First the lighting kit.  For the absolute cheapest possible lighting setup, I’d recommend the following 3 light kit made by Impact.

This kit is cheap at $204 for what you get.  The smaller light on the boom arm is great for back light on your subject, and the two larger scoop lights and umbrellas can be used for key and fill lighting.  Not a bad simple setup.  I used this exact kit for years when I first started lighting for video.  The draw backs of an economy kit like this are that the fixtures aren’t as rugged, so they take a bit of TLC when setting up and carting them around if you want them to last.  Also the scoop lights don’t give you many options for controlling the light output.  Basically they just puke a bunch of light out. 

If you need more control of your lighting and want a kit that will be a bit more rugged, I’d recommend the following kit made by Lowel.

This kit gives you a little more control of your light with the addition of the barn doors.   Using the barn doors you can block the light from shining on your back drop and limit it to your subject.  This can be desirable in a case were you want to light the back drop differently then your subject, maybe with a color gel, or a gobo effect.

Finally, to either of the above kits I would add this softbox.  A softbox is great at giving you a nice even key or fill light depending on the look you are going for.  Even with a softbox you can create nice texture (the desirable kind) on your subject by adjusting the angle of the softbox relative to your subject. 

So now you’ve got your basic lighting kit together, where do you begin setting it up?  

Let’s look at what I would consider a good starting point for your lighting setup, it’s what I’ll call a basic 3-point lighting look.  It will produce a nice evenly lit subject and is a good starting place from which you can begin to experiment from.  To achieve this look, place your key light, which would be your highest wattage light roughly 45 degrees from your subject.  Next place your fill light on the opposite 45 degrees.  Usually the fill is slightly less wattage, but not always.  The goal of the fill light is to “fill” in the shadows created on the face by the key light, but a little bit of shadow creates depth so you don’t want to eliminate it completely.  I usually use the softbox for the key and a light with an umbrella, or sometimes just a direct hard light, but at a lower wattage for the fill.   Here is an example of this type of lighting setup.

The third light in this setup is the back light.  Notice how her hair on the upper right side has lighting highlights on it?  This is the back light.  Without the back light she would have looked very flat and lacked 3 dimensionality and depth.

There you have it.  A simple, cheap lighting setup for an interview video.