23rd January, 2012

Stereoscopic 3D legalisation

Since its foundation in 1989, ONSIGHT has expanded from a London-based broadcast hire business into a full service production facilities company. Also located at Shepperton Studios, ONSIGHT specialises in film and television production, post production and distribution.

 

ONSIGHT’s activity encompasses every link in the signal chain and is certainly not confined to 2D. Over the years, we have worked on many 3D broadcast and digital cinema projects and invested in extensive research and development to make 3D production easy and effective for our clients.

 

Although the creative potential offered by 3D is inherently exciting for producers and audience alike, the content needs to be of the highest quality to guarantee an enjoyable and memorable viewing experience.

 

The challenge

 

Legalisers are an efficient way of helping edited programmes pass broadcasters’ technical quality-assurance requirements. They automatically correct parts of a picture that do not meet established criteria for RGB, YUV and composite colour space level specifications.

 

The complication we addressed was that existing compliance methods meant that stereo images were processed as separate left and right eye passes. These then have to be recombined afterwards onto HDCAM SR 422 3D format. This is both time-consuming and costly. Moreover, we want to guarantee that the legaliser would process images for each eye in exactly the same way. Our existing process was good, but we thought it could be better.

 

The solution

 

We approached Eyeheight, one of the most experienced designers and manufacturers of video legalisers, and asked if the company would be able to develop a legaliser that could process the left and right images of a stereoscopic 3D signal stream in a single process. This would provide unquestionable consistency and considerable cost savings. Within a week Eyeheight produced a working model, the LE-3D, which we tested to our full satisfaction.

 

Operation

 

Eyeheight’s legaliser range includes onetouch presets for all major standards, therefore making it all-but-effortless to use anywhere in the world. It has three modes of operation (composite, RGB and YUV), all controlled via a set of menus which define all of the adjustable operational parameters.

 

The LE-3D is controlled via Eyeheight’s generic Flexi-Panel. Four LED-backlit pushbuttons provide access from the top menu. Each subsidiary menu contains up to three parameters which are adjustable via rotary digital potentiometers. The buttons are colour coded, orange for navigation between menus, green denoting a menu with a single variable, red a menu with two or three variables, and yellow for information display. This makes the system very easy to drive, particularly when you are working live or near-live. Full control of clip and knee parameters is provided for minimum and maximum levels. If the knee values are set to the same value as their respective clips, the LE-3D performs hard clipping.

 

A crucial feature of the LE-3D is that left and right stereoscopic channels are processed identically. This means there is no need to each adjustment twice and, more importantly, ensures that both channels are processed in exactly the same way.

 

Stereoscopic 3D legalisation

 

The result in terms of the measured and subjective quality of the resultant content has fully justified the investment. The Eyeheight LE-3D legaliser is now used on the back of our 3D grading and finishing suite and in our machine room for tape-to-tape transfer and standards conversion work. There is nothing else like it available on the market today.

 

The LE-3D proved a vital component on the awardwinning work for ‘Flying Monsters 3D with David Attenborough’. ONSIGHT, Sky 3D and SGO Mistika supported Atlantic Productions with this project and together won the IBC2011 Special Award for exceptional 3D vision. Other examples of ONSIGHT using the LE-3D are Atlantic Productions’ new film ‘The Bachelor King 3D’with David Attenborough', and Eagle Rock Entertainment’s concert film ‘Peter Gabriel: New Blood Live In London 3D’.

 

By Rik Tester, ONSIGHT Chief Engineer

 

TV-Bay magazine January 2012