Few things in nature inspire our gasp-and-point reflex more than a thin slice of moon floating in the soft color separating day and night. While the moon’s appearance in the midst of our daily travels may appear random, its phase and position can in fact be known with surgical precision for every second of every day at every location. And none of this is a secret, which means adding a crescent moon to your favorite landscapes is a simple matter of doing a little homework, arming yourself with basic photography skill, and making the effort to get out there. (And you don’t need a camera to enjoy it.)
Phase dance: Lunar geometry 101 (this won’t be on the test)
Most people know the that the moon orbits earth (roughly) every four weeks, and its phase is determined by the alignment of the sun, earth, and moon. If you can picture the changing relationship between earth, the moon, and the sun as the moon circles earth, it’s a logical step to understand the correlation between the moon’s phase, and rise and set times. (But if this kind of geometry causes your eyes to glaze, feel free to skip to the next section.)
Mentally draw an infinite line connecting the sun and earth and continuing beyond earth into space. The half of earth on the entry point of that line is in daylight; the half of earth on the side where the line exits is night. The orbiting moon crosses that connecting line twice each month, once passing between earth and the sun, and again (about) two weeks later, behind earth. When the moon, earth, and sun are aligned earth in the middle (sun—>earth—>moon), all of the bright side of the moon faces the dark side of earth, and we see a full moon; when the moon is between the sun and earth (sun—>moon—>earth), the moon’s dark side faces earth’s daylight side and we see no moon (we call this the “new moon”).
Go back to the full moon scenario (sun->earth->moon): In the 24 hours earth takes to complete a single rotation, just as earth rotates from day to night (sunset), the sun disappears in the west and the full moon rises in the east, ascends until about midnight, then drops and disappears beneath the west horizon as the sun reappears in the east. In other words, a full moon always rises in the east at sunset and sets in the west at sunrise, and is in the sky all night long. (Any noticeable deviation from this is the result of terrain blocking the horizon, extreme latitude, and/or an offset in the actual instant of lunar fullness.)
Now return to your sun/earth line and imagine the new moon scenario (sun->moon->earth). While you won’t see the moon at all when it’s perfectly aligned between the sun and earth, skew the moon just slightly from its alignment with the sun and earth (a day or two before or after it’s new), when most of our view of the moon is dark, we still get a brief glimpse of a sliver of illumination just before light from the rising sun washes it out (an “old” moon), and just before it follows the setting sun beneath the horizon (right after the new moon).
If all of this is too much to absorb, just remember that the duration of the moon’s appearance in our night sky is a function of amount of the moon’s disk we see: a full moon is visible all night; a crescent moon is only visible for a relatively short time just before or just after sunset.
Figuring out when and where will the crescent moon appear
To photograph a crescent moon low on the eastern horizon, you need to be on location an hour or so before sunrise a day or two before the start of the new moon (remember, the official new moon isn’t visible at all because its unlit side rises and sets with the sun); photographing a crescent low in the west requires being on location at sunset at day or two after the new moon and waiting for the sky to darken enough for the moon to be visible. But when will that be?
There are many resources for tracking the moon’s phase and location. The U.S. Naval Observatory is chock full of useful information, more than you’ll probably ever need; this was my prime resource in my pre-iPhone days. But as far as I’m concerned, you just can’t beat the anytime access to data smartphone apps provide.
Rather than list every smartphone app (that could take days, and would surely be incomplete), I’ll just give you a couple with which I have direct experience. My primary app is Focalware. I like Focalware because it’s straightforward, and it gives me the sun/moon info I need for any location on earth, without wifi or cell service (very important to someone who spends as much time “off the grid” as I do). With Focalware, I can choose from a fairly comprehensive list of pre-programmed locations, input my own by providing latitude and longitude, or simply save my current location.
Another great app is The Photographer’s Ephemeris (TPE)—more complete and interactive than Focalware, but because it uses Google Maps, it’s much slower and requires good connectivity. There’s also a quite comprehensive, free, Mac or Windows version of TPE, that I’d probably use when I’m not on the road if my sun/moon workflow weren’t already long established. And again, there may be other apps that are just as good or better, but these are the ones I know. And I’ve recently started playing with Photo Pills, which has the potential to be even more useful than TPE.
Choosing your subject
The key to photographing a crescent moon is understanding that, because the moon in its crescent phase is always in the general direction of the sun, it’s also in the brightest part of the sky while the rest of the scene is in pre-sunrise or post-sunset shadow. Since a camera can’t capture the range of light you or I can see, any non-reflective, unlit subject or surface sharing your frame with a correctly exposed crescent moon will photograph quite dark to completely black.
So what subjects do work? I thought you’d never ask. My go-to crescent moon subjects are water and silhouettes. Water because it reflects the color from the sky; silhouettes because their outline stands out against the colorful sky. And a combination of both is even better.
The water you choose doesn’t need to be special (remember, whatever’s around it will likely be black anyway). Unless you live in a desert, I’m sure you can think of a nearby lake, river, stream, or pond. The key is to turn off the way you see the water and remember that you’re simply photographing its color (reflected from the sky) and outline. For added interest, you can also compose silhouettes of rocks and trees against the water.
Silhouettes are all about shape. Yosemite is great because pretty much everything there towers above you and is (relatively) easy to isolate against the sky. But you don’t need to go to Yosemite for silhouettes—think about the geology in your region that you can get beneath and shoot up on.
Trees make great silhouettes, and just about every region has its distinctive trees. Here in California we have lots of rolling hills with oak trees just made for sunrise/sunset silhouettes. In Hawaii, monkeypod trees create sweeping canopies of serpentine branches that tower over the landscape, and palm trees are both distinctive and ubiquitous. And who doesn’t enjoy the classic Serengeti acacia silhouette? Nothing quite so exotic near you? Just find a large tree that stands alone. Groups of pines jutting skyward also work well.
A few words about composition
When composing a crescent moon, photograph the foreground as your camera sees it, not as you see it. While you can likely still see detail in the foreground, your camera can’t—including too much foreground just because you can see the detail there will result in a large, empty (black) area in your image.
A crescent moon image is primarily about the sky, so commit most of your image real estate to the sky: If you’re photographing a silhouette, give the composition just enough foreground to hold the shape you’re silhouetting. And since everything that’s not lit will be black anyway, underexposing slightly will enhance the natural color without any real cost to the rest of your composition.
To overcome the moon’s tendency to appear much smaller in your frame than you perceive it in person, position yourself as far from your foreground subject as possible, then use as much telephoto as your position allows. This approach leverages telephoto compression, which draws the background closer to the foreground. When a wide angle lens makes the moon tiny in your frame, don’t despair. A moon carries extreme “visual weight” that allows it to carry a large portion of an otherwise empty area of your frame.
I find attempting to photograph silhouettes in anything but manual exposure mode is too much effort because your camera’s auto mode will have no idea that you want that tree black. You could override this inclination with exposure compensation, or you could just learn manual exposure (it’s not hard).
When I photograph a crescent moon, I start by determining my aperture (usually f/8 – f/11, because that’s where my lenses tend to be sharpest and depth of field is rarely a consideration in a silhouette image), spot meter on the brightest part of the sky, dial my shutter speed to 0 to +1 (above middle tone), then check my result and adjust to taste. Once I get the exposure right, the only adjustment necessary is to account for the increasing or decreasing light.
If you’re like me, daily life sometimes overshadows photogenic celestial events, so I suggest that once you do determine the date for the moon phase you want to photograph, put it in your calendar. And always be on the lookout for potential crescent moon subjects—I have a mental database of potential subjects, both local and distant. When things are slow, I go through them and figure out when the moon will be best aligned for photography. If I come up with something good, that goes in my calendar too.
In photography it’s almost always better to be much too early than just a little too late. Not only does arriving early protect you from missing the best stuff, it also allows you time to familiarize yourself with the scene and plan your compositions. And if you’re really adventuresome, show up a few hours before the sunrise moonrise, or stay out past the sunset moonset. Without the moon to wash out the sky, a moonless night is filled with stars (ideally, you’ll be a good distance from city light pollution). The subjects that work for a crescent moon are also good for starlight. For more about night photography, read my Starlight page.