So you’ve decided to incorporate a bit of pixel mapping into your show (either that or you’ve bought a media server and just want to know how to use that extra feature tucked away in the advanced menu). Instantly you will ask yourself, “What kind of lighting fixture would be good to use?” And that’s when it starts — the quest to find an LED fixture that lets you map video to each and every pixel on its front panel. How easy is that? Well, let’s take a look.
One Pixel, 3 LEDs
Currently there is no shortage of LED lighting fixtures on the scene. They come in every size and shape imaginable. But which ones work well for pixel-mapping? Not many. The reason: the number LEDs, and how they are combined in the fixture. Part of this is the effort to keep costs low when building the fixture. Another reason for this is that any substantial number of pixels that would be better for mapping video images would require a Red, a Green and Blue LED for each pixel. So for every single pixel in the image, there would have to be 3 LEDs (or more expensive homogenized LEDs), and that would add up very quickly in terms of sheer physical size of the moving head of the fixture.
Most LED lighting fixtures are further limited in the number of control channels the manufacturer writes into the DMX protocol. In an effort to keep the number of channels to a minimum, typically all individual Red, Green, and Blue LEDs will be combined together into three control channels, and it is by combining these three channels into different percentages that colors are created by the fixture. The GLP Impression is an example of this type of fixture. What this boils down to is that if you’re just looking for simple color mixes of shades of Red, Green, Blue, Cyan, Magenta, Yellow and all variations thereof, you’re in luck. But if you’re in search of something a bit more dynamic than that, then you have plan to specify a lot of them in your design.
But don’t lose all hope, pixel mapping fans, there are some LED fixtures available that do allow the user to access each and every pixel on the face of the moving head. Well, there are two at least, and they both come from High End Systems. Both the Showpix and the StudioPix are fixtures in High End’s line of Pixelation luminaires designed to do exactly what this article is about: display video images on an LED moving light.
Showpix and StudioPix
What the Showpix and StudioPix offer is both an onboard media server that stores content that can be displayed on the fixture, but both also offer the user the ability to pixel map additional content from an external source across the fixture’s LEDs. In the Showpix, 127 individual LEDs can be accessed and 61 in the StudioPix. There’s only one drawback to having this much control: if you use the Extended protocol of the Showpix, each unit takes 451 DMX channels. That’s practically 1 universe per fixture if you intend to program using both the onboard 411 pieces of optimized content as well as use Pixel mapping with an external source and standard RGB programming controls. While not as big of a problem in an ArtNet or DMX over Ethernet control network, that would be a massive amount of channels to manage from a programming standpoint in a system with more than just a few units. And combined with the low resolution of 127 (or 61) pixels per head, you have to weigh the decision of using an external source for pixel mapping at all very carefully.
Several products are available that only allow video images to be displayed on their pixels, which means a very low number of control channels is required (if any). VersaTubes and Solaris+ LED Curtain are two of these types of creative LED products. Other types of LED fixtures offer additional control channel options for accessing more of the LEDs on the fixture, such as the PixelLine 1044. The PixelLine 1044 is an RGB linear batten fixture featuring 1044 high intensity LEDs. And they can be controlled in a variety of DMX modes ranging from 3 up to 54 channels of control for each of the RGB cells in the batten.
Video Panel on a Moving Yoke
However, very few moving head LED Video panel products exist currently, with one that stands out in the U.S.: the EPV762 MH, the high res LED Moving Head Video Panel from Elation. Each panel offers a 64×64 LED pixel grid on which video images can be displayed. While this is not pixel mapping in the same sense of the word as pixel mapping on a Showpix, the panel itself is a moving yoke, allowing the video image to pan and tilt. Using only 6 channels of control, and with a 7mm pixel pitch, this small yet higher resolution video display fixture is actually extremely functional and easy to program using any standard media server and lighting console.
All in all, pixel mapping can be a fun and dynamic addition to an otherwise static LED lighting rig. With a little creativity, mapping video images to LED fixtures like Impressions and PixelLines can help to solidify a design and further integrate video into scenic pieces and across lighting trusses. The pixel count per fixture might be extremely low, but it will definitely be noticeable to the audience…and that’s what it’s all about!
Other products that can be used in pixel-mapping configurations include the Mega-Lite Bright Stripe and Pro Color Strip from Mega Systems Inc. The Bright Stripe is controlled in eight segments on Mode 2 or 16 segments on Mode 3 (selectable on the unit’s display).
Mega Systems Inc.’s Pro Color Strip does pixel mapping when on mode P by controlling each LED on the unit. -ed.
