The simplest answer: for consistency from the filmmaker’s ultimate reference “Hero” studio monitor to your home video display. There is only one 1080p HDTV video standard and only one 4K Ultra High Definition video standard that all video displays need to follow. All home televisions and projectors do not display the correct image from factory but can be correctively calibrated using specialized equipment. If you want the incredible visual and artistic impact of the of all that you watch – from films to live sporting events – then corrective calibration is 100% necessary.