K – “K” has two different meanings, and both apply to movie lights, so one should be careful to differentiate one from the other. 1.: An abbreviation for Kilowatts. There are 1,000 Watts in 1 Kilowatt. It is used when talking about quartz lights or HMIs, as a way to measure their brightness based on their power consumption. A “1K” is a 1,000 Watt light, a “2K” a 2,000 Watt light, etc. 2.: An abbreviation for Kelvin, such as 3,200K for tungsten balance, 5,400K for daylight, etc.