URSA Cine 12K – Blackmagic’s RGBW Sensor Technology Explained

Opinion

by Leon BarnardYesterday

This is a guest article about the Blackmagic URSA Cine 12K by Leon Barnard. Leon is a director, cinematographer, and editor with a passion for training the next generation of filmmakers. Through Team 2 Films, he provides valuable insights into Camera equipment and DaVinci Resolve, helping creatives refine their craft.

We recently had the opportunity to shoot with Blackmagic’s URSA Cine 12K LF. While Blackmagic has been producing incredible cameras for the past decade, many consider this to be their first camera targeted at high-end prestige productions. In other words, a camera that can compete with industry standards like the Venice, Alexa and V-Raptor.

As 12K features prominently in it’s name, it’s easy for conversation to focus on it’s resolution. It prompts questions like, “Does anyone need 12K, have compromises been made to achieve such a high resolution and what’s it like to shoot with?” 

We’ll answer those questions shortly, but first there’s something way more revolutionary about this camera that no one seems to be talking about! The technology behind it’s sensor. We’ve sifted through the publicly available documents to better understand this incredible technology.

This article is based on Team 2 Film’s breakdown of the Cine 12K’s sensor technology.

Learn more by watching the video:

RGBW Sensor Technology

Almost every modern camera uses a Bayer Colour Filter Array (CFA). That includes the Alexa, Venice and V-Raptor. Bayer sensors use a repeating pattern of red, green and blue photo-sites that repeat on a 2×2 grid. In each 2×2 segment, there are two green photo-sites, one red and one blue. In contrast, Blackmagic have developed a new CFA. It repeats on a 6×6 grid, and uses a mix of red, green, blue and white photo-sites.

This design has at least two key advantages:

1. Typically, as the resolution of a sensor increases, the size of each photo-site decreases and therefore the sensors low-light capabilities suffer. That’s not the case with Blackmagic’s design. White photo-sites are able to absorb more light as they don’t have a colour filter in front. When combined with the colour data from the red, green and blue photo-sites, this greatly enhances the sensor’s sensitivity in low light.
2. Most cameras have a limited selection of resolution options. You either shoot at the sensor’s native resolution, or if you want a lower resolution there are often compromises involved. For example, the Red V-Raptor uses windowing to shoot lower resolutions which changes the field of view. The Sony Venice can shoot 4K using the entire sensor, but that downsampled image cannot currently be recorded in X-OCN. On the other hand Blackmagic’s unique sensor architecture allows in-sensor scaling from 12k to either 8k or 4k with no artefacts, no windowing and no change of codec.

Let us explain how.

Blackmagic’s Unique Sensor Architecture

In each 6×6 grid, half the photo-sites are white, (also known as wide-band photo-sites). The remaining half is split evenly between red, green and blue, (also known as narrowband photo-sites). That 6×6 repeating pattern is split into macro cells. Each macro cell contains two diagonally opposed wide-band photo-sites, and two matching narrowband photo-sites.

When the camera operates in 12k mode, each photo-site is read individually. When the camera is switched into it’s 8k or 4k mode, the two narrowband photo-sites in each macro cell are paired together, as are the two wideband photo-sites.

As a result when processing each macro cell, instead of the camera having to read four individual values, it only has to read two. This is why the sensor readout is twice as quick (approximately 6ms) when working in the 8k or 4k mode.

When the sensor is in that mode, it’s super easy for the camera to extract both a high-quality raw 8k image and a high-quality raw 4k image. It makes sense because that 6×6 filter pattern is now made up of a grid of 3×3 macro cells. Four and eight both divide into twelve with factors that are aderivative of three. A different filter kernel will be used to process the 4k image and a different one to process the 8k image.

This is absolutely huge! This camera can deliver an un-compromised 4k, 8k and 12k open-gate image from the same sensor.

While this camera has 12k featured prominently in it’s name, thanks to this incredible technology, it’s equally as capable as an 8k or 4k camera. You could even argue that it’s more capable as an 8k camera given the fact that the pixel pairing technology dramatically reduces sensor readout and improves the signal to noise ratio, providing better low light performance.

You can think of this technology as being like a three speed gearbox. A car might be able to rev up to 7000 RPM, or go 120 miles per hour. The truth is that most of the time you don’t need that sort of speed or those sorts of revs. The gearbox converts that power into something useful that you can use at lower speeds. Third gear connects the engine to the wheels with a 1:1 ratio letting you use all 12k. When you drop down to second or first, you get more torque… because that 12K is being condensed into 8k or 4k.

Image Quality of the URSA Cine 12K

Whether Bayer or RGBW, any sensor CFA has the potential to introduce unwanted artefacts. We set out to see if there were any defects in the Cine 12K’s image. The cityscape below is a torture test for any camera. The fine details and repeating patterns will very quickly highlight any moire or aliasing issues that a camera has. It’s not an unreasonable test, as it’s typical of the kind of scenes anyone would film.

We’re pleased to report that no matter how far we zoomed into the image we were not able to find issues. But don’t take our word, see for yourself in the images below or better yet in our video.

We wanted to see if the Cine 12K LF could thrive under challenging production conditions. So we planned a fashion style spec shoot at the Barbican Center in London. This wasn’t a manicured shoot, it involved a great deal of low-light mixed-lighting scenarios.

See the results for yourself in our video. Finally, to eliminate any subjectivity, we shared our test footage with Tashi Trieu, an experienced LA based colourist. His interview is included in our video.

Conclusion

The Cine 12K is disruptive. In my opinion, its stats are groundbreaking in almost every category.

It shoots 12K with an RGBW sensor, comes with 8tb of storage and has integrated 10gb network connectivity. On top of that, it has a 6ms (approx) shutter readout in 8k mode, it can shoot up-to 224 frames per second, has internal ND and costs under $15,000.

Most cameras seem to be compromised in some way. They might have EVERYTHING but cost the same as a mortgage deposit. Or they might be affordable, but lacking features. The Cine 12K LF doesn’t seem to have any significant compromises. It’s incredibly affordable and well featured. About the only thing that we could critique is it’s size and weight but that’s not an issue for largeproductions that have the necessary support to manage a large camera package.

The Venice, Alexa and V-Raptor are incredible cameras. It’s difficult to say which camera is the best, because each excels in different regards. Regardless, from what we have seen, the Cine 12k LF delivers incredible quality that allows it to compete with established high-end cameras. When a complete Cine12K LF package can be purchased for less than $15,000, it’s a very hard camera to ignore. Rent one or visit your local supplier and go see for yourself.

Editor’s note: Don’t forget to also check out our extensive Blackmagic URSA Cine 12K Lab Test that we published recently, and the entry of the camera in our Camera Databases.

What do you think about the Blackmagic URSA Cine 12K? Let us know in the comments below.