@Ritchie A December 7, 2018
For the 2017 season the Christmas Spectacular Starring the Radio City Rockettes received a complete technology update providing lifelike dynamic scenery, including an 8K LED upstage display driven by the VER M8 LED Processor.
One of the primary requirements for this installation was to use Two Sample Interleave (2SI) 4K formatting for quad-linked 3G-SDI throughout the facility, instead of the more prevalent but somewhat ad-hoc square quad division (SQD). 2SI finally introduces metadata indicating which pixel quadrant each channel is representing and makes it more difficult for the user to mis-patch the quadrants. In addition, each SDI link carries a complete 1080p representation of the 4K signal making intermediate monitoring a little easier with existing HD infrastructure.
Matching colorspaces across all display technologies (in this case, LED and projection) is still not well managed in a production workflow, and LED is a particularly bad culprit with most LED displays running in a 'vivid' or native color gamut mode. Expanding a color gamut to greater than 100% of its specified area can be as bad if not worse than compressing it for representing accurate color depending on how the gamut mapping is done. Typically gamuts with incorrect primaries also result in non-linearities within the gamut as well, leading to issues such as missed secondary color targets. To address this for Radio City, a conversion matrix was implemented to target as close to the Rec. 709 gamut as is possible with the material science limitations of the light sources.