Glossary

D

Distance to the Horizon

Distance between a location (or a point on the Earth's surface) and the apparent line that separates earth from sky (horizon). Learn more on Wikipedia.

Day length

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.

Distance (sun, moon)

It is the distance between the sun or the moon and the Earth.

Depth of Field (DoF)

The distance between the farthest and nearest points which are in acceptable focus. This can also be identified as the zone of acceptable sharpness in front of and behind the subject to which the lens is focused on. Learn more on Wikipedia.

Depth of Field (DoF) Near Limit

Depth of Field near limit. Distance from where acceptable focus starts, when you focus at a given distance.

Depth of Field (DoF) Far Limit

Depth of Field far limit. The distance where acceptable focus ends, when you focus at a given distance.

Depth of Field (DoF) In Front

Distance between the DoF Near Limit and the focus plane.

Depth of Field (DoF) Behind

Distance between the focus plane and the DoF Far Limit.

Diagonal Angle of View

Angle of view measured  diagonally (from one corner of the frame to its opposite corner).

Diagonal Field of View

Field of view measured  diagonally (from one corner of the frame to its opposite corner).

Declination

The vertical angular distance between the center of a celestial body and the celestial equator. You can measure it using PhotoPills Night AR or PhotoPills Planner Night AR. 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.