Tuesday Jul 28, 2009 at 23:51

Using TPE, Part 1: the basics

Welcome to the first in what’s intended to be a short series of tutorials on how to use The Photographer’s Ephemeris.

TPE was inspired by a number of events during 2008: (i) a winter weekend workshop in Rocky Mountain National Park with Glen Randall which opened my eyes to how plan landscape shoots – topographic maps, compass, protractor and calculator; (ii) going to shoot Dream Lake once again a few months later, and realizing I hadn’t planned properly and (iii) heading up to Loch Vale last November for a shoot that was a total bust. After all that, I realized that I while I wanted to improve my planning, I’d rather do it at my computer. Finding no tools that combined all the right data or which worked on a Mac, TPE was born.

This tutorial is based on Beta 0.9.5. Click on a screenshot for a full-size expanded view.

The screen layout

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

1. The elevation above sea level and latitude/longitude of the current location is shown above the map
2. The most important thing of all: the primary position marker. You can drag this freely to exactly the point you need
3. The time zone of the current location and difference from UTC (universal coordinated time – effectively the same as GMT)
4. The current selected date is displayed along with times and directions of sunrise, sunset, moonrise and moonset (where they occur)
5. You can change the selected date using the previous and next day buttons
6. Alternatively, select an arbitrary date (past or future) from the date control

You can see that the directions of sunrise, sunset and moonrise are shown on the map. (There is no moonrise on this date at this location.) The map legend can be toggled on or off – once you are familiar with the standard colours (which can be customized), you may wish to hide the Legend to declutter the map.

Rise/set information is shown for days before and after the selected day, allowing the optimal day for a shoot to be selected. This is particularly useful for moon images, given that the timing, azimuth and phase of the moon varies significantly from day to day.

Finding a different location

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

Click in the search text box below the map (highlighted above) and type the name of the place you are searching for. Press enter to begin the search, or click the search button adjacent to the text box (magnifying glass). Google Maps will find the closest match to the specified location and reposition the map and the primary map marker to that place.

Where possible, specify a county, state or county name in addition to the town name, in order to ensure the best match. 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:

Notice that the elevation and lat/long are updated reflecting the new location. The map marker lies over the town of Estes Park. Additionally, the time zone has changed to ‘America/Denver (MDT)’. TPE will automatically determine both time zone and daylight saving rule for any place and date you select.

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 primary marker to a precise location.

The marker is positioned on the eastern shore of the lake, from where a photograph of Hallett Peak and Flattop Mountain may be composed.

Where will the light fall?

The lighter orange sunrise line terminates at the marker location, but our subject lies to the west. Holding down the Shift key will cause the rise/set lines to extend through the marker location, showing how the light will fall:

It’s clear that in late July, the rising sun will come from the north providing imperfect illumination of Dream Lake and and the valley walls above. 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 date

Skipping a few weeks ahead to mid-September, using the date control, and holding down Shift once more, we can see that the rising sun will illuminate the drainage above Dream Lake perfectly, providing the possibility of good light conditions:

Note from the sunrise time on the right, that you can also have a slightly longer lie-in and still make the shot.

Saving the location

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

Click the Locations link button on the top right, click the add button (+) and type a name for the entry. The program will automatically look-up a default name based on the nearest known place name. You can configure the default format for the placename in the configuration options page. Alternatively, press Shift + to add a new Location.

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

In the next tutorial, we’ll look at some of the other information available in TPE, including twilight times and the Details view.

You might also enjoy “Understanding Light with The Photographer’s Ephemeris” co-authored with renowned landscape photographer Bruce Percy. It’s available through Bruce’s web-site

Posted in TPE Technique

Stephen · Tuesday, July 28, 2009, 23:51 · Permalink

39 comments on this post