Preserving food, less fighting for food, less roaming to hunt and gather. More stable sense of community. More children. Preserving food, less fighting for food, less roaming to hunt and gather. More stable sense of community. More children.
Contrast sensitivity is the ability of an imaging process to produce an image of objects or tissues in the body that have relatively small physical differences or inherent contrast. The contrast that is to be imaged is in the form of some specific physical characteristic.
In contrast, a real image is one that is formed when the outgoing rays from a point converge at a real location. Real images can be projected onto a diffuse reflecting screen, but a screen is not necessary for the image to form. 1  A plane mirror forms a virtual image positioned behind the mirror. 2  Although the rays of light seem to come from behind the mirror, light from the source only exists in front of the mirror.