Moon shots

Last Monday we experienced what’s called a “supermoon.” It’s when the moon comes closest to Earth in its elliptical orbit (its perigee) appearing up to 14% bigger and 30% brighter than when it is at its furthest point (apogee). It occurs, on average, once every 14 months, though there are some long periods without one and others where it may happen several months in a row.

For those wanting to photograph the moon, it’s about a quarter million miles away and takes up only a small percentage of the night sky, so you’ll need a telephoto lens if you want any kind of close up photo of it. I’d say something in the 300mm range at minimum.

Exposing for a full moon is relatively straightforward and simple. Many people think that, because the moon comes out when it’s dark, photographing it is a difficult thing requiring a tripod and long time exposures. But that’s not the case.

The light that falls on the moon is essentially the same as it would here on earth during the day (eg: 1/500th of a second at f/11 at ISO 400). So photographing the moon as if you were taking a daytime picture in your backyard or down the street, exposure-wise, is about the same. You may think that the additional distance the moon is from the sun would make a difference, but in astronomical terms that distance is negligible.

There are some atmospheric conditions that may alter your exposures, though. If it’s cloudy, foggy or there’s pollution in the air, then those things may cut out light coming from the moon and you’ll have to adjust your exposures accordingly.

There is an “either-or” when exposing shooting the moon. Either you have to expose for the moon or you have to expose for the surroundings on the ground. It’s up to you to figure out what’s more important to you.

If you want detail in the moon then you’ll need to use the aforementioned daytime exposure. That means you’ll be able to see the man-in-the-moon features of the orb, but anything like people, trees or buildings in the foreground will be greatly under exposed and appear black as, well, as night. You could get something or someone silhouetted if you positioned them in front of the moon but you won’t get any detail in them.

On the other hand, if you want those foreground to be seen then you’ll have to expose for the surrounding area. Since it will most likely be very dark, you’ll probably be using a timed exposure measured in full seconds or even minutes and a tripod to hold the camera still. This will allow you to see the foreground but, here’s the trade-off, the moon will be an overexposed glowing ball of white light.

There are 2 exceptions to theses rules. First, if it’s a cloudy night you might be able to block out just enough of the light coming from the moon to balance it and foreground. But it has to be the right amount of cloud cover. Too much and you’ll block out the moon completely, too little and you’re stuck with your original problem.

Secondly, during the hours of dawn and dusk there is a short time where the moon, sky and foreground are all about the same exposure. It’s a delicate balance that’s struck as the moon either rises or sets. The rising or waning ambient light of the surround area and the thickness of the atmosphere that the moon’s light has to travel through while down near the horizon helps bring the two exposures closer together.

The difficulty here is one of timing. Moonrises and moonsets occur at different times and not always during the dawn/dusk hours so you’ll have to research those times to know when they happen. Also the length of this period is very short lasting at times only minutes before the exposure window is closed so you’ll have to shoot quickly.

December 14, will mark the last of 3 consecutive supermoons of 2016. The next one after that will occur on Dec. 3, 2017. So you’ll have one more chance this year to get out and shoot the moon.

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