Because the light is not enough! That is why professional makeup artists always need a makeup table with many light bulbs. The light plays an important role to make the look of the makeup is not too thin or too thick. Makeup more evenly, black stains and acne scars that will be covered with makeup can be covered well without any left. In the meantime, perhaps you want to consider buying the Hollywood Mirror as well, so you can improve the result of your makeup.
You do not need to have a special lights dresser, really. The trick, just apply makeup with the help of sufficient outdoor light. Dress in front of closed windows, for example. At least, there is sunlight coming into the room where you apply makeup.
Aside from that, if your face gets acne and wants a flawless makeup result, concealer is the key. As is known, concealer has several kinds of colors with different functions.