Measuring light
Two ways of measuring light is CRI, the Color Rendering Index and the Kelvin color temperature. CRI measures the strength of light and how consistent it is. CRI values are on each piece of professional lighting equipment and the best piece of information you can learn is to never buy a lamp that has a CRI below 90%. You can find useful information about CRI on GE’s site, including graphs displaying the color consistency.
Kelvin measures the color of light. The two lights used most frequently in filmmaking are tungsten and daylight. Tungsten, which is a red/orange color, is about 3200 degrees Kelvin, Daylight, which is bluish is about 5600 degrees Kelvin. These values are not heat temperatures, they measure color in a range from black on the low end to white on the high end.
Light kits
There are three different sets of lights we use at school. Arri are tungsten lights and they use Fresnel lenses which concentrates light and directs it straight ahead. Lowell are also tungsten lights and Kino lights are fluorescent lights that are color accurate to either daylight or tungsten. The key thing is to not trust your eyes or the LCD on the camera, trust the monitor.
You can control the light by adding on elements such as barn doors, scrims, gels, gobos and diffusers.
Handling electricity
WARNING WILL ROBINSON: Be very very careful when dealing with electricity and make sure yhou understand how to handle lights before using them. I’m giving you a brief overview, don’t rely on what I say alone.
I do my best to explain about calculating the load your lights are putting on your electrical system. Watts, Amps and Volts are the three variables. You get to do the math everytime you set up lights so that you never blow out the circuit.
Watts / Volts = Amps
Amps x Volts = Watts
Lighten up
Finally, a little more information about matching the color of lights. Don’t be so precise, Leave a little room for variation in color within a scene. As long as it matches your intentions, bear in mind that in the real world, we’re looking at multiple colored light sources all the time and don’t think anything of it.
Chapter times
- 00:08 This week
- 012:9 Lighting terminology
- 02:48 The color of light
- 03:51 CRI
- 05:42 Kelvin color temperature
- 06:40 Light kits
- 08:41 Scrims, gels, barn doors
- 11:22 Changing color with gels
- 13:20 Electricity
- 16:57 Cookies and gobos
- 18:10 Don’t try to match exactly
- 20:34 Close
