The newest thing to make it to the scene is the comeback of the LED. These little diodes can now be seen everywhere including stoplights and even lighting fixtures. The fact is that their shelf life will outlast any light bulb beyond most statistics. Very few people have had to replace a burnt out LED.

LED's have been restricted in the world of show business use for one simple reason. The blue LED just wasn't happening until recently. We have had red, green, and amber since the beginning of time. But, 5 years ago a Japanese company released the Blue LED, which Blew this industry wide open. It made it possible to duplicate the basic principles of additive color mixing. Just like the basic principles of lighting, mixing red, blue and green to produce white was now possible.

These days, corporate events, large retails stores, and even Times Square are making use of LEDs. Las Vegas is a prime place to see them in operation. We should also make it clear that an LED screen doesn't require a projector. When U2 went out on the Popmart tour with the first LED screen they had no idea what they had started. This of course didn't mean that a star was born overnight. The problems of weather and travel and the fact that it was a new product kept the techs very busy in their efforts to keep them running smoothly. Soon after, Spice Girls and Janet Jackson included the screens into their production.

So how do these things work? Quite simply, LED's are placed in a repetitive order on a panel about 1 square meter wide and 3-4" thick. The number of panels is judged by the size you want the screen to be. The LED's mix the same way as a standard TV picture tube – red, blue, and green. The distance they are apart from each other will equal the quality of the image. LED's that are closer together will give a better image. 1 pixel is made up of 3 LED's ( 1 of each color ). If pixels are spread by 1/2", the pixel ratio is ½.

Surprisingly, the LED techs that video companies are hiring aren't necessarily video guys. Lighting guys are starting to fill the void. The reason being that balancing the 3 primary colors can usually be done more efficiently by the lighting persons' trained eye. Also, a lighting technician will generally have rigging experience plus a knowledge of electricity and electronics. Lighting guys are also pleased to be in a situation where they aren't the first ones in and last ones out of the venue. The load-in and load-out schedule for these things is the same as the sound crews'.

The electronics on the screens are really quite simple. Each panel is made up of about 3000 chips. The chips are replaceable during the show (obviously as long as the they aren't flown in to a place where they are unreachable). The screens are now being built in such a way that they don't even have cable connections between each panel. They just click in to place with internal connections that lock together. Also, the new generation screens can even be run in fierce weather conditions. Most of the troubleshooting seems to be on power up mode. Once they are in operation they rarely have any problems.

The screens are being used in some very innovative ways these days. For example, Tool triggers a number of abstract images from the stage onto screens via MIDI. U2's latest tour has these screens working on hydraulics that pop out of the floor. On the U2 set, there's a total of 13 screens that are about 8' wide by 5 ½' tall. The next phase they are working towards is to improve clarity by combining three colors into one LED. This would create optimum resolution. It would also put the resolution to about 2-3 mm. The biggest issue they are dealing with right now is being able to keep clarity at a close proximity. Of course one big scenario sits in the way of this being introduced into our industry – Money. One panel alone costs about 100 grand. Also the surface mounted diodes are currently only available for indoor use.

A Canadian company called SACO was the first to build these screens. Since then there have been a number of companies that have come and gone. The biggest and probably the most reliable company these days is BARCO. They solved a lot of issues and increased reliability, plus they created interchangeable panels. This means that if a panel fails on the road, they can get a local panel a lot easier. The only thing is that the pixels ratio must match. They are the largest distributor of the LED screen at this point in time

So is this the end of the standard projector? Not really. Cost still plays a significant role in the LED screens. A standard projector can be rented for about a 10th of the price of the LED projector. It really becomes a matter of choice; A strong projector can still give a very clear image, but it definitely can't match the intensity of the LED.

 

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