Editor's note: These two letters are in response to Wendall K. Harrington's sidebar ”Video Black, Oy Vey!” to “A Tale Of Two Edies“ (Live Design, December 2006, p. 34).
I've got several suggestions (ranging from crude to super high-tech) for getting a true video blackout that is sufficient for theatre.
#1 Crude: Instead of using a DMX shutter or color scroller with a congo frame, use a ColorFader. This requires some modifications to the clear part of the gel strings in the fader. You'll have to modify (cut a big center hole, or replace with clear gel, depending on usage) in the perforated clear part of each scroll so the triple layers of perforations don't throw your focus out. This will allow something more akin to a fade rather than a chop. It's not perfect, but it works.
#2 Somewhat Crude: Use older 3-gun CRT projectors. These don't send much of anything in the way of image when they are not getting signal.
#3 Fairly High-Tech (and my favorite): There is a company called SEOS that builds flight simulators and VR-immersive environments. They have a new product called Zorro that takes a D-ILA projector, does some magic with the optics, and adds a second focal point in front of the projector. They then put a fourth “K” panel in the new focal point and use that fourth panel to black out all the pixels that are not in use. They claim a 250,000:1 contrast ratio. I've seen it, and it's mighty impressive. The Hayden Planetarium is in the process of installing an entirely new SEOS system starting early in 2007. For more information, visit www.seos.com/Black.
#3A: Sony makes a 10K-lumen LCOS projector in its SXRD line that has a pretty awesome contrast ratio. The added bonus is that these are 4K resolution projectors, so you'll pretty much never see pixelation unless you want to. The “video black” is not quite as impressive as the SEOS, but it's pretty amazing in its own right. For more information, visit http://bssc.sel.sony.com/BroadcastandBusiness/minisites/sxrd_new/flash/index.html.
#4 High Tech and very pricey: Zeiss makes a projection system called ZULIP, which is a laser video projector. It's super-bright and has great color rendition. Best of all, it just turns the scan off when there is a black pixel, so no light is emitted. I only know of two installations, and both are in Germany.
— AJ Epstein
I feel Ms. Harrington's pain.
I don't know if it's something Ms. Harrington could use, but she should look into the projector douser that City Theatrical is selling (Catalog # 4160) — DMX-controlled.
They also have an iris that could probably be adapted for projector use.
— Tom Rodeheaver
Caffeine Media Inc.
New York, NY