Infrared Filter Information:

	http://www.pixelagogo.com/infrared.html - Pixalagogo has some nice shots. Check out his step by step link for a comparison of the 88a and 89b filters
	http://www.geocities.com/thombell/filters/wfir.gif - Good comparison graph of IR filters by Thom Bell
	http://www.abe.msstate.edu/~jwooten/camera/IR_trans.GIF - Spectral graph of 89b, 87c and 87 filters
	http://www.abe.msstate.edu/~jwooten/camera/lense2.gif - Spectral graph of 88a, 89b and 87 filters
	http://www.abe.msstate.edu/~jwooten/camera/lense4.gif - Spectral graph of K89a, K87 and K87c filters
	http://www.besoptics.com/html/hoya_infrared_transmitting_fil.html  - Hoya IR filters
	http://www.photo.net/photo/edscott/ir000020.htm - Good spectral graphs showing a range of IR filters, and some films too.