kelvins and watts
- Thread starter thome
- Start date
ThereIsNoLimit
Active member
2k is 2000 watts, 5k is 5000 etc.
Color temperature is measured with kelvins.
For example:
5600 kelvin = daylight
http://en.wikipedia.org/wiki/Color_temperature
Wikipedia will provide you with a more thorough explanation.
Color temperature is measured with kelvins.
For example:
5600 kelvin = daylight
http://en.wikipedia.org/wiki/Color_temperature
Wikipedia will provide you with a more thorough explanation.
Ryan Patrick O'Hara
Veteran
Lights are commonly rated in watts.
When talking about motion picture lights, the wattage and color temperature do not really effect each other. This is because the lights are premade from the manufacturer to perform at a certain wattage at a certain color temperature.
What will effect color temperature is line voltage reaching your lamp. But that is another story.
As far as watts are concerned, it is important to know what the bulb is rated at, the type of bulb, and amperage conversion. You see, the watts rating will not only tell us approx how bright the unit will be, but it can let us figure out amps and keep us from overloading our electrical circuits at home.
I'm sure you are familiar with 150w, 300w, and 600w lamps. But if a light has a (k) at the end, it is NOT referring to Kelvin (color temperature). In this case, the (K) stands for 'Kilowatt'... an abbreviation for 1,000. It's just a fast way to refer to bigger lights such as a 1k, 2k, 5k, etc. If we didn't do this we would refer to them as 1,000w, 2,000w, 5,000w, etc.
It is VERY important to know the type of light you are using! Watts may seem like a measurement of light intensity output, but it's not! Watts are about power consumption. The reason we tend to think of it in terms of intensity output, is because we often use the same type of lights (incandescent filament style), therefore we can make connections about how bright a light will be based on it's power draw.
If you are using special lights that are NOT incandescent, they will still have wattage ratings, but the light output will be much different. These lights include HMI, Fluorescent, etc. These lights are more efficient. Lights turn energy into heat and light. HMI and fluoro's turn more of the energy they use into light versus heat, when compared to incandescent. Therefore they either use much less wattage and put out more light (such as fluoroscents) or they use the same amount of wattage and put out much more light (such as HMI).
Theoretically a 1k HMI will put out about 3.5-4x the amount of light while using the same amount of watts.
Finally, the wattage tells you how much you can put on a circuit. For all intensive purposes, let us pretend we are simply using edison plug 120v lighting units. Most houses with 120v circuits can only hold 20amps. Some older homes only hold 15amps. 1,000 watts = 8.3amps. Because of safety and ease of math, filmmakers like to round the number to a simple 10amps. This is called a light's "Paperweight". Therefore, if a house has a 20 amp circuit... it can either hold one 2k light (2,000w=20amp 'paper'), two 1k's (1,000w X 2 = 20amp paper), and etc.
In summary, wattage does effect color temperature, but since most bulbs are manufactured to be used at a specific voltage, wattage, and operating color temperature there is nothing to worry about. Wattage is abbreviated in kilowatts (k's) when it is in the thousands. Nothing to do with Kelvins. Wattage can tell us how many lights we can use on a circuit because it is related to power consumption. Wattage can give us a relative idea of intensity output because we are used to working with them. Other lighting types will use the energy to make different ratios of heat and light, therefore different.
I hope that helps.