Sony Nex 6 590nm Conversion, Sony 16-50 Lens
To convert a digital camera to Full Spectrum involves removing the UV/IR Cut Filter [ Hot Mirror ] that covers the CMOS sensor, this allows all wavelengths of light to hit the sensor. However with no filtration the image will be a bit soft as no lens can focus UV, Visible and Infra Red light to the same point, but by simply adding a filter to the front of the lens in use, will allow photos to be taken in whatever type of light is desired. So adding an IR Pass filter will block UV and visible light and only allow IR through to the sensor and the results will be exactly the same as an IR Conversion with the same wavelength of filter but with the advantage that you can simply change the filter's wavelength or to pass UV or some other effect for Astro work.
To convert a digital camera to Infra Red involves removing the UV/IR Cut Filter [ Hot Mirror ] that covers the CMOS sensor, then a IR Passing [Visible Blocking ] filter is added where the UV/IR Cut Filter was removed. This filter is permanent and the camera will only be able to "see" the IR light that the filter passes.
Why convert a camera to Full Spectrum or Infrared, Can't I just give more Exposure?
Why convert a camera to Full Spectrum or Infrared, well the photos below are taken with a 21mm lens and a Hoya R72. The first on an unconverted camera is taken at 1/20th at f/2.8 with the camera set to a whopping 65535 iso!!, the second at the same time, with a Full Spectrum Camera, was taken at 1/200th at f/5.6 with 100 iso. The IR Cut filter in the unconverted camera is losing a massive 15-16 stops of IR light!!.