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.
If a photoelectric cell instead of the eye is used to compare intensities, the instrument is called a photoelectric colorimeter. In colorimetry, frequently the entire visible spectrum (white light) is used, and consequently the complementary colour of the one absorbed is observed as transmitted light. If monochromatic light or a narrow band of radiation is used, the instrument is called a spectrophotometer.