Before going into changing the lighting, you may be able to reframe your photograph.
If you don't need the bright area, or the dark shadow area, crop one or the other.
Now, let's look at how contrast can be changed by modifying the lighting in a scene.
There may be less contrast at a different time of day, or on a cloudy day.
When taking pictures indoors, use bounce flash if you have a flash that can be tilted toward the ceiling.
The light from the flash will illuminate the entire scene, rather than just the objects near the camera.
When you set your camera to the Night Portrait exposure mode, the flash will illuminate the scene near the camera.
The camera will also select a shutter speed so that the background will also be recorded.
Movement may be blurred due to the selection of a slow shutter speed.
Use fill flash to add light to the shadows on a sunny day.
On digital SLR cameras, set the exposure mode to P.
Then, press the button near the flash hat pops it up.
If you're using a point-and-shoot camera, press the button with the flash icon until you see ON.
The flash will go off until you press the flash-icon button back to the A (automatic) setting.
You have to be close to your subject.
Some cameras allow you to adjust the brightness of the flash with flash exposure compensation.
A reflector is held near your subject, and is aimed at the shadow area.
Light reflects off of the reflector, and fills in the shadow with more light.
A reflector can be improvised.
You probably don't have an assistant to hold a reflector.
Look for sunlight bouncing off of a white wall, or a red brick wall.
Or, have the model hold a newspaper as a reflector..
If you have someone who can hold a reflector for you, use the circular fabric reflectors, such as those made by Photoflex.
A Polarizing filter will darken blue skies.
Use a graduated neutral density filter to reduce contrast in landscapes.
The next two sections describe these filters.