The number of daylight hours per day. Refers to the time measured from the moment the upper limb of the sun's disk appears above the horizon during sunrise to the moment when the upper limb disappears below the horizon during sunset. Learn more on Wikipedia.
It corresponds to the area of acceptable sharpness in front of and behind the subject to which the lens is focused on. Learn more on Wikipedia.
Distance from where acceptable focus starts, when you focus at a given distance.
The distance where acceptable focus ends, when you focus at a given distance.
Distance between the DoF Near Limit and the focus plane.
Distance between the focus plane and the DoF Far Limit.
The vertical angular distance between the center of a celestial body and the celestial equator. A declination of +20° means that the celestial body is located 20° north of the celestial equator. The south polar cap is at a declination of –90°, the equator is at declination 0°, and the north polar cap is at a declination of +90°. Declination is to a celestial globe as latitude is to a terrestrial globe, a vertical positioning of an object. Learn more on Wikipedia.