Track the sun over real terrain in 3D and AR

How do you read a 3D sun path?

Read the arc as a sequence of sun positions. The direction tells you which side the light comes from; the height tells you whether it clears the skyline.

Direction / azimuth

The compass bearing of the sun. It helps you anticipate front light, side light or backlight relative to your camera.

Height / altitude

The sun’s angle above the horizontal. Low light makes longer shadows; high sun reaches over more obstacles.

The terrain skyline

The outline of the surrounding ground seen from the pin. A mountain can hide the sun after published sunrise or before sunset.

Explore the Yosemite animation → Sunrise moves automatically to the ridge clearing. Scroll once to last light, then scroll again to explore the app.

When does sunlight reach Tunnel View in Yosemite?

At our Tunnel View pin on 21 June 2027, the calculated direct-sun intervals are 06:27–18:15 PDT. Flat-horizon sunrise and sunset are 05:37–20:24 PDT.

Location

Tunnel View, Yosemite National Park, California, USA

Pin

37.7156°, -119.6767°

Time zone

America/Los_Angeles; PDT in March and June, PST in December

Terrain

2 m USGS 3DEP ground within 2 km; 40 m terrain beyond

Calculated from Sunreach’s published engine dataset. Estimated terrain timing accuracy: ±1 minute, with additional atmospheric uncertainty near the horizon. These are clear-sky ground-model estimates, not observations or a weather forecast. Trees, buildings and changes since the survey are not included in this example.

The pin represents a person standing at the viewpoint. It does not represent the light on El Capitan, Half Dome or Bridalveil Fall. Read the El Capitan sun and shade guide for a separate subject calculation.

How do you plan a photograph with terrain and sunlight?

1. Choose your camera position and date. Small moves can change the nearby skyline; winter and summer take different paths.
2. Check when the pin receives direct sun. Compare it with sunrise, sunset and the golden-hour windows. They need not overlap.
3. Inspect the direction in 3D. Look at how the sun sits relative to your subject and where the surrounding terrain casts shade.
4. Check the subject separately, then the weather. A shaded viewpoint can face a sunlit peak. Allow time for access and setup before the light arrives.

For a trip, use the same approach for a lakeside lunch, a terrace or a winter valley walk. See how to plan a mountain trip around the sun and why golden hour can miss a mountain viewpoint.

How does the AR sun tracker work on location?

AR overlays the sun’s path and the terrain skyline on your live camera view. It shows where the sun will be relative to the landscape in front of you, using your current location.

Use the 3D eye-level view to preview a remote viewpoint before you travel. AR uses your iPhone or iPad camera where you are standing and lines itself up on the sun or the skyline. The browser demo shows the 3D terrain view. See how the two views work together →

How accurate is the 3D preview?

The homepage is an illustration of the day, with simplified terrain and a moving camera. Its displayed times come from a separate, higher-resolution skyline calculation.

The homepage’s terrain is sampled at 40 m and drawn at 80 m. The Tunnel View sunlight calculation uses a 2 m ground model nearby. Fine trees, overhangs and narrow features may be missing; terrain resolution is not a guarantee of photographic conditions.

The app reports the terrain source and estimated timing accuracy. Global 40 m terrain has an estimated ±5-minute timing accuracy; 2 m lidar has an estimated ±1-minute accuracy, with additional refraction uncertainty when the sun is low. Coverage varies by location. See definitions, data sources and accuracy.