Saturday, August 29, 2009

By the light of the moon

I've been out late a lot lately. I've done more night photography in the past couple months than I have in my entire career.

It's not that I'm changing my style or anything. Sometimes that's just how things work out.

In New Zealand, the middle of the night provided one of my only two opportunities to photograph Taranaki, a beautiful, perfectly conical volcano. The clouds were too thick the rest of the time I was there. And back home, a client needed an image of Comet Falls, which is located in Mount Rainier National Park. The waterfall gets its name from the fact it looks like a comet. Given that, why wouldn't I photograph it at night?

A lot of photographers struggle trying to figure out what exposure settings to use. Night photography doesn't make that process any easier.

Before I became a serious photographer, I assumed that taking a picture was an instantaneous process. You snap the button. The image is immediately recorded. Now, I realize there's more to it.

For something to be visible in an image, you need a certain amount of light. It's the same amount of light whether you're photographing at high noon or at midnight. The difference is how long you have to keep the camera's shutter open to allow enough light to accumulate. At noon, the capture is practically instantaneous. At night, you may need to keep the shutter open for hours.

Getting stars in your image only complicates matters more. When you look at the sky, it doesn't really appear as though the stars are moving. Take a picture of them and you quickly realize how fast the Earth is spinning.

I've found you need to use a shutter speed of no slower than 20 or 30 seconds to record the stars as individual points of light. Go much longer — even 30 seconds is starting to get a little long — and the stars start to blur. They — or actually the Earth — are moving that fast.

The problem is, 20 seconds may be too quick for the landscape below. Remember, the camera will only capture the land if you give it enough time to collect light. The darker it is, the more time it needs.

One way to solve this problem is to find something to light the land. Some photographers use powerful flashlights, guiding the beam back and forth over their subject while the stars shine in the dark. Some people call this technique "light painting." You use the light to paint the landscape. It works if you paint evenly. But you have to be careful. If you shine the light too much in one spot, it will be overly bright. If you miss a spot, it will be black.

I like to do my night photography around the full moon. The moon evenly lights the land, and, in most cases, is bright enough to allow you to photograph the land and the sky with one 20-30 second exposure.

You will need fast film or to boost your digital camera's ISO (simulated film speed), however. This Comet Falls image is a 20-second digital exposure taken at ISO 800.

This technique is almost foolproof. The only negative is the sky will likely be too bright to be able to photograph the Milky Way. The flashlight technique, of course, doesn't light the atmosphere the way the moon does.

(Check out more waterfall images at

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