Study Room - Infrared Photograpy
According to Wikipedia, ”In infrared photography, the photographic film or image sensor used is sensitive to infrared light. The part of the spectrum used is referred to as near-infrared to distinguish it from far-infrared, which is the domain of thermal imaging. Wavelengths used for photography range from about 700 nm to about 900 nm.”
There are not much options of "infrared" camera for ordinary people to use. However, almost any digital cameras, whether it is a DSLR or web camera, can be modified to turn into a infrared sensitive one. As described in reference 1 (with "Step-by-Step Guide to Removing the Infrared Filter"), it is a complex and risk laden process and better let professionals to accomplish. Yet if one can get one such kind of reworked camera, a completely new worled will be waiting ahead.
After removing the infrared cut filter, "Wratten 25, 87 and 89 filters" or equivalents are need to block visible lights (reference 2).
Below is the comparison between infrared image and monochrome image converted from color image.
Infraread Photography shows some more examples of infrarad photographs.
References
1. How To Remove Infrared Filter From Camera ?
2. IR Digital Camera Mod Keeps Autofocus Intact