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Monster from the Third Dimension

Belden 1694D – 3D HD Video

Well, maybe it’s not a monster, but you can’t go to any professional video tradeshow, convention or seminar without 3D being a major subject. It’s safe to say the majority of motion pictures in Hollywood are now being shot in 3D. It looks like the action-adventure genre, and cartoon animation now require 3D image capture.

It seems like the real ‘watershed’ project was “Avatar” which was shot in a very gentle “behind-the-window” 3D format. I saw one of the 3D rigs used on Avatar and the designer told me that the cheapest part of the rig were the two RED cameras! The rest of it cost over a million dollars. And, while there are a few entry-level 3D cameras, giving a combined 3D single-coax output, almost all the serious shooting is being done with two separate cameras. This also means two separate video feeds, one from each camera.

Separate cameras and separate signals give you the maximum versatility, the ability to manipulate not just camera position and spacing, but any part of either image. To make them easier to handle, those two video coaxes are often combined with wire ties, flex, spiral wrap or heat-shrink. At the same time, it is more than likely that the two cables are the same color, since they came off a single roll. This then requires labels, or color bands on connectors, to tell which cable is which eye, right or left? And if you want to see an image that really looks like it’s from another dimension, just switch right and left signals. So it didn’t take a lot of brainpower to bring out Belden 1694D.

This cable is just two of Belden’s regular 1694A, the world’s most popular HD video cable, with a thin overall jacket holding them together. They are color-coded red and green (“port and starboard” or “right and left”). Other than that, they are the same as regular 1694A, using the same connectors, strip tools, crimp tools, and wire management accessories as before.

It is interesting to note that this dual cable has an alternate video application. That other application is the “poor man’s” version of 1080p/50 (3G) called “dual link”. This uses two standard HD images but combines them into the high-resolution 3G-SDI image. It is often cheaper since it uses old HD chips, just two at a time. It also requires two video coaxes.


So, by using this cable, you can go to 3D or 3G. In fact, since each of these 1694A cables is tested to 4.5 GHz for 3G (1080p/50) applications, it could be used for 3G-3D if such a format ever emerges.

So I suppose it’s no surprise that this new cable design won a “new technology” award at NAB, the big broadcast tradeshow last April in Las Vegas, Nevada. Such a simple idea, but I suppose a lot of great ideas are both “obvious” and “simple” once someone makes them.

Which does lead to some interesting questions. We already make multiple video cables in bundles of 3, 4, 5, 6 even 10 or 12 in some versions. While these were originally intended for RGB and VGA applications, they often use HD and 3G cables such as 1694A as a constituent part. A 10-pack of 1694A could easily run five 3D images. Is there a need for multiple 3D images? For that matter, should there be other versions? Smaller? Langer? More flexible? Super-rugged outdoor? Underwater? Long distance? How about a fiber version?



About Steve Lampen

Steve Lampen has worked for Belden for nineteen years and is currently Multimedia Technology Manager and also Product Line Manager for Entertainment Products. Prior to Belden, Steve had an extensive career in radio broadcast engineering and installation, film production, and electronic distribution. Steve holds an FCC Lifetime General License (formerly a First Class FCC License) and is an SBE Certified Radio Broadcast Engineer. On the data side he is a BICSI Registered Communication Distribution Designer. His latest book, "The Audio-Video Cable Installer’s Pocket Guide" is published by McGraw-Hill.