The vertical angular distance between a celestial body (sun, moon, ...) and the observer's local horizon. For visible objects it is an angle between 0 degrees to 90 degrees. For example, the elevation of the sun is the angle between the direction of the geometric center of the sun's apparent disk and the observer's (idealized) horizon. We say sun is at elevation 12º when it is situated at 12º above our ideal horizon. Learn more on Wikipedia.

Elevation error

When looking for dates and times the sun or moon will be in a desired position, the error of the azimuth and elevation define the spatial region we consider results to be acceptable. By introducing a margin of maneuver when setting the desired sun or moon's position (azimuth, elevation), likelihood of getting a result increases. To sum up, the Planner will give us any date and time sun or moon will be at: (azimuth+-error, elevation+-error). For example if we are looking for dates when the moon is at azimuth 93º and elevation 10º and we accept a 3º azimuth error and 2º elevation error. We will get as a result  all dates in which the moon's azimuth will be in the interval (90º,96º) and the moon's elevation will be in the interval (8º,12º).


Occurs twice a year (around 20 March and 22 September), when the tilt of the Earth's axis is inclined neither away from nor towards the sun, the center of the sun being in the same plane as the Earth's equator. Learn more on Wikipedia.


The amount of light allowed to fall on each area unit of a photographic medium (photographic film or image sensor) during the process of taking a photograph. Learn more on Wikipedia.

Exposure Value (EV)

A number representing equivalent shutter speeds and lens apertures combinations for the same exposure, given a scene brightness. At ISO 100, 0 represents (f/1.0 at 1 sec); 1 = (f/1.4 at 1 sec) or (f/1.0 at 1/2 sec); 2 = (f/2.0 at 1 sec) or (f/1.4 at 1/2 sec) or (f/1.0 at 1/4 sec) and so on. Learn more on Wikipedia.


Exposure value at ISO 100.

Event Duration (Time lapse)

Total time of the event for which you want to create a time-lapse video.