Easy to install and use the Spyder 4 generates a ICC profile for your PC screen. Calibration is essential whenever we do the RAW photo development with Lightroom or Photoshop retouching, for not doing anything. The software speaks French. It is possible to calibrate a projector connected to a PC as a monitor. However for a home cinema Datacolor offers HDTV kit is a scam for HC projectors because you can adjust the brightness and contrast. It is better to use the software that recognizes the HCFR Spyder 4 as a probe. It is much more complex to use but gives spectacular results. So with the same 4 Spyder can both use the Datacolor software for PC display and HCFR software for home cinema projector in use. Just after my purchase Datacolor Spyder released the 5. Thanks Amazon for not having anticipated the announcement!