Lights. Camera. Action.

The first step towards our physical assembly for the FTIR table has been purchased—we have ordered a pack of Osram SFH485 IR LEDs. Creating a FTIR table requires a lot more to be done to the display surface, as opposed to a DI device where most of the extras are separate from the display.

For our display we are going to use a sheet of acrylic that is 24×18 inches (~ 61×46 cm) and placing the lights along the 24 in. sides. At this point, until we do some tests and more research, we are planning to use about 15 LEDs per side.

We ordered a pack of 100 LEDs from Digi-Key which should give us some extras to create another table or experiment later.

Once we have our our camera and acrylic we plan on doing some tests to see the best number of LEDs to use. From some blog posts we hear 1.5 centimeter apart, from others we hear that you should only need about 12 per side. We’ll see what works best when we get the equipment all set up.

Also, make sure to check out Jason Modisette’s great FTIR Screen Design Applet to help understand and visualize total internal reflection of the infrared light within the acrylic sheet.