Move the date. Earth’s orbital position on the left and the Sun arc seen by a ground observer on the right update together. Hover a knowledge point on desktop, or tap it on mobile, for the deeper explanation.
The main cause is Earth’s rotation. A ground observer rotates eastward with Earth, so the Sun’s local hour angle changes continuously and creates the familiar daily sweep across the sky.
Orbit alone would not create strong seasons. The key is Earth’s ~23.44° axial tilt. Because the axis keeps nearly the same direction in space, the subsolar point moves between the tropics and solar declination changes.
At northern mid-latitudes, positive solar declination brings sunrise farther northeast, sunset farther northwest and a higher noon Sun. The arc therefore stays above the horizon longer. Winter reverses this pattern.
From the same shooting position toward the same landmark, the sunset point moves along the horizon through the year. The rotating sunset line in the main map is this geometry applied directly to scouting.
Solar declination changes altitude, sunrise and sunset bearings, daylight length and shadow direction together. Use the model to choose the season and direction, then verify the exact local event in Viewer or Planner.
Choose the visual goal first: a low warm Sun near the horizon, a higher Sun for stronger direct illumination, or twilight after sunset. Exposure cannot be fixed from geometry alone; start by protecting highlights and meter the actual sky and foreground.
At the same location, sunset and sunrise bearings shift through the year. Move the date until the solar path approaches your foreground direction, then use Planner to test whether the line actually crosses the landmark from a reachable camera position.
Arrive before the target light. Small changes in camera position can move a foreground edge across the Sun, while a few minutes can change altitude and shadow length substantially near the horizon.
Check solar altitude, azimuth, foreground clearance, cloud near the horizon, and highlight clipping. Near sunrise or sunset, atmospheric extinction and refraction can make the real disk look dimmer, redder or slightly displaced from a simple geometric expectation.
Do not assume the Sun sets due west every day, or that “golden hour” has one universal clock duration. Its photographic look depends on solar altitude, atmosphere, terrain and latitude; the geometric path is the planning backbone, not a brightness guarantee.
Plan a foreground alignment · Check sunrise/sunset now · Understand twilight · Handle contrast
Choose one landmark bearing, then move the date from a solstice toward an equinox. Find when sunrise or sunset comes closest to that bearing, and verify the candidate date in Planner rather than assuming the seasonal model alone guarantees visibility.
Seasonal geometry is grounded in NASA explanations of Earth’s axial tilt and orbit. Sunrise/sunset terminology, azimuth/elevation and atmospheric-refraction limits follow the NOAA Solar Calculator documentation. NASA Earth facts · NOAA Solar Calculator glossary
This 3D lesson is a teaching model, not a local visibility forecast. Viewer and Planner calculate event geometry separately; terrain, buildings, clouds, aerosols and exact local refraction can change what you actually see and photograph.
This compares mean diameters at a true size ratio, not distances: Sun ≈ 109.2 Earths and Moon ≈ 0.273 Earths. Also keep two different angles separate: Earth’s axis is tilted about 23.44°, while the Moon’s orbit is inclined about 5.145° to the ecliptic.
Mean diameters: Sun ≈ 1,392,700 km · Earth ≈ 12,742 km · Moon ≈ 3,475 km. The diagrams preserve diameter ratios; orbital distances are compressed separately.
