and the need for greater understanding of the material and processes required to control and manipulate said information. If you like your images spoon fed to you the Alexa/C300 etc. are a good fit. If you want full access to what is really there the only choice is Epic.

My second contention is that saying a GRBG Bayer filter array is 4:2:2 or 100%/50%/50% is like saying that a 4 cylinder is 30% less powerful than a 6 cylinder. Despite the fact that the 4 cylinder is a tuned Subie STI and the 6 cylinder is a Camry. Debayering is a computational act, it uses real, interpretive and calculated information to create color channels that measure much higher than the 4:2:2 or 100/50/50 you imply because no color is absolute, it is made up of components and those can be calculated to a much higher degree of accuracy. Measured chroma resolution here is the important thing to consider because that is the chroma resolution actually available to you when you debayer and process your footage. Is in absolute terms the color resolution lower than the luma? Yes, but by only a small margin and at least at 5K you'd be getting around 4K or more, again tested, usable, measured resolution, not theoretical numbers based on a sub-sampling method that doesn't even apply to RGB. Remember YUV is in and of it's self a chroma subsampling method.
Simply by staying in the RGB space you've saved significant color information from being thrown down the drain.

Put into YUV terms if the Alexa produces a pure 4:4:4 image (It doesn't but I'll go with it) then the Epic produces a 20:16:16 image, which would you choose?

Evin:

It has been my experience that ALEXA and F35 footage has "truer" skin tone reproduction than Epic footage. To me true color reproduction should allow for what is seen by eye on the set to be translated to what is seen on the screen. In order for this to happen a whole lot of technical crap has to happen first. There are steps to the process. Light energy needs to be captured. That energy needs to sampled and then converted (analog to digital) to a numerical value representing the intensity of that energy. This is then scaled into the degree of accuracy of the system: 8-bit 256 values, 10-bit 1024 values, 12-bit 4096 values, and so forth. At this point it is RAW and it can be recorded. This is what the Epic does and what the R3D file represents. But is is not an image. It is not what was seen on set. These numbers need to be crunched, algorithized, transformed, debayered, reborn, interpreted. Debayering is a computational act. It is math. And it does use "real" (discreet), sampled information but it also uses interpretive and calculated (non-discreet) information to turn the math into an image. My experience has been that the accuracy of this process is relative to how the image was discreetly sampled at the sensor. Math can be re-calculated to get slightly better results but math cannot add discreet values that were never present in the first place.

The Epic is an excellent 4K black and white camera. But it's color reproduction I find lacking. The idea that the end user must take on more responsibility and a greater understanding of RED's "mysterious" image-making process is simply silly. Yes, RAW image data can be computationally changed an infinite number of times without (theoretically) destroying the underlining data. But RAW image data cannot "magically" produce chroma resolution that wasn't there (sampled) in the first place. RGB, YUV, XYZ, or ABC do not really matter as they are simply quantitative spaces in which the RAW data will eventually inhabit. Just because I have a 16-bit RAW file or a 10-bit RGB image does not mean that I have all of the luma and chroma information that was originally present in the scene at the time of capture.

I have no interest in which camera system provides bigger and better technical results. My interest is in the system that provides results that are as close to what I see by eye.

BTW: if we say the ALEXA is 4:4:4 at 2K/HD and the EPIC is 20:16:16 at 4K then wouldn't your logic lead us to declare the EPIC is 4:2:2 at 2K/HD?

[M Most]

Absolutely not, the Alexa has a nice output image but in terms of pure color rendition the Epic wipes the floor with it. Including skin tones....

An opinion. One that you are, of course, entitled to. But also one that is not widely shared by the great majority of cinematographers that I know and work with. Epic has many qualities and many reasons to recommend it, especially for features. But at least to this point, what you're claiming is generally not one of them. I would go so far as to say that Alexa has succeeded in its intended market (primarily television) despite Epic's technically superior specs. There are two primary reasons for that: simplicity, and the images themselves. On paper, Red should be winning hands down. But in reality, it's all about the images, particularly in television, which doesn't need the resolution that Red delivers, at least not to this point. The images are what have sold Alexa to the cameramen who have selected it. The simplicity of delivery is what sold it to the producers.

I'm very optimistic that continued refinement of the color matrixing will always lead to "better" (always in the eye of the beholder......) Red images, thus minimizing the first perceived advantage. But if Red really wants to gain a larger foothold in television, they should at least consider integrating HD recording, as both Alexa and F65 do (well, F65 uses a dockable module...but it's built by Sony, uses their codec, and will be updated in lock step with the camera..). That would go a long way to eliminating the perceived complications caused by having multiple color matrices, multiple gamma curves, multiple shooting formats, internal settings, external settings, FLUT, Alchemy, and a host of other settings all available to be used - or abused, as is often the case. Third party solutions are nice, and useful, but it's not the same, especially in that television market that I'm referring to. You don't see a whole lot of Codexes attached to Alexas shooting television shows...

[Graeme Nattress]

But RAW image data cannot "magically" produce chroma resolution that wasn't there (sampled) in the first place

Agreed - so why are you arguing that 1440 chroma samples across an image is better than 2560?

Graeme

[Gavin Greenwalt]

I feel like the question is getting semantically ignored while we all know exactly what he's asking.

Does the green channel have more resolution after debayer? Yes. In my experience blue and red are softer after debayer.

Is it half the resolution? No. Making up bullshit numbers off the top of my head it feels more like (3.8):(3.2):(3)

Does any camera deliver "true" 4:4:4? No.
Does any other camera deliver more red and blue resolution from what I've seen? No.
Does redcode above about 5:1 start to really eat into the blue resolution and sharpness? Yes.
Does film deliver 4:4:4 as meaning "full resolution in every channel"? No. The blue channel in every film scan I've seen is also softer just like RED.
Does Bayer pattern sometimes introduce 'odd' mosaic patterns? Yes.
Are said patterns noticeable at 4k or after supersampling to 1080p/2k? Not since like build 14.

Should 4:4:4, interlacing, pull downs, non-square pixel aspect ratios and tape all be relegated to the dustbin of history? Yes, please for the love of God yes.

[Graeme Nattress]

Pretty good summary Gavin - I'll take you up on one point

"Does any camera deliver "true" 4:4:4? No. " and just add in ",not at it's native sensor resolution, or not without excessive aliasing" but your overall message is well taken.

Graeme

[Adrian Jebef]

Agreed - so why are you arguing that 1440 chroma samples across an image is better than 2560?

Graeme

G:

I'm not arguing that at all. The number of samples is only relevant to the intended target resolution. And the way these chroma samples are handled within the debayering process equates to real, perceivable, on-the-screen color rendition.

[Adrian Jebef]

I feel like the question is getting semantically ignored while we all know exactly what he's asking.

Does the green channel have more resolution after debayer? Yes. In my experience blue and red are softer after debayer.

Is it half the resolution? No. Making up bullshit numbers off the top of my head it feels more like (3.8):(3.2):(3)

Does any camera deliver "true" 4:4:4? No.
Does any other camera deliver more red and blue resolution from what I've seen? No.
Does redcode above about 5:1 start to really eat into the blue resolution and sharpness? Yes.
Does film deliver 4:4:4 as meaning "full resolution in every channel"? No. The blue channel in every film scan I've seen is also softer just like RED.
Does Bayer pattern sometimes introduce 'odd' mosaic patterns? Yes.
Are said patterns noticeable at 4k or after supersampling to 1080p/2k? Not since like build 14.

Should 4:4:4, interlacing, pull downs, non-square pixel aspect ratios and tape all be relegated to the dustbin of history? Yes, please for the love of God yes.

Gavin:

You're getting close but I'm actually not interested in technical resolution whether it be luma or chroma. I'm interested in color accuracy, rendition, and most importantly beautifully natural skin tones. I constantly have issues with how the EPIC records and processes color. Especially skin tones. I find it very disingenuous that some among us would prefer to beat the 2-is-better-than-1 drum no matter what. More resolution (technical sharpness) does not always deliver superior results over fidelity (perceived sharpness).

[Graeme Nattress]

G:

I'm not arguing that at all. The number of samples is only relevant to the intended target resolution. And the way these chroma samples are handled within the debayering process equates to real, perceivable, on-the-screen color rendition.

You're not making a coherent argument.

Graeme

[Graeme Nattress]

Gavin:

You're getting close but I'm actually not interested in technical resolution whether it be luma or chroma. I'm interested in color accuracy, rendition, and most importantly beautifully natural skin tones. I constantly have issues with how the EPIC records and processes color. Especially skin tones. I find it very disingenuous that some among us would prefer to beat the 2-is-better-than-1 drum no matter what. More resolution (technical sharpness) does not always deliver superior results over fidelity (perceived sharpness).

Look Adrain, you've jumped in here and your comments are all over the place, and then you come out with "Actually the ARRI Alexa utilizes a 3K+ Bayer sensor which downscales to 2K/HD for proper 4:4:4 color resolution. " which you know is absolutely factually wrong. From there it's gone downhill rapidly.

The original poster asked what no-doubt they thought was a simple enough question, but in reality the answer is a hell of lot more nuanced than they anticipated. The more nuanced answers have been accurately given as part of this thread, but you're constantly wanting de-rail the discussion along your own lines and that doesn't help us out here. We've had some very good contributions to the discussion, but when you say: "but I'm actually not interested in technical resolution whether it be luma or chroma" you've basically just said you're wanting to discuss something entirely different to what this thread is about.

Graeme

[David Mullen ASC]

Skintone reproduction is as much an art as it is a science and it is highly subjective -- film emulsion designers have spent nearly a century trying to get skintones to look pleasant as much as they have spent trying to accurately reproduce a grey scale or a color chart. In digital photography, it is also an evolving art and science. Some of it is technical, you need enough bit depth, color separation, accurate spectral response, etc. (so as cameras improve, we've seen an improvement in the naturalness of skin) but some of it is also an eyeball thing... and it goes all the way from the design of the sensor to the colorist at the end of the process, not to mention the display technology. We'll never hear the end of this debate, not as long as color photography exists.

But for many reasons, I feel that the skintone reproduction of Epic images is quite nice and a visible improvement from early Red One images. Just as with early film D.I.'s, I think the complaints about caucasian skin looking blandly band-aid pink/tan have become increasingly rare as the science of digital color-correction improves, and as digital cameras improve.