Canon announces BT.2020 support

[Jon Fairhurst]

Canon announces BT.2020 support for the C500 camera and DP-V3010 display.

Canon U.S.A. : About Canon : Newsroom

Canon U.S.A. : About Canon : Newsroom

For those not familiar with BT.2020, it is an exceptionally wide color gamut associated with Ultra HD. People generally know about the "more pixels" aspect of UHD. BT.2020 (and HDR) are part of the "better pixels" aspect of UHD.

Are there other cameras and monitors out there with BT.2020 support? If so, it would be great to compile a list...

[Jack Zhang]

I believe Sony's S-Gamut supports within and beyond the color range of Rec.2020, and that's in the Sony F55 and F65. Correct me if I'm wrong.

[Jon Fairhurst]

Beyond Rec.2020 would be impressive. Many see Rec.2020 as a container that will deliver smaller actual gamut. To my knowledge, no display currently delivers the entire Rec.2020 range, though it is possible for a display to receive and re-map a Rec.2020 signal.

See the Rec.2020 gamut range on the CIE color chart here: Rec. 2020 - Wikipedia, the free encyclopedia

Of course, if you really want a big container, go for the Academy ACES workflow:
http://www.fxguide.com/wp-content/up...mut.jpg?8ccd0d

Regarding the F55 and F65, I wonder if they offer the Rec.2020 container as an option. If S-Gamut goes beyond Rec.2020, it must be using a proprietary container.

[Alister Chapman]

Rec 2020 isn't a container, it's a range. A range that can be put in many different containers or many different signals.

Gamut's and the container that stores it (codec) are totally different things. You can record the 2020 gamut with just about any codec. A better codec will record a wide gamut with better precision, but the range will be the same with any codec.

In addition you must remember that the recording gamut may be very different to the gamut that the camera can actually capture. For example a lower cost camera might have a large recording gamut, but the sensor may not be able to fill that gamut. It's very difficult to make the color filters needed to allow a sensor to capture a very large gamut.

Think of a recording codec as a bucket. Think of the recording gamut as a type of liquid and think of the cameras sensor as a scoop.

You can put lot's of different liquids (gamuts) in the bucket (codec), but you will only fill the bucket by the volume of a single scoop (sensor range).

A great example of this would be Sony's F5 ad F55 cameras. You can record S-Gamut (bigger than BT-2020) with any of the codecs, XDCAM, XAVC, SStP on both cameras. But only the F55 has a sensor good enough to fill the bucket. The F5 only fills it about 3/4 of the way.

So it's all very well adding BT-2020 to a camera's recording or output capability, but can the camera actually take full advantage of it?

[Brian Drysdale]

I suspect you'll need to be more careful with the greens found in many types of lighting. The old video cameras used to be quite blind to that part of the spectrum when shooting in mixed lighting, while film picks it up and you are into plus or minus green gels matching lights.

[Jon Fairhurst]

In fact, the whole topic of color temperature is really interesting in wide gamut shooting.

Let's say you are shooting in daylight. The light is blue, so the blue sensors will tend to saturate quickly. The green and red sensors will have a lot of headroom and the camera will be able to capture extremely saturated reds and greens. Conversely, filming under tungsten lights will allow more headroom for saturated blue objects. One can do similar things with colored filters on the lens - bias the light in one direction to allow capture of subjects in the opposite direction, then normalize.

If you think about it, the camera gamut is limited by the color filters on the sensor. By adding an additional color filter in front of the lens, one is effectively changing the hues of the color filters.

[Brian Drysdale]

I suspect you'll be into testing your sensor the same way as you do with film stocks. DPs already test cameras to test various aspects of the images they're creating.