User: The greenhouse effect is a result of A. absorption and radiation of energy in the hydrosphere. B. consumption of fruits and vegetables that produce a biofuel. C. absorption and radiation of energy in the atmosphere.
A principal focus or focal point is a special focus: 1  For a lens, or a spherical or parabolic mirror, it is a point onto which collimated light parallel to the axis is focused. Since light can pass through a lens in either direction, a lens has two focal pointsâone on each side.
It may or may not be the actual center of a painting or drawing, but it is always the most important part. Contrast, structure and color are three things that help define the focal point. Focal Point in Your Drawings. Learn the fundamentals of this important and essential aspect of art forgotten by many artists today: the focal point. Focus on Focal Points