Have you ever seen a photograph of a waterfall with the water appearing silky smooth and wondered how that effect is achieved? In this tip I shall reveal how.
The latest in my series of sixty-second tips is going to tackle one of the most popular effects in photography – often used in landscape and urban photography.
The effect in question is created by a long exposure. In other words, an intentionally long shutter speed that can range from a couple of seconds to minutes or even hours.
What’s happening?
The longer the camera shutter is open, the more light and motion there is being captured on the sensor.
Therefore instead of the flow of water being captured in a fraction of a second, it is being captured over, say, several seconds – meaning all the motion during that time will be registered, resulting in a smooth, blurred effect.
With a sufficiently long exposure you can make even the choppiest of seas look like polished glass.
So I just set a slow shutter speed?
That’s partly it. Don’t forget that using a slower shutter speed means letting in more light. If you are taking a photograph of that waterfall in bright daylight, using a slow shutter speed will likely cause the image to be overexposed because too much light has been captured.
If you are shooting it at dusk or dawn, when there is less daylight, it likely won’t be a problem because there is not enough ambient light around to affect the exposure.
And don’t forget: a tripod is essential in order to keep everything steady.
So how do I achieve long-exposures when there is too much ambient light?
That is the question! And the answer is to use a neutral density filter.
I won’t get technical here but an ND filter is essentially a dark piece of glass that you place in front of the lens to trick the camera into thinking there is less light available than there really is.
So even at midday, with a sufficiently dark ND filter you should be able to shoot a 30s exposure of that waterfall and because the ND filter is reducing the total amount of light entering the camera, your image won’t be overexposed.
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Enjoying these sixty-second tips? Click here to read more posts in this series covering topics like focal length, ISO, depth of field, and more.