Full-Spectrum and IR Conversions
The CCD and CMOS sensors used in digital cameras are sensitive to UV, visible and IR light. Since most photography uses only visible light to create images, camera manufacturers always use filter cover glass over the sensor to block IR and UV and pass only visible light. Without the filters, there would be strong color shifts and a hazy look when trying to take standard, visible light photographs.
While a few cameras are full-spectrum out-of-the-box, most cameras must be converted to shoot infrared. The process involves removing and replacing the original cover glass so IR light can reach the sensor. If you go this route, you have several options to choose from and the modification can be done with a wide variety of cameras.
One option is to make your camera full-spectrum by removing the sensor filter and passing UV, visible and IR light. A full-spectrum conversion is versatile since you can use a variety of filters to pass or cut wavelengths and shoot in visible, infrared or a combination of both.
With IR conversions, all or most of visible light is cut with the replacement cover glass. In the majority of cases, the original cover glass is swapped for an IR pass filter that blocks all UV and visible light up to 720 nm. The other available options change the pass wavelength either deeper into the IR spectrum or into the visible spectrum.