TPE Web Orientation and Basics

Welcome to the first in a series of tutorials on how to use The Photographer’s Ephemeris Web.

Prefer to have something to print and read on paper? This article describes how you can create a PDF from any web page, including this tutorial.

The Photographer’s Ephemeris

TPE was inspired by a number of events during 2008: (i) a winter weekend workshop photographing at Dream Lake in Rocky Mountain National Park, which opened my eyes to how to plan landscape shoots using topographic maps, a compass, a protractor, and a calculator; (ii) returning to shoot Dream Lake a few months later and realizing I hadn’t planned properly; and (iii) heading up to Loch Vale, a much higher lake in Rocky Mountain National Park, for a shoot that was a total bust.

After all that hiking (and not many photos to show for it), I realized the importance of proper planning. I also reasoned that I would rather plan at my computer than purchase maps for every location I intended to visit. When I found no tools that combined all the right data or worked on a Mac, TPE was born.

TPE Web screen layout

Let’s start by taking a look at the basics of the screen layout.

The most important thing is the primary position marker: the red pin. You can drag this freely to exactly the point you need. All information generated within TPE is taken from the position of the red pin.

At the top left, the currently selected date is shown along with the time zone of the red pin position and the difference from GMT (Greenwich Mean Time). The elevation above sea level and the latitude/longitude of the current red pin position are also displayed.

You can change the selected date in the following ways:

• Using the calendar drop-down menu (up to 10 years before or after the selected date).
• Using the previous and next day buttons to change the date one day at a time.
• Using the Now button to move the selected time to your computer’s current time in the red pin’s time zone.
• Typing the desired date into the field, followed by pressing Enter/Return.

The right-hand sidebar contains most of the tools you’ll interact with regularly while using TPE. This includes the events timeline, which shows the day’s events: times and directions of sunrise, sunset, moonrise, and moonset (where they occur), twilight times, moon phase, lunar perigee and apogee, and new moon visibility information (read more about moon events).

At the bottom of the screen, the chart shows 24-hour sun and moon altitudes in graphic form. You can drag the time slider to adjust the time and see the azimuth and altitude information displayed numerically in the legend.

1. Primary (red) pin
2. Date/Event Selector, including current selected date
3. Latitude/longitude information for red pin location
4. Time zone information
5. Right-hand sidebar with Timeline
6. Altitude chart and time slider

Radiating out from the red pin on the map, you can see the azimuths (relative to true north) of sunrise (yellow line), sunset (orange line), moonrise (light blue), and moonset (dark blue). Using the previous and next day buttons, you can see the azimuth of an event change over time.

The thinner colored lines radiating out from the red pin correspond to the azimuth of the sun or moon at the time selected on the time slider at the bottom of the chart. Click and drag the time slider to see the azimuth and altitudes of the sun and moon change over the day.

Finding a different location

I’m guessing you’re probably not planning a shoot here, so let’s find somewhere else.

1. Click the search button above the map to display the Search window. Type the name of the place you’re searching for

We will recreate the trip I took in 2008, but for a date in 2021. Start by typing the name of the closest town, Estes Park, into the location text field.

Press Enter to begin the search, or click the search button adjacent to the text box. (If you’re a PRO subscriber, you’ll see results as you type.) The app will display matching results. Click the Go button for the first result to reposition the red pin to this location on the map.

You may wish to specify a county, state, or province as well as the town name in order to get the result you want. After all, there’s Paris and there’s Paris, Texas.

The new location

OK. Now we’re in Estes Park, Colorado, USA, near the east entrance to Rocky Mountain National Park. There are a few things to note:

• The elevation and latitude/longitude have been updated to reflect the new location.
• The red pin lies over the town of Estes Park.
• The time zone has changed to ‘America/Denver.’ TPE will automatically determine both the time zone and the daylight saving rules for any place and date you select.

1. Elevation and latitude/longitude of the primary (red) map pin
2. Time zone of the primary pin location
3. Primary pin

Moving into the park

Let’s assume we’re going to shoot sunrise at Dream Lake. You can manually pan around the map, zoom in and out, and drag the red pin to a precise position.

I’ve moved the red pin to the eastern shore of the lake, from which a photograph of Hallett Peak and Flattop Mountain can be composed.

Where will the light fall?

The yellow sunrise line terminates at the red pin position, but our subject lies to the west.

I’ve set the date for Monday, July 19, 2021. Look in the timeline and you can see that sunrise is at 5:49 AM. Clicking on this event in the timeline sets the selected time of day to that moment. Use the time slider to advance the time a couple of minutes (or click once on the slider and use your keyboard cursor keys to advance in ten-second increments).

The dark line overlaying the sun extension line is the sun shadow line. Advance the time slider to see this shadow line shorten as the sun gets higher in the sky.

Click the sunrise event in the timeline again to go back to sunrise and advance the time slider by a couple of minutes:

1. Sunrise time is shown in the timeline
2. Time slider is now set to 5:53 AM
3. Sun shadow line

On this date, it’s clear that the rising sun will come from the northeast, providing imperfect illumination of Dream Lake and the valley walls above – particularly the north side of the lake, which will be in shadow. Perhaps this is not the perfect time of year for the image…

Alternatively, in the above example, you could reposition the marker farther up the valley to see where the light comes from. There are other good reasons to take this approach too, which we’ll cover in a subsequent tutorial.

A better sunrise date for Dream Lake

Let’s skip a few weeks ahead to Sunday, September 12, 2021, using the date selector or advancing day by day using the Next Day button. As we adjust the time of day, we can see that the rising sun will illuminate the drainage above Dream Lake perfectly, providing the possibility of good light conditions.

The sunrise this time is 6:41 AM. Great news! That means you can also sleep in a bit longer and still make the shot.

1. Date selector
2. Next day button

Saving the location

Once you have a location identified, you may wish to save it for future use.

Click Locations in the left-hand navigation bar to view your saved locations. Click ‘+’ to save the current primary pin location:

1. Add primary pin position as a saved location

You can give a name to the saved location in the Title field and optionally enter some notes for future reference in the Notes field. Click Save to save your changes. You can also delete a saved location by clicking the Delete button.

1. Title field
2. Optionally, type notes for this location.
3. Click to delete
4. Click Save to save your changes

Note: Please use discretion when sharing photo location information.

That covers the basics. The same principles apply to any location you want to scout, including cities – for example, to determine when the full moon will rise along 42nd Street in Manhattan.