With the base of the light panel four feet off the floor, you will have glare on the wet paint, and won't be able to see all of your painting while you work. It will need to be much higher, so the angle of incidence throws the glare down below the level of your eyes.
I recently constructed a light panel on a 48" x 54" piece of 3/4" plywood, by mounting nine fluorescent fixtures for two 48" tubes each on it, with strong eye-bolts at the corners so I can position it anywhere I want, hanging it from chains around the rafters of the old barn that is my studio and dwelling. The panel has 18 Verilux tubes on it, which I have found to be better than any of the other color-corrected "daylight" fluorescents I've tried. I have it hanging at a 45-degree angle, with the bottom ten feet above the floor. I can unplug as many of the fixtures as I care to, to adjust the amount of light this panel throws, as each fixture has its own individual plug, plugged into two multi-outlet strips that are screwed onto the panel. There is still room to add a few incandescent fixtures on the panel if I want to try that, to modify the color temperature. I could screw some halogen floods into those, which would warm the light somewhat, or some of those grow-lights that are used for growing plants indoors. With all the tubes lit, this thing is as close to north light as one can get with artificial lighting, and it does not change in intensity or color temperature. It turns night into day. The only potential drawback, with all 18 tubes plugged in, is that a painting done in this high a level of light will end up looking a lot darker when illuminated by light of lower intensity. I will adjust as necessary by unplugging some of the fixtures, but it is wonderful to have that much light available if I choose to use it.
To get warm reflected light in your shadows, to complement cool primary light, as you mentioned, just place reflecting panels, covered with cloth or paper of whatever color you want, where they will bounce light and color into the shadows on your subject. If you want warm, use orange or light brown. Whatever color is on the reflecting panels is what will register as an influence in your shadows. Or you could use an uncorrected incandescent fill-in light of weaker candlepower than your primary light, perhaps positioned farther away, as a secondary, subordinate light source.
Virgil
