Part 2: Current technologies at use in the rental & staging world
Welcome back to our second tour through a third dimension. When last we met, we were discussing the idea of 3D imaging systems vs. the idea of 3D effect systems, and what each of them were used for. Bear this in mind for the rest of the article, as it’s the most important part of all 3D: “There is no true 3D imaging where we cannot present separate images to the right and left eyes.” There. I said it. Now let’s look together at some of the things we may encounter in this third dimension.
But first, let’s talk about what they aren’t. They aren’t “holograms.” At least, none of the ones I’ve seen currently in use in AV are. I know, I know, the ad says they are. You’ll even tell me that the picture that ran alongside the first article in this series called a projected image a hologram. Mea Culpa. But they’re not, and if we’re going to talk knowledgeably to clients, I think we should use technical terms correctly. A hologram is a particular type of 3D image recording, done only with laser (or coherent) light. The light scattered from a solid object is recorded to film, and because of the properties of the particular light and imaging, appears in the final image to be threedimensional. They’re used for all kinds of scientific purposes, and to make paperweights for Sharper Image. But they’re not used in any of the products we’re currently buying.
So what exactly are we buying? Well, as I mentioned, they’re principally used for one of two reasons: either the display of a 3D model (“real” 3D) or for 3D effects for shows. Let’s look at one example of each:
First, let’s talk about “actual” 3D — which consists of working with one of two types of images: models created in a 3D modeling program and specifically rendered to be displayed in 3D, or “real-world” scenes captured with a camera specifically developed or rigged to capture two different (eye separation) images simultaneously. These images are then displayed using 3D monitor or projection systems that use glasses to provide the appropriate image to each eye. These glasses can be active, using LCD shutters to sequentially shut off the left and right eyes, so that each eye receives only the correct image separation, or passive, using either polarization or color separation to keep the two eyes distinct. Color separation, or “anaglyphic” imaging, is the type normally used in commercial movies or broadcast television, where the eyes are covered by red and blue filters. Another method of active imaging is through the use of special monitors or flat panels that use some type of lenticular filter over the display to separate the images, but we won’t cover the use of these since display size limits their use in staging.
Another method of displaying “actual” 3D images is the use of VR headsets, such as the EyeMagine headset, also rarely used in staging because of the expense and the adjustments required for each eye for individual viewers. However, the VR headset provides other capabilities besides viewing the image — it also provides stereo audio and motion sensors, meaning that as the wearer rotates their head, the image moves with it. Couple this with hand sensors, and we have the essential elements of a true virtual reality system. More information and overviews of the “actual” 3D world can be found at www.stereo3d.com/3dhome.htm.
The most common way for staging events to display 3D, however, is through the use of specialized 3D projectors using active eyewear to provide 3D audience viewing of the material (although this can also be accomplished, with some care, using two non-3D projectors). The most recent example of this that I’ve personally looked at is the Digital Projection Titan 3D. After many years of doing 3D with two projectors and passive glasses, the Titan took my breath away (quite literally, because I walked into a countertop while viewing the image). This projector uses active 3D imaging, high brightness and contrast, and an exceptionally high refresh rate to provide 3D images to an audience wearing active glasses. The projector provides an output to an infrared transmitter to synchronize the glasses in the audience.
I spent some time looking at both 3D building models and some captured 3D video footage, and the results are impressive. The 3D images are steady, have virtually no ascertainable flicker because of the high refresh rate, and appear solid. While the most recent example I’ve looked at is Digital Projection’s, the active technologies have made a lot of progress in the last few years, and I’m sure the active 3D projectors from the other big manufacturers have also become quite good, since they all use similar technologies.
The last segment of the market we’ll need to explore will be the use of 3D effects systems, many of which are based on age-old technologies like Pepper’s Ghost (something we’ll talk about, maybe by having a séance with Houdini) in our next segment, “Producing a show for 3D effect,” which will be the third of our three dimensions.