Photographing the Lunar Eclipse

A lunar eclipse occurs when the sun, Earth, and moon line up so that the Earth’s shadow falls on the moon, darkening it and producing a “rusty” color which is why some people call this a “Blood Moon”. This is caused, for those light nerds out there, by refraction of sunlight by the Earth’s atmosphere. This is why photographing the lunar eclipse is a bucket list item for many photographers.

Here to give us some tips on how to that is Michael Frye, a professional photographer who specializes in landscapes and nature with plenty of experience shooting the lunar eclipse.

Michael’s photographs and articles about photographic art and technique have appeared in publications around the world, and he is the author and/or principal photographer of four books: The Photographer’s Guide to Yosemite, Yosemite Meditations, Yosemite Meditations for Women, and Digital Landscape Photography: In the Footsteps of Ansel Adams and the Great Masters.

Photographing the Lunar Eclipse

by Michael Frye

I’ve photographed several lunar eclipses and they’re spectacular events to view and photograph. But photographing at night presents challenges. How do you focus in the dark? How do you get the right exposure? To help speed your learning curve, here are my best tips for making your own lunar eclipse photographs:

Equipment Needed for a Photographing the Lunar Eclipse

• DSLR or mirrorless camera with full manual exposure control. Test your mirrorless camera first to make sure you can focus and compose in the dark with the electronic viewfinder (see Focusing below).
• At least two fully charged camera batteries.
• Sturdy tripod.
• Cable release, electronic release, or remote.
• Interval timer or watch.
• Flashlight or headlamp.

Moon Position of the Lunar Eclipse

Finding a good location means first moving away from cities to avoid light pollution. If you live on the east coast, you’ll need a clear view to the southwest while west coast viewers will be looking almost directly south.

To calculate the moon’s position accurately – if you want to line it up with a building or mountain, for example – there are several excellent apps available. The Photographer’s Ephemeris (for iOS or Android) is one of the best. PhotoPills has similar tools, plus an Augmented Reality feature for visualizing the path of the moon against a live picture of the scene in front of you.

When the partial eclipse begins the moon will become a smaller and smaller crescent as the Earth’s shadow seems to take a bite out of the moon. During the total eclipse, the moon will look much dimmer and turn orange or even red-orange in color. Just after the total eclipse the moon will return to a slender crescent and then get larger and larger until the eclipse ends and the moon becomes completely full again.

Focusing for the Lunar Eclipse

Since most modern lenses focus past infinity, you can’t just crank the focusing ring all the way to the end and expect to get sharp photographs. The most accurate way to focus in the dark, by far, is to use live view, zoom in on the moon, and focus manually. It may help to crank up the ISO for this. Autofocusing on the moon should also work if the moon is bright enough (like before the total eclipse begins) – but be sure to then turn autofocus off so that the camera doesn’t accidentally focus on something else.

Exposure Settings to Use for Your First Lunar Eclipse

Light meters are useless for getting good exposures of the moon because even a one-degree spot meter can’t read just the moon but will also include some of the surrounding black sky. So here are some suggestions based on past experience, including making the photographs you see in this post. You’ll need to use manual exposure mode and check your camera’s highlight alert (the “blinkies”) to make sure you’re not overexposing the moon:

• Full moon, or moon more than half visible: 1/60 sec. at f/11, 200 ISO
• Half to one-quarter of the moon visible: 1/30 sec. at f/11, 200 ISO
• Less than one-quarter of the moon visible: 1/15 sec. at f/11, 200 ISO
• Just the edge of the moon lit: 1 sec. at f/11, 200 ISO
• Fully eclipsed at the beginning and end of totality: 8 sec. at f/11, 800 ISO
• Fully eclipsed, deepest totality: 8 sec. at f/11, 1600 ISO

In the examples you see in this post, I’ve kept the aperture constant at f/11, but if you need more depth-of-field you could use f/16 and either double the ISO or the length of the exposure. You want to keep the exposures relatively short, otherwise the moon will move and blur. You can get away with eight or maybe even fifteen seconds with a wide-angle lens, but with a telephoto lens you need to use shutter speeds of four seconds or less. To find the maximum exposure time for your lens before movement appears, divide the focal length into 400. So 400 ÷ 25mm = 16 seconds, or 400 ÷ 100mm = 4 seconds. Bracketing exposures is a good idea.

Oak tree and lunar eclipse sequence, December 10, 2011, Sierra foothills, California. ©Michael Frye

Eclipse Shooting Strategies

Trying to include a foreground makes things more complicated, so the simplest way to photograph a lunar eclipse is to take a long lens and zoom in on the moon. If you photograph the eclipse from beginning to end you can even use Photoshop to assemble your images into a montage showing the whole sequence.

A more evocative approach – but a more complicated one – is to capture the eclipse sequence with a foreground, as I did in the photographs in this post. To do this you’ll first need to figure out the exact path the moon will take so you can compose your photograph accordingly. The apps I mentioned above, PhotoPills and The Photographer’s Ephemeris, are invaluable for this.

Once you’ve composed, make sure your tripod is solidly planted and locked tightly. You’ll want to focus on the foreground, not the moon, and use a small enough aperture to get both foreground and moon in focus. A bright flashlight and live view are helpful for focusing on the foreground.

Then make a series of exposures to capture the eclipse sequence. In the two photographs included in this post, the interval was ten minutes between each moon capture, but you could make it fifteen or twenty minutes if you want to space the moons farther apart. Just make sure you keep the interval the same throughout the sequence. You can use an interval timer for this or just use a watch and trip the shutter manually (using a remote or cable release, of course). You’ll need to adjust the exposure times (and possibly the aperture or ISO as well) as the moon dims and brightens.

In my photographs I used electronic flash or a flashlight to light-paint the trees in between making exposures of the moon. Light painting is a complex subject that I won’t get into here and, if this is the first time you’ve ever tried photographing an eclipse, I’d suggest you keep it simple and don’t try light painting. Just try to capture single images of the moon itself, or perhaps a sequence with silhouetted trees or other objects in the foreground.

Lunar eclipse sequence, August 28, 2007, Yosemite National Park, California. ©Michael Frye

Assembling a Sequence of Your Lunar Eclipse

If you get ambitious and try a sequence, the final step is to assemble the images in Photoshop. From Lightroom you can select the images and choose Photo > Edit In > Open as Layers in Photoshop, and Photoshop will stack the images into one document as separate layers. Or you can do this by hand using the Move tool to drag one image on top of another; just make sure you hold down the shift key while dragging so that the images align properly.

Then change the blending mode of every layer except the bottom one to Lighten. This makes light areas override dark areas, so the moon from one frame will override dark sky from another frame. As you do this you’ll see all the moons magically appear and complete your sequence. If you light-painted a tree or other object, that too will appear when you change the blending mode for that layer. If you used a telephoto lens to capture the whole eclipse sequence, you can use the Move tool to drag each layer around and arrange the moons on your canvas.

Photographing a lunar eclipse takes planning and a willingness to lose some sleep but it can be a tremendously rewarding experience.