In the film era infrared film was practically used in aerial photography applications for forestry and camouflage detection, as well as other
scenarios where specific infrared reflectance photographs could be useful. In digital time, the digital image sensors take the place of the films.
There are two ways to do infrared photography now, converting a regular digital camrera into an infrared camera through modifying the image
sensor or put an infrared lens attachment filter in front of the camera lens. With an infrared lens attachment filter long exposure time is required,
appearantly the camera need to be on a tripod. With specialized infrared camrera one can hand held the camera using normal shutter speed.
But this is an on way trip, once the camera is converted to an infrared camera it can only be used for infrared photography. Here I used
"convert", since there is no infrared camera available in the consumer market, an infrared camrera is modified from a regular digital camera,
appearantly you don't want to do this with your main camera.
Hoya R72 is an infrared lens attachment filter, it blocks most visible light and lets 72nm wavelength infrared light passing through.
