Re: CFL -- Lighting
It all depends on the CFL. Some are designed to approximate white sunlight, others the warm white of the incandescent bulb. Still more have a bluish or greenish cast.
I do wish there was a way to test them in the store to see what they really look like!
The effect the light has can be measured in a spectrogram, which is a graph with color along the bottom (infrared on left, ultraviolet on right, ROYGBV in the middle) and intensity along the side. Sunlight has a straight line across the graph. An incandescent is high in the red zone but otherwise is fairly smooth.
Our eyes have sensors for red, green, and blue. Each of these sensors covers a fairly broad range of each color, so something that is monochrome orange (a single frequency of light) triggers both the red and blue sensors. Some manufacturers will claim that their light bulbs are "full spectrum" when in fact they aren't: if you were to look at a spectrogram of the light you might see spikes at red and green and nothing at orange. But your eye THINKS there's orange there because both the red and green sensors are triggered.
The problem is that while your eyes are fooled, the rest of your body isn't. Your skin cells produce vitamin D, this process depends on light. If you don't have the right spectrum of light hitting your skin, this process might not work as well. There's a lot we don't know about the human body (and even more that I don't know), but I suspect that having the proper spectrum of light is very important to our physical and emotional well-being -- our whole body depends on it, even if our eyes are fooled.
The "Senior Member" designation under my name doesn't mean I know a lot, it just means I talk a lot.I've been a DIYer since I was 12 (thanks, Dad!). I have read several books on various home improvement topics. I do not have any current code books I can refer to. I was an apprentice plumber for two years.