Shooting portraits using natural light is sometimes a challenge.
The best situation is when the sun is behind clouds and your model is lit with very soft and diffused light. This type of light is non-directional and it produces an effect of subject wrapping. There are no strong lights or shadows, therefore no details are lost. The unpleasant shadows under the nose and eyes are almost invisible. If the light is too soft, your model will lack any light accent and in that case you can use a fill flash.
When positioning your subject please remember that you never should have the sun poiting directly into your subject’s eyes. It is the worst position. You should do exactly the opposite, have the sun come from your subject’s back. That way it will nicely highlight your model’s hair. And if you use a fill flash to light the model’s face, you will have a great exposure.
Even when your subject is facing the sun covered with clouds, use just a little bit of fill flash to brighten the eyes.
In front light situations there is no depth, no textures, and the details are washed out. In harsh direct sun ligth it is advisable to use a lens hood to protect your lens from sun rays and elliminate lens flare (the bright little circles or hexagons that appear on the image when you take photos with front lighting) and reduced contrast. When the light is hard, using a reflector will help to bounce some light back to the model’s face and that light will not be as hard as directly from the sun. There are 5-in-1foldable reflectors that you can buy for about $30. Alternatively you may use a simple plain white board of a sufficient size.
Another way to take pictures under direct hard sun light is using a diffusion panel that usually comes in 5-in-1 reflectors. Naturally you will need an assistant who will hold the panel for you blocking the sun light.
Digital cameras offer much less dinamic range than film cameras. So in order to get your image without blown out areas in the bright day light, just go into shade.
It is a good idea to shoot in Aperture priority mode but pay attention to your shutter speed as well because it may increase when the sun is getting down and your photos may become blury. If you see your shutter speed going over 1/60th of a sec, increase the ISO or switch to Shutter priority mode.
There are three elements that a photographer must understand when taking pictures: light, composition and subject. Every image has its appropriate light. If the light is not good, the photo will be a failure.
Side lighting can be used for separating the subject from a background. This trick can turn a common photo into a winner. The three-dimensionality of the subject: shape, texture, shadows, it all becomes more obvious.