12.19.2006 11:34 AM
Grass Valley’s LDK 8000
The Grass Valley LDK 6000 multi-format camera was first launched in 2002, and rapidly rose to be regarded as the most popular camera for high definition and multiple definition applications worldwide. Sports fans will be used to the look of the LDK 6000, as most of the world’s remote broadcast trucks rely on it. Those operators love it because, as well as meeting 1080i and 720p standards with excellent quality, it also produces sparkling standard definition pictures, allowing trucks to work in HD one day and SD the next.
In many ways, the LDK 6000 camera was instrumental in moving HD from the premium end of the market to center stage. HD production is fast becoming the norm. For example, the Asian Games in Doha, which take place during the first two weeks of December 2006, will follow July’s FIFA World Cup in being an all-HD production. That has been brought about because broadcasters can create systems that offer all the production values and operational flexibility that they have enjoyed in SD, but with the additional bonus of sparkling HD image quality.
Technology has rushed ahead, too, and the continual application of Moore’s Law allows us to pack more processing power into the camera. In part this is to meet new challenges—such as 1080 line progressive pictures at 50 or 59.94 frames per second—but primarily allows us to give the camera operator more facilities and functionality.
THE LDK 8000, BORN FROM THE LDK 6000
The time was clearly right for a new generation of high definition camera from Grass Valley. But we could not start with a blank sheet of paper: Our customers already have fleets of LDK 6000 cameras and associated equipment like large lens adaptors and camera control units. They have made a considerable investment, which they certainly cannot afford to throw away. Any new camera has to work alongside current units.
This is the background behind the design of the LDK 8000, our new HD camera launched at IBC in September. We had reached the limits of what we could do with the original design, so we developed a new camera. In doing so, we kept what we knew was desirable from the LDK 6000, and we redeveloped where more modern technology could offer improved performance to meet today’s requirements.
So, for example, while the optical block for the LDK 8000 is completely new, the sensors themselves are the next generation of the HD DPM+ frame transfer CCDs used in the LDK 6000.
While some people are talking enthusiastically about CMOS sensors, we have yet to see anything that can deliver the image quality we know our customers demand. We believe that our own way of managing frame transfer CCDs will provide the right images for at least one more generation of cameras.
We have retained our dynamic pixel management (DPM) system, too. This uses a sensor that is 1920 pixels wide, as you would expect, but 4320 pixels high. This allows us to switch the pixels to get true native resolution whatever the image format. The new generation developed for the LDK 8000 uses an improved design to reduce noise and allows us to clock the pixels out fast enough when 1080/50p or 60p becomes a requirement.
From the CCDs, the signal goes to a brand new analog-to-digital converter, now running at 14 bits, and from there to the video processing section. Here we have created a single custom chip to handle all the video processing tasks in the LDK 8000.
Putting video processing into a single chip brings tremendous benefits, most obviously in speed of processing but also in power consumption and consequently temperature. It also gives us very generous reserves of headroom for future development, even at high speeds. This in turn allows us to implement features that our customers demand from us, such as improved color balancing and gamma correction in the camera, and even reverse image scan enabling the use of cinematography lenses if required, something that is likely to be a major requirement as prestige drama and even sitcoms come to be shot on HD cameras.
One seemingly negative development on the LDK 8000 is that we have removed the composite video output, so you can no longer plug in a standard NTSC or PAL monitor or viewfinder. In fact, adding circuitry to create the composite output is a significant cost in building the camera, and omitting it saves the customer more than enough to buy a good quality flat panel display, connecting via the HDMI output which we now provide.
Another of the key reasons for the original camera’s success was that it connected to its base unit over standard triax cable, as installed in every major sports venue around the world. While these venues will no doubt be installing permanent fiber circuits in the future, the changeover is not going to happen overnight, and so the LDK 8000 retains its ability to work with triax.
A new triax adaptor has been developed, with both improved signal-to-noise performance and the capability of driving even longer cables. We rate its output as working with up to 1200m of triax—which is more than enough for most sports and entertainment requirements. It is a fairly conservative figure, though, and while we do not believe that there will be many applications in which this will be a problem, the range can easily be doubled using an optional triax repeater, which simply connects in line with the triax cable.
Grass Valley has provided a fiber option for the last couple of years—essentially sending triax format signals over fiber—and from launch, the LDK 8000 also supports this. However, it is clear that the future of HD television demands a more sophisticated fiber solution than anything currently offered by any manufacturer, and we will be talking more about an innovative new approach in the future.
COMMAND & CONTROL
Camera control units designed for the LDK 6000 family can, with a simple software upgrade, operate with the LDK 8000, again giving operators the flexibility to mix and match new cameras with their existing equipment.
This includes Grass Valley’s unique C2IP system, which uses a network to control the cameras. While originally designed to make interconnections in a studio environment easier, this has been used in some extreme applications recently. In Sydney, the start of a fun run race was covered by a camera two miles from the truck, linked by two microwaves, one for the pictures and one with C2IP control.
That distance though, is far outshone by NBC Universal, which installed additional LDK 6000 cameras at events in the Torino Winter Olympics and shaded them from its base in New Jersey—around 4,000 miles away—using C2IP over a data circuit.
The new Grass Valley LDK 8000 high definition camera, which is already shipping, is designed to be a partner—as well as a successor—to the market leading LDK 6000. It is physically and electronically compatible, allowing the same mounts, lenses, cables and controllers to be used.
The continued development of the proven imager means that the inherent quality of the pictures is retained, allowing old and new cameras to work alongside each other and freely intercut. At the same time, inside the LDK 8000 are huge advances. These provide better, quieter, cleaner images now, and form a strong platform for the future on which dramatic further developments will be built.
Richard Everitt is the HDTV cameras product manager for Grass Valley. He is based in Breda, The Netherlands.