How to take pictures of the moon

Almost every photographer at one time or another has taken a shot of the moon, either as the subject of the photo, or in the background of a photo. Taking the photo of a moon at night cab be more technically challenging that one thinks.

Did you know that the moon is 33,000 times brighter than the bright star Sirius? Inexperienced amateurs often believe that because they are taking a picture of the moon at night, they must use a long exposure, only to find that their result is a huge blob of glaring light. In fact, a full moon may only require a shutter speed of 1/250 second at ISO100. A waning or waxing moon will require slightly longer exposures because the quarter moon is only 1/10th as bright as a full moon.

The challenge in shooting the moon is revealing any sort of detail of the surface. The most intriguing features of the moon are its dark lava plains ("Mare") and the plethora of craters and mountains that cover its surface. While the full moon is most enchanting to the eye and soul while full, photographically-speaking it is the most boring! When the moon is full or near full, the surface reflectivity is at it highest and a lot of the fine details are lost. Only the brightest craters and darkest of mare will show up in your photos.

So what do you need to take really interesting, details photos of the moon?

Its possible to just go outside, put your camera on the "green box", point your 200mm lens at the moon and push the shutter release. But are you getting the most out of your camera? Most likely not. With a little more preparation you can really improve the quality of your moon photos.

The Requirements

• Tripod
• Remote shutter release
• Mirror Lock-up
• Patience

If you don't have a shutter release mechanism, MLU is your next best way to eliminate any sort of vibration. At high magnifications with a zoom lens, even the most minute vibrations can cause your image to blur and lose sharpness.

And thirdly, patience. With various lens, f-stop and ISO combinations possible, there is no one magic formula or camera setting that will work for all, especially considering how dynamic the moon can be. However, with a little patience you can quickly fine tune your settings to get a great photo of the moon.

Be aware of the phases of the moon

As I mentioned before, the full moon, while inspiring, is the least detailed of all the moons phases. Taking a photo any time before or after the full phase can yield subtle and exquisite detail you can't see with your naked eye. These are the details you want to bring out in your photo. But why is this? Why is a quarter moon more interesting than the full moon?

Its all about the sun angle. When the moon is full, the sun is essentially behind the earth, our vantage point. Light from the sun is illuminating features on the moon evenly and the light is reflecting right back towards us and the light source, so everything appears washed out and flat. With a non-full moon, especially a quarter moon or less, the sun angle is 90 degrees or more with respect to earth, so we see both shadows and highlights of features. Instead of flatly lit craters, we see their rims and shadows, mountains cast shadows and so on. A completely different landscape than a full moon.

The challenge now is that unlike the full moon, the surface of the moon now has a gradient of brightness. The sun-lit side is still extremely bright, yet there are details to be revealed along the "terminator", that line where light meets dark. Its takes some exposure experimentation to get just the right mix of the two to not blow out the lit side and overpower the details along the terminator.

Exposure

They key here is patience and bracketing. The first thing I'd do is use the camera's auto exposure to dial you in to an approximate shutter speed to base your tuning with. Set the AF-point to center, ISO to 100 and the camera on Av. The f-stop to use is up to you and your gear. If you're using good glass, you may be able to leave it at f/2.8, if its a mid-range zoom, you may want to set it to f/8. Once set, depress the shutter button halfway while putting the AF point on the brightest part of the moon. Make note of the shutter speed, you'll probably be working around that speed.

Set the camera to "M" and adjust the aperture to the same you used to test above, then dial in the shutter speed to slightly slower. Its probably OK to let the camera focus itself, if its having trouble, center the AF point along the bright edge of the moon, giving it a line to focus with. Take the shot! Playback the image, zoom in, see how it looks. Can you make out details of craters, rays and mare on the lit side? Are the crater details more visible on the terminator side? If its too bright and washed out, go with a faster shutter speed, if its not bright enough, set it a little slower. Experiment until you find the right shutter speed. A circular polarizer can help eliminate some of the lit-side glare and bring out some of the contrast of the mare as well.

The photo on the left was taken by me in April. Notice the detail of the craters at the top near the terminator, and the shadow inside the crater near the middle. These details would not be visible during the full moon. Each phase of the moon as it marches across the sky night after night yields new shadows on new features, so every night is different.

Earthshine

When the moon is between the new moon phase and the half-moon phase, there is a period where a very interesting effect can be observed. When you look at the moon in this phase, you'll notice that the dark side of the moon isn't fully dark and you can make out some details. This illumination of what should be the dark part of the moon is not lit by the sun but by the Earth! The sun's light is reflecting off the earth's clouds/water and slightly illuminating the rest of the moon visible to Earth. This is enhance by the fact that when the moon is slimmer, the Earth, as viewed from the moon, is more illuminated by the sun. (The Earth has phases when viewed from the Moon.)

With some patience, and some of the techniques outline above, you can bring out Earthshine with a camera. However, its almost certain that you will blowout the Sun-lit portion of the moon to accomplish this. But its yet another way to photograph the many moods of the moon.

In the image to the right, you can see details of the dark side of the moon while the sun-lit site is blown out. Another thing you can notice is the open cluster of stars known as the Pleiades, which the moon was very near to on April 1, 2006. With a slightly longer exposure, I brought out both the Earthshine and the stars, for a pleasing effect. A Larger Version is also available.

I hope you find this FAQ helpful with your own photos of the moon.