Rear Infrared Installation

Rear infrared configurations are used for effects where the particiapnt will touch the screen. There are two possible configurations:

Rear lights. The IR lights are placed behind the screen. The advantage of this is simpler installation and it hides the lights. However, with some screen materials, there is too much reflection from the screen to permit this configuration.

Front lights. The IR lights are placed above and in front of the screen. This configuration is used when the reflectivity of the projection surface is too high to permit the use of rear IR.

General Requirements

Computer. Desktop PC running Windows 7 or XP (64 or 32 bit) at 3+ GHz with at least 512 MB RAM and a PCI Express slot. The computer must have at least one 6-pin Firewire IEEE 1394 port. Note that most machines no longer ship with a Firewire port so you either have to check that it has one or find a plug-in card. If you find a plug-in card then make sure that the computer has an appropriate slot available and that the slot is at least one space away from the graphics card so that you don't block the fan.

Video cables. Modern video cards tend to have digital DVI outputs but DVI cables will only go a few feet. Fortunately, DVI connectors nearly always have an analog side channel which can be run up to 20 feet without problems. Much further than that, and you may need to consider going to a high end component solution such as the RapidRun System. If the output from the computer is DVI you need a DVI to DSUB adaptor. The cable shown to the left is DSUB and the adaptor shown is DVI to DSUB.

Projector. Projector of sufficient brightness for room. Projectors come in two broad technologies: LCD and DLP. LCD projectors will always work with any of our effects, however only some DLP projectors will work and must be tested in advance.
A brightness of 1500 lumens is typical in a dark room. Brightness varies with the ambient light in the room, but the only way to tell for sure if a projector is bright enough for the room is to test it. Projectorcentral.com is a good place to comparison shop for projectors although you should ignore the MSRP and price compare at other sites.

Lighting. Our work should be displayed in a room with low light which does not vary -- this requirement is extremely important. There should be little or no sunlight, and no strobes or bright lights near the projection surface. The brightness of the projector will affect how much light can be tolerated, the more ambient light there is, the brighter the projector needed to overpower it. Light levels for the projection should be similar to those acceptable for projecting a movie with the same projector. If you would be comfortable watching a presentation or movie on the projector, the lighting is adequate. In a darkened room, 1500 lumens is typically sufficient. However, the only way to tell for sure if a projector will be bright enough for a given room is to try it out. If lighting conditions change while the system is installed, the system may need to be re-calibrated. Note, people often worry that the requirement for low light implies that visitors won't be able to see their way; remember, however, that the projector itself is a very bright source of light, so when the projector is on, the room will be well lit.

Projector mount. The projector should be hard-mounted in a place where it will not move nor be subject to vibrations. Projectors that are mounted high (typical of shadow configurations) should be mounted upside down. The easiest way to do this is to buy a model-specific mount. Alternatively, you can cut a mounting board for the projector which can be done by the following method: Find screws which fit into the projector screw holes; place these screws into the projector and mark their heads with a pencil; press a piece of plywood which has been cut to approximate size of projector onto these screws leaving marks; drill out those marks and affix the board to the projector with the screws; affix the board to the ceiling or high shelf using appropriate fasteners such as sturdy zip-ties, rope, or metal brackets. Be sure that the projector will not move after it is mounted.

Camera (provided). A Firewire Camera will be supplied with the software. The camera has a standard 1/4" threaded mount on the bottom and back plate.
Note that if the camera is powered by the 6 pin firewire cable there is no need for a power connection near the camera. If you use a 4-pin firewire then you need power near the camera.

Camera Mount. A camera mount is not provided because such mounts tend to be specific to the installation. In general, it is best if the mount has a ball-socket head to give flexibility to aiming the camera. The mount shown on the left is least desirable because it has only a pivot head not a ball head like the other two.

Camera Cable. 6-pin Firewire cabling to run from the camera to the computer. Runs over 16 feet must use amplified cables such as these from pccables.com. For very long runs, you may need to use a fiber-optic repeater such as this one from Unibrain. Note that laptops do not have 6-pin firewire connections but rather typically 4-pin. This will work but with the addition of an external power supply for the camera.

Power Cables. Power supply cables for projector and camera,power extension cords if needed.

Software (provided). Our software, written in custom C++, shipped on a CD, together with an installation specific hardware copyright key which plugs into a USB port.

USB Key (provided). Our software requires a hardware USB key to copy protect it. This is provided with the software and connects to any USB port on the computer

Speakers. For effects that have sound, speakers should be provided and pointed near where the participants will stand.

Infrared light fixtures. For installations that use infrared light, we suggest using theatrical lighting canisters. We recommend Optima Lighting Par-38

Light Bulbs. Use 100W incandescent flood lights. These lights put out lots of infrared and visible light.

Light Filters. Because the bulbs put out BOTH visible and infrared light, filters are used to block the visible light and let the infrared pass. Use Lee High Temperature Filters HT 026 (bright red) and HT 172 (lagoon blue) along with a diffuser Lee 216.

Camera filter (provided). A camera filter with the same Lee filters will be provided that will go over the camera lens.