Filter—B+W 092 Infrared Pass
Graphs are in nanometers. Visible light is approximately 390 - 650 nm (the human eye can see very weakly into the 700-800nm range). Graphs used by permission of Coastal Optical System.
Buying filters
A great source for filters at competitive prices is B&H Photo. Get filters at B&H Photo.
Spectral transmission — B+W 092 infrared-pass
The B+W 092 filter (50% cutoff at 690nm) is the best all-around choice for infrared work because it allows the differential sensor response that generates “false color”. See the diglloyd Guide to Digital Infrared for details. Get the B+W 092 filter at B&H Photo