Note: planetMitch here – this is an analysis of the news from Clayton, our Chief Moderator on the planet5D forums – he's helping me cover some of the NAB news today since there's so much going on.
This is hugely important for RED to stay in the battle for top camera sales. Not only must they compete with Arri Alexa's but also Sony's new F55, which has a global shutter. (And now of course the 4k Blackmagic camera which has just been announced). Basically, the global shutter mimics film in that the issues of skew and rolling shutter up to this point were a big tip off that the camera used was a digital one.
Anyone shooting from a car or a helicopter is intimately aware of the difficulties this posed. Further quick pans on a tripod could also create problems.
The Global Shutter unit is important because it essentially overrides the CMOS sensor in the camera. What this means is that instead of a rolling exposure where the sensor is read from top to bottom (thus creating rolling shutter issues with verticals turned into diagonals if the sensor reads too slowly compared to the movement of the camera) this new add on makes exposure by fully opening and closing a digital shutter at high speed in front of the sensor.
This shutter is like an LCD that is composed of millions black pixels. When turned on it is black and opaque. When turned off it is transparent.
It also can be turned on and off incrementally, which means that it can also function like a variable ND, with no issues related to infrared contamination or vignetting.
Red global shutter
The RED MOTION mount not only incorporates an integrated 8x Electronic ND filter in adjustable 1/100 stop granularity, but also overtakes the sensors timing to give you a true global shutter. All integrated and controlled by the camera UI. Eliminates Shutter Judder and defeats spatial aliasing.
(cover photo credit: snap from reduser post)