Publications


Low-Cost LED Wall - - Published in TD&T - Summer 2016

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The project was also presented at the International Lighting Symposium 2015 in Hong Kong and at USITT’s conference in 2016.

Abstract

The LED Video Wall project began at Stanford near the end of the 2013-2014 school year when Daniel Cadigan, Stanford’s Shop Carpenter for the Theatre Department, presented the idea of creating an inexpensive LED star drop to our team (LITES – Lighting Innovation and Technology Education at Stanford). The idea grew from a star drop to a video curtain and finally landed on the idea of building a full modular wall that would be comprised of 50 4’ by 4’ panels each with 400 LEDs for a total of 20,000 LEDs. Since the wall was being created by our student group, we knew from the onset that the project would have to be done for as little money as possible; however, that did not stop us from aspiring to have a professional looking product. Our goal for the project was to have an inexpensive, professional looking, modular, reusable, and easy to use video wall. In the end our wall cost roughly 1/10 the cost of a comparable professional product, and many people commented on how professional it looked. 

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More technical information can be found on the LED Video Wall Project Page.

Low-Cost LED Wall sRGB Color Mapping - Fall 2015

LEDBeforeAfter-2

Abstract

We created a large, modular, LED video display to be used in a variety of activities from concerts, to theatrical productions, to art installations. The wall is made up of 50 4’ x 4’ panels for a total assembled size of 20’ x 40’ and an effective resolution of 200 x 100 pixels.

LED technology has always been expensive, primarily due to the high costs associated with producing batches of quality LEDs to create a uniform image. This video wall was made for roughly 1/10th the cost of a professional product with similar pixel density by using inexpensive LEDs and then imaging our panels with a dSLR to measure relative luminance. Furthermore, we used a color spectrometer to record the gamut, white point, and gamma of the LEDs. With this data we mapped the sRGB color space into the color space of the LED wall allowing us to produce content then display it on the wall while preserving the colors in the final image.

These techniques, combined with the hardware and software design, produced a professional looking video wall for a fraction of the cost of alternatives.

More information can be found on the wiki page.

Remote-Controlled Follow Spots - Published in TD&T - Winter 2015

MA control computer

Abstract

The idea of this project came about during the initial stages of designing the lighting design for Ram's Head Theatrical Society’s production of Les Misérables at Stanford University. It was determined that for this show the two follow spots with flat angles in Memorial Auditorium, Stanford’s 1800-seat theatre, were not going to be enough.

As an alternative, an experiment was tried using moving head fixtures as follow spots with live control from WYSIWYG. Traditionally, moving head fixtures have been limited in their ability to be employed as follow spots because they typically require pre-cuing. However, WYSIWYG, while typically used for pre-visualization of the lighting cues to cut down on in-space time, has a communication protocol called AutoFoucs. AutoFocus allows you to move fixtures in the software, communicate that information to the lighting desk, and send it to the actual fixtures. This would allow designers to harness all of the flexibility of a moving head light, but with the added ability to follow an actor, and without the safety risks and time needed to build platforms in space.

We did extensive testing before deciding this technology was ready to be used in a show. We had to: ensure multiple instances of WYSIWYG could talk to a single console, confirm that the console could output the data sent to it by multiple instances of WYSIWYG communicating with it at once, test that the control was smooth and not jagged, and finally, find what control interface would enable an operator to actually follow someone.

Once testing was completed, implementing the technology for the production of Les Misérables was begun. This was thought to be a relatively simple process, but it was found that there were issues to be addressed when scaling up the technology and training operators.

By opening night of the show the operators were as proficient with our remote controlled follow spots as they were with traditional spots. There were no major issues with the system or network during the run of the show, and the overall design of the show was praised for its subtle changes of angle and intensity in the follow spots that were made possible by using moving lights as the follow spots.

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© Matt Lathrop 2015