North light is traditionally the best lighting for artists to use. North light or natural light coming from an above north facing window is ideal but not always attainable for most unless you have that in mind before choosing or building a studio space. If you are fortunate enough to be able to afford a custom built studio then more power to you! :) for the rest of us, sometimes artificial lighting is our only means to achieving that "perfect" lighting. Also. It's that when I state "above" I don't necessarily mean from the ceiling. It can be at an angle or simply higher up the wall.
Yes, it's the bulbs that make the difference. I use CFL bulbs. Def NOT incandescent bulbs. CFL's take a little bit of time to fully light up but they are worth the little bit of time it takes. I specifically use 3 bulbs in my floor lamp. Each bulb base can rotate making it easily for me to adjust. I also put diffuser on them since the bulbs alone can be quite harsh. Really I should spread the light around by installing track lighting but I haven't gotten around to doing that yet.
- Color Temperature: I like the way 5000k -5500k looks. It's a white light. Not too yellow or too blue.
- Brightness: 2600 Lumen/each bulb. Since I use 3 bulbs that's a total of about 7800 Lumen which I like. Another way to measure brightness is with watts. I use 120 watts total, 40 watts/bulb
- CRI Rating: over 80 is good. 90-100 is best.
CFL's are def more energy efficient and eco-friendly than incandescents but they are still fluorescent lights and fluorescent lights contain toxic mercury. I try to paint only during the daytime so I can utilize the natural light that comes in through my east facing window and minimize the amount I have to use the CFL bulbs.
I am currently looking into maybe getting neutral (white) LED lights. They are more expensive but last longer and don't have toxic mercury.
Also, keep in mind that there is a difference between the lighting used for painting vs display (like in a gallery).