I am currently setting up my studio, and have everything in place, except the lighting. For my studio light I am planning to use two 9 watt LEDs (equals 2x63 watts), non-dimmable, 4000K. I know 5000-5200K is optimal, but I have a hard time finding bulbs with that temperature, and I think 4000K will be fine.
On the shadowbox-front, however, things are more unclear. I know Mark says it is important to balance the intensity (not the color), of white paint, inside and outside the shadowbox. Still, I don't see why it would be a problem to paint a still life where the whites are darker than the whites on your palette under your studio light. The shadowbox would only act as a "door" into another room, with less bright lighting, and you would only have to tone down the whites for your highlights. (I do understand why the still-life light cannot be brighter than the studio light, as it is impossible to mix a color brighter than white). However, please correct me, if I'm wrong.
Out of all this, my question is: If I use two 63 watt bulbs for my studio light, do I have to use one (2x63=126) watt bulb for my shadowbox, to get the same brightness and achieve a white balance between the studio and the shadowbox?
Also, will dimming an LED bulb change the Kelvin temperature?