Wattage for green screen lightning What is the minimum wattage for four-point lighting for a green screen?

I am planning to use led lights in a home studio. Is this enough?


Key light: 300W
Fill light: reflector
Back light: 150W
Light pointed towards the greenscreen: 150W


UPDATE

I think I should rephrase my question to: What settings do I need to use to get a crisp image for a greenscreen? Something like this:



I'm using four softboxes as a light source and one reflector. I was thinking in placing my subject less than 1 m away from the key light and 2 m away from the greenscreen. Something like this



I have a f1.8 lens on a Canon T3i. Do you think this would be enough?
Wattage has nothing to do with lumens, as different instruments provide a wide spectrum of output lumens based on lamp type. For instance, a 1.2K HMI ArriLite would put out more light than a 5000W tungsten lamp. LED, and flourescents are similar, higher output, less watts. 

What is critical for greenscreen work is that you use a monitor with a simple waveform scope. When you light your greenscreen, on your waveform monitor you will see basically a horizontal line. 

You want to get that line as straight and as thin as possible, at 70-72 IRE. Its fairly challenging the larger the screen (you won't be able to do this with the naked eye). 

After your screen is "flat lined". Put in your on camera talent and light them for picture, using dimmers, silks, scrims etc, to cut the light. 

If you do it the other way around, you will drive yourself crazy trying to get the screen at flatline 72.

This will give you the best possible key. If you have variance in your IRE (darker corners, even 5 IRE) you will have to use a looser key (meaning more edge artifacting). 

I recommend for post KeyLight for AE, Lightwrap for AE. 

Also, using a premium screen really makes things easier. Hollywood Rags makes an Ultra Key cloth (order by size) that is ultra bright, the material they use, therefor you need less light to get it to 72 IRE. It really pops. 

Last tip most people don't know, based on your Kelvin, use the same Kelvin for ALL lamps. For your hair light; hit your talent from behind, and gel it using 1/8 magenta CTM.   The magenta is complimentary to green, and will give you a clean edge, specifically on the hair. 

Hope this helps!