Digital cameras can be modified to full-spectrum and have different infrared filters used in the front of the lens for greater freedom in IR photography.
In July 2010, using a full-spectrum Canon Powershot SX120IS specially-modified for myself, I took this series of images to illustrate the effect of full-spectrum images and the effects of images with different IR filters. Each IR image was shot with its own custom white balance to match the IR filter in use.
Full-spectrum image with a full-spectrum modified digital camera.
Full-spectrum image with a full-spectrum modified digital camera.
Infrared image with a full-spectrum modified digital camera.
Infrared image with a full-spectrum modified digital camera.
Infrared image with a full-spectrum modified digital camera.
This experiment again demonstrated that as the transmission wavelength was increased (deeper into the IR spectrum) the exposure time is also increased. It was shows that images in the higher IR spectrum tend to look soft, hazy and have less colour and less contrast.