Have you ever hit the town after artfully applying your cosmetics, only to catch your reflection in a window and think, Where did all my makeup go? The reason your face lost its pop between leaving your bathroom and arriving at the party has nothing to do with your makeup's staying power: It's all about the lighting.Turns out, there are definitive rules when it comes to doing makeup for different types of light. The best photographers and makeup artists swear by them — and it's not just about wearing more or less. We consulted two industry heavyweights to learn the rules for ourselves.If you're familiar with Robin Black's blog Beauty Is Boring , then you know she's just as skilled behind the camera as she is with a makeup brush — she's a lighting pro! She splits her time between the two disciplines for publications like Elle and Allure, and big beauty brands such as Clarins. For even more pro guidance, we spoke with makeup artist Beau Nelson . He calls the better half of Hollywood his clients — Nicole Richie, Gigi Hadid, Chrissy Teigen, and Kristen Stewart, just to name a few — acting as their trusted makeup artist, from the red carpet to shoots to daytime appearances.Ahead, these two powerhouse professionals break down exactly what you need to know to put your best face forward, in every type of lighting.