I'm setting up a small greenscreen studio (room is only 12' x 14'), and doing research on the best way to light the greenscreen backdrop. I didn’t know much when I started, have found out a lot, and thought I’d share what I’ve learned for those in the same boat. I’d also like to open up a topic specifically about supersaturation.
I read, somewhere, that “The best way to enhance an object's color is to hit it with light of the same color,” and it grabbed my attention, particularly as the physics seem to make sense.
I did a lot of web research, and found the following:
-Hitting a green backdrop with green light is called supersaturation.
-If you’re as new to lighting as I was, it takes a while to learn to refer to bulbs as ‘lamps,’ but it’s pervasive professional terminology, so just get used to it. I slip every now and again, however.
-In lighting a backdrop the goal is even lighting, and it really pays to grasp the concept that “The bigger the surface area of the key, the softer the results will be.” This means that tube fluorescents will have serious advantages over most other tools (a long glowing tube has greater surface area than most point source lights). My setup is too small and low budget to consider softboxes for the backdrop, though inexpensive diffusion is always an option, even if you loose some efficiency and increase your potential for spill.
-I had originally planned on using a light kit with daylight (5500k) fluorescents, and putting inexpensive green gels over them. But that would have been seriously inefficient (having a source at one temperature, and filtering out that temperature for one that the source isn’t producing much of), and there’s a better way.
-Color theory / temperature physics are a big mouthful to get into, but essentially, both light sources and objects reflecting light can have their color temperature measured not in degrees Kelvin, but in a coordinate system that more specifically measures color. (see http://en.wikipedia.org/wiki/CIE_1931_color_space)
-In that system, a very pure green is measured around 520-550nm. Check out this illustration which you've probably seen before:
http://upload.wikimedia.org/wikipedia/commons/thumb/b/ba/PlanckianLocus.png/533px-PlanckianLocus.png
-Kino Flo (and others) make Fluorescent bulbs that radiate that specific, intense wavelength. This is not a conventional bulb with a coating that only lets out one color. It is / radiates that color and that color alone. They have a whole line of them in Chroma colors called ‘Visual Effects.’ See: http://www.kinoflo.com/Kino Flo lam...Colors/Visual Effects and Designer Colors.htm
-The bulbs aren’t that pricey. $20 for an older, larger style T12 tube bulb, in 2’ and 4’ lengths.
-However, a newer design is called a BIAX bulb (or lamp). It’s a double tube, shorter, 21”, and much more efficient in power to light ratio.
-The bulb / lamp that I’ve got my eye on is 55 watts and costs $30, and is widely available: Kino Flo 55C-K5X 55W Kino 550 Green Compact F55/CFL 21” 2G11 4Pin
I want to use it. I’m going to need a fixture. More below.
I read, somewhere, that “The best way to enhance an object's color is to hit it with light of the same color,” and it grabbed my attention, particularly as the physics seem to make sense.
I did a lot of web research, and found the following:
-Hitting a green backdrop with green light is called supersaturation.
-If you’re as new to lighting as I was, it takes a while to learn to refer to bulbs as ‘lamps,’ but it’s pervasive professional terminology, so just get used to it. I slip every now and again, however.
-In lighting a backdrop the goal is even lighting, and it really pays to grasp the concept that “The bigger the surface area of the key, the softer the results will be.” This means that tube fluorescents will have serious advantages over most other tools (a long glowing tube has greater surface area than most point source lights). My setup is too small and low budget to consider softboxes for the backdrop, though inexpensive diffusion is always an option, even if you loose some efficiency and increase your potential for spill.
-I had originally planned on using a light kit with daylight (5500k) fluorescents, and putting inexpensive green gels over them. But that would have been seriously inefficient (having a source at one temperature, and filtering out that temperature for one that the source isn’t producing much of), and there’s a better way.
-Color theory / temperature physics are a big mouthful to get into, but essentially, both light sources and objects reflecting light can have their color temperature measured not in degrees Kelvin, but in a coordinate system that more specifically measures color. (see http://en.wikipedia.org/wiki/CIE_1931_color_space)
-In that system, a very pure green is measured around 520-550nm. Check out this illustration which you've probably seen before:
http://upload.wikimedia.org/wikipedia/commons/thumb/b/ba/PlanckianLocus.png/533px-PlanckianLocus.png
-Kino Flo (and others) make Fluorescent bulbs that radiate that specific, intense wavelength. This is not a conventional bulb with a coating that only lets out one color. It is / radiates that color and that color alone. They have a whole line of them in Chroma colors called ‘Visual Effects.’ See: http://www.kinoflo.com/Kino Flo lam...Colors/Visual Effects and Designer Colors.htm
-The bulbs aren’t that pricey. $20 for an older, larger style T12 tube bulb, in 2’ and 4’ lengths.
-However, a newer design is called a BIAX bulb (or lamp). It’s a double tube, shorter, 21”, and much more efficient in power to light ratio.
-The bulb / lamp that I’ve got my eye on is 55 watts and costs $30, and is widely available: Kino Flo 55C-K5X 55W Kino 550 Green Compact F55/CFL 21” 2G11 4Pin
I want to use it. I’m going to need a fixture. More below.
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