1. 4 Characteristics of Light
intensity, color, direction, and quality

2. Intensity
Intensity or brightness can vary from candlelight to bright sun.

3. Color
Light can also vary in color. In the camera, this can be adjusted by the white balance control, or the color can be corrected with image editing software using the color balance controls.

4. Direction
Self explanatory

5. Quality
Unlike quantity, there’s no device to measure light quality. When we discuss the quality of light, we are talking about how “hard” or “soft” it is, that is, how hard or how soft the shadow looks. Try this: place a portrait subject in direct sunlight at noon. The overhead light will create deep shadows in the eyes, neck, etc. The nose shadow will be sharp and distinct.
--Educational Use Courtesy: Shutterbug