Change the brightness of an entire photo
A photograph captures the light reflected from the scene before the camera. Adobe Photoshop Lightroom makes it easy to modify this captured light with the controls in the Light panel. To adjust the overall brightness in a photo, use the Exposure slider in the Light panel.
Define the image with contrast
Contrast is the difference between the bright and the dark tonal values. After adjusting the overall brightness with the Exposure control, experiment with the Contrast slider to refine the balance between the light and dark tones. Some images benefit from higher contrast, while for other scenes, less contrast may look better.
Adjust only the highlights or the shadows
Sometimes, you may want to make adjustments that affect only the moderately bright or moderately dark tones. For example, there may be detail in highlight or shadow areas that you would like to see better. The Highlights and Shadows sliders are designed to target only those areas of the tonal range.
Adjust the brightest and darkest tones in the image
The Whites and Blacks sliders affect only the very brightest and very darkest tones in an image. These are important tones because they help establish overall contrast. Use these sliders to set true black in dark areas where you would not expect to see details and pure white in areas where there are specular highlights, like a bright reflection or a direct point of light.
After you make adjustments with the various sliders in the Light panel, you may need to go back and modify some of those adjustments. Although each slider focuses on a specific tonal range, they all affect the overall image.