The Photographer's Ephemeris®

Welcome to The Photographer's Ephemeris®, a Sun, Moon and Night photography planning tool for outdoor photographers.

Here's a quick guide to getting started with the app. You can find many more articles that cover features in more detail on our Help Center.

What can I use this app for?

TPE is tool for planning natural light and night photography. It is useful in any situation where your planned shot depends on the direction and quality of sunlight or moonlight, or the alignment of the Milky Way and stars. TPE is used by landscape and outdoor photographers around the world. Here are some examples of just some of the things it can help with:

When is the next "supermoon"?
When will the sun next rise aligned with a city street?
On what dates can I view the Milky Way to the southwest after the end of astronomical twilight?
Where is the closest area with low light polltion?
Is there a clear sightline to the top of a mountain from this point?
How long a shadow will this building cast at 4pm tomorrow?
Will I have a clear view of the full moon as it rises behind the city?
How many days after New Moon can I expect to first see the crescent?

As you become familiar with the app, you'll find many more situations in which TPE can help you plan to get the most from your natural light photography.

Basic Concepts

Here are a few basic concepts to help you get oriented quickly using TPE.

The Primary map pin shows the location for which the app makes its calculations. Sunrise, sunset, etc. are all calculated for this location - the lines you see on the map show the direction of the day's key events
By default the app opens in Day mode, which shows information about the sun and moon. Double tap the Timeline beneath the map to choose exactly what information is displayed
Planning night photography? Switch the app to Night mode by tapping the date at the top of the Map page. The moon, Milky Way and major stars and asterisms are displayed.
Select a date by tapping the date or using the Previous/Next buttons at the top of the page
Adjust the time of day by panning left or right on the Altitude chart: the altitude chart shows the angle of the sun, moon or galactic centre relative to the horizon
The map displays various controls, to control the map pins, map layers and displayed map type. Read more about Map Controls.

Finding a location

There are a number of ways to quickly find a location:

Drag/drop map pin: you can drag and drop the pin anywhere on the map: tap and hold then slowly move your finger to move the pin. Tapping the reticle at the center of the map will recenter the pin.
Track current location: tap this button on the map to have the app track to your device's current location.
Search by name: on the Locations page type a place name to search for matches on the web and in your saved locations list. Tap the red pin button to set the pin to the search result. Tap it again to have the map follow your device's current heading.

Finding a time or event

You can jump directly to a particular time or event:

Timeline events: tap any panel in the Timeline to jump to the indicated time. For example, you can jump directly to the start of Civil Twilight by tapping the corresponding panel
Celestial events: tap the Date at the top of the page to view a list of Celestial Events for the selected year. These include moon phases, solstices, lunar perigee (which includes "supermoon" dates), eclipses, meteor showers and more. Some events include additional information and web links.

Map types

TPE includes seven different map types.

Tap the map type selection button on the map to view available map types. Tap any of the displayed buttons to select a different type
In Settings, you can choose between Google and Apple for the map display.
With Google selected, available map types include: Standard, Satellite/Hybrid, Terrain, Open Street Map and Open Cycle Map Topographic
With Apple selected, available map types include: Standard and Satellite/Hybrid
In Settings, you can select between satellite and hybrid mode. Hybrid includes roads and placenames overlaid on the satellite map.

Learning more

As you get comfortable with the basics of TPE, there's lots more to uncover. Check out our Help Center posts on the following topics:.

Geodetics: point-to-point distance, elevation profile and sightline analysis
Augmented Reality: through-the-lens overlays of the sun, moon and stars for in situ shot planning
Visual Search: azimuth and altitude position search to find dates and times for specific sun/moon alignments
Shadows and Elevation: tools to determine shadow lengths cast by objects of a given height, and for manual elevation adjustments
Elevation at the Horizon: tools to determine distance to the horizon, dip of the horizon and to adjust rise and set times for cases where the observer is elevated above the horizon (e.g. sunrise on a mountain summit)

Help Center

If you'd like to read more about TPE, please check out the articles in the Help Center, which explain some of the more intermediate and advanced features of the app:

Help Center articles are available in English.