Full-spectrum modified digital cameras can be used to do infrared photography. To do IR photography with a full-spectrum digital camera, an IR filter is attached to the front of the lens.
Probably for convenience, most photographers choose to modify their digital cameras specifically for infrared by having an infrared filter fitted inside the camera. However, modifying for full-spectrum allows the photographer to choose the infrared, or even ultraviolet, transmission desired for the purpose, probably for a scientific application.
With a Hoya R72 (720nm transmission) filter and an unbranded 950nm transmission filter, I tried them using a full-spectrum modified Nikon D70 belonging to my company Camera Clinic. This was my first use of a full-spectrum digital camera. Shot at Grampians National Park in Victoria state of Australia, the images below show the expected reddish cast of a full-spectrum digital camera due to sensitivity to red and infrared.
Forming 2 sets of 6 images each, they were shot in a consistent sequence as follows:
[1] Auto white balance without IR filter
[2] Custom white balance without IR filter
[3] Auto white balance with 720nm IR filter (Hoya R72)
[4] Custom white balance with 720nm IR filter (Hoya R72)
[5] Auto white balance with 950nm IR filter
[6] Custom white balance with 950nm IR filter
Photography with a full-spectrum modified digital camera.
Photography with a full-spectrum modified digital camera.
Photography with a full-spectrum modified digital camera.
Photography with a full-spectrum modified digital camera.
Photography with a full-spectrum modified digital camera.
Photography with a full-spectrum modified digital camera.
Photography with a full-spectrum modified digital camera.
Photography with a full-spectrum modified digital camera.
Photography with a full-spectrum modified digital camera.
Photography with a full-spectrum modified digital camera.
Photography with a full-spectrum modified digital camera.
Photography with a full-spectrum modified digital camera.
This experiment also demonstrated that as the transmission wavelength was increased (deeper into the IR spectrum) the exposure time is also increased.