Light up everybody
In this episode there's a lot of information
about the character of light and lighting hardware. To our eyes light is white,
but light is always changing color and knowing how to describe it and measure
it is very important to filmmaking.
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, 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 you 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
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