Further, most light boxes use fluorescent light, and I have a personal dislike for fluorescent lighting. I decided to improvise some less expensive solution. This is much brighter than ordinary interior lighting, but is still not nearly as bright as sunlight. One could achieve 10,000 lux by using a great many ordinary incandescent bulbs, but this would be a waste since much brighter bulbs are available relatively inexpensively. There is some debate over whether full-spectrum light is necessary in light therapy.
Sunlight is the best known example of full-spectrum light.
Note that spectrum is not the same as brightness. Even though the fluorescent light emphasizes only certain frequencies, it can still be as bright as a full-spectrum light. The energy in full-spectrum light is simply dispersed over broader ranges of the visible frequencies. If anyone knows of comparable products which I should discuss here, please let me know. The wider the beam, the less bright the light on any given spot, since the total light is more spread out.