The latest release of The Photographer’s Ephemeris (TPE) releases even more tools to help us photographers get the shots we want. There is just too much for one article, so I am going to focus on a personal favorite subject – full moon photos.
Before handy apps like TPE, LightTrac and PhotoPills, figuring out where the moon might be on any given night took some educating. Pile on top of that the desire to know when the moon was behind, or next to, a specific feature, natural or man-made, and the calculations were beyond anyone lacking a degree in mathematics. But now, it’s all so much easier. Let me show you how I plan on getting a shot of the full moon behind Seattle’s Space Needle this May.
I’ll be using the iPad version of the app which allows for adding in a subject height. Nearly the same functionality is available with the Desktop and Android versions of the app, but the location of items may shift a little. With the desktop and Android version you will not be able to manually add in the subject height but can, using the Pythagorean theorem (and there are plenty apps for it), add in the angle you need.
To get started, I have decided I want to get a shot of the full moon behind Seattle’s Space Needle. It’s a subject that lends itself well to moon photos. I had a shot in mind that I later confirmed possible after viewing Tim Durkan’s fine example from last year.
Laying out the steps before I open the app, my process will look like this:
- Find a location where I can see the Space Needle, and one which faces mainly South or West (because of hills, I know shooting to the East is hard and the moon will not appear to the North of the Needle because of being in the Northern Hemisphere).
- Plot out my location and the location of the Space Needle.
- Account for elevation change and the height of the Needle.
- Let the program do its magic.
- Record my findings and make actual plans.
Finding your location
Loading the app brings up a fairly full featured screen.
To center the map on your intended location, simply move the map around with your finger until the crosshairs are over your location. You can then tap on the inside of the crosshairs or tap the red observer pin that looks like this:
I placed the location in a park near the shore of Lake Union, a place I know with good visibility of the Needle about 3/4 of a mile away. This will give me a good apparent size relationship of moon to Needle. Many locations can be scouted by using Google Street View.
Next, mark the location of the Space Needle. TPE has a decent search feature, you can use it to quickly find many natural and man-made features around the planet. Just click on the magnifying glass in the upper left and type Space Needle.
Now click the Space Needle entry itself and you’ll see three options appear.
In order from left to right, these buttons allow you to: center the map on the location as your primary location, set this location as your secondary location (the item you wish to photograph), and the third is an option to save this item as a favorite, making future recall easy without searching. You will want to click on the gray map pin to set the Space Needle as the secondary location.
Using geodetic information
To make things easier to see, click on the Google Terrain map set – an option on the right side of the screen that looks like this (image right)
Now the map is a little cleaner and after zooming out you can see the red pin where I’ll stand and the gray pin at the location of the Space Needle. Those orange and blue lines simply show location of the sun (orange) and moon (blue) when they rise, set and current location.
Notice that the lower display also changed? It now shows the elevation different between the two points, with distance (3,908 feet – can also be set to metric), bearing (213.4 degrees), elevation change (73 feet) and the angle at which you are looking, be it up or down (+1.7 degrees). There is also a nice plot between the points showing elevation differences.
This is great! But it only gives the elevation change at ground level. I need to add in the height of the Space Needle to position the moon properly. A quick wikipedia search tells me the Needle is 605 feet tall.
Click on the Shadow and Elevation tool at the top left of the screen, just to the right of the Search feature. Where it mentions “Secondary object height” put in 605 feet for the Space Needle.
Now on the elevation plot at the bottom of the screen there is a big white bar, representing the height of the Space Needle, on the far right. Perfect!
Now let’s have TPE do the heavy lifting and tell us when the moon will be perfectly behind the Space Needle, place the event on our calendar and go find other things to shoot!
Click on the Visual Search button, it is the one immediately to the right of the Search button on the top left. You will get a drop down that with all kinds of information. Click on the word “Moon” at the top and then “Full” and your screen will look like this:
The app has filled in the target altitude (14.1 degrees), compass azimuth or bearing (213.4 degrees), and tolerance (2 degrees) for us!
For a first run, to get a full moon centered over the top of the Space Needle, click on the Duration you would like (I picked 5 years in this example) and then Perform Search. You will see a list of results that look like this:
What does all that mumbo-jumbo mean? Quite simply, those are all the dates and times (and exact location of the full moon and how full it will be) that fall within a two degree margin of our requested position. You will notice the one at the bottom for August 16, 2019 has a green asterisk; this simply means the moon will be within .5 degrees of the request.
Clicking on the top item for May 4th, 2015 will make the map mimic the conditions at that exact time. Double tap the elevation profile at the bottom and it will show the Altitude Profile where you can see the full height of the Space Needle on the right (tall white bar) and the level of the moon in dotted blue.
All lined up! We’re now ready to save this information on our calendar or send it to a friend if we like. Click the share button on the upper right and you will see the option for adding to calendar as well as messaging, emailing, etc.
The location is set to the Primary Location in the app. You may want to adjust the time so you arrive early, as it defaults to the exact moment pictured in the app.
The email option includes all the pertinent information to share the details with a friend. It will attach a map and the recipient can open the information in the TPE (if they have it) or on the web browser version.
I left a lot of information out of this article because TPE simply has too many options to describe here. At its most basic though, it is excellent for placing the moon over various subjects.
All it takes is a quick Wikipedia search for an object’s height and about two minutes in TPE to plan that moon shot you have been dreaming of!
For those wishing to explore further, TPE’s documentation is fairly complete and worth the read to unlock a wealth of photo planning power.
How can you use this tool in your photography?
Table of contents
- Full Moon Photography Using The Photographer's Ephemeris 3.0
- ADVANCED GUIDES
- CREATIVE TECHNIQUES