People generally look best when you photograph them in soft light. That’s why studios bounce the studios lights off of big umbrellas or through big “soft boxes” to widen and soften the light. The umbrella or soft box mimics the nice soft light you get on a “cloudy bright” day when there are just enough clouds to soften the light and minimize shadows.
But photographers shooting portraits outdoors don’t always get a choice as to whether or not the harsh light of the sun is softened by nice clouds. If it is a bright sunny day, one option is to shoot in “open shade” like the shady side of a building so the light comes from the big blue sky, not the sun. The light in open shade is nice and soft.
The disadvantage of open shade is the cool (bluish) color balance thanks to the blue sky, so your subject’s skin will look unnaturally bluish in tone. The solution if you are using a digital camera is to set the white balance on your camera to “shade”. This will warm up the image so it looks more natural. On some cameras, the “shade” setting is indicated by a little icon showing shade on the side of a building. Check your manual to find the shade setting on your camera. The shade setting on a digital camera is like using a warming filter with a film camera. That is something to remember if you are shooting a sunset that needs a little more zip. Just change the white balance from “sunlight” to “shade” and you will have a warmer sunset.
Another option is to set a custom white balance. Your camera manual will show you how. Generally this involves taking a picture of a truly neutral toned surface (like an 18% gray card) in the same light as your subject, and use this photo to set a custom white balance on your camera. Setting the white balance on your camera will affect the jpeg files but not the RAW files. However, the custom white balance you choose might determine how your raw conversion software converts your RAW files.
Raw conversion software like Adobe Camera Raw (ACR) makes it very convenient to change the color balance of your images when you process them in your computer. When you open the RAW files in ACR, dragging the TEMPERATURE and TINT sliders is a fast and effective way to get just the color balance you want. The color balance for the portrait above was tweaked using the sliders in ACR.
If you are shooting color slide film in open shade, use a yellow-amber tinted “color conversion” filter in the 81 series (weaker effect) or 85 series (stronger effect). This will counteract the blue tint from shooting in the shade.
If you shoot color negative film, you don’t need to worry. The final color balance of the photos is adjusted by the person who makes the prints.
There is a lot more information about light, color temperatures, white balance settings, neutral tones, 18% gray cards, and portrait photography in my photography book, Digital Photography Exposure for Dummies.