Photography News 05



Camera class

Everyone has to start somewhere, even top pros, and in our regular Photo School feature we’ll be taking a close look at core techniques that every beginner needs to know. This month, in Camera Class we look at how you can use shutter speed creatively, while Software skills (opposite) looks more at enhancing your images in Adobe Lightroom

painting or waterfalls, for example. Again, the exact shutter speed you need depends on the effect you want to create and how much movement there is. Most cameras let you set shutter speeds of up to 30 seconds, but you can go beyond this too – in Bulb mode, the shutter stays open for as long as the shutter release is held down. For long shutter speeds, it’s important to mount the camera on a sturdy tripod so the only movement is of the subject, not the camera. If you’re using a very long exposure, you might find you can’t close the aperture enough to avoid overexposure, or indeed you might want to keep the aperture wide open for a shallower depth-of-field. In either case, you can use a neutral density filter in front of the lens to block some light. Different filter densities are available. The densest is a ten-stop filter, which hugely increases exposure times – for example, it turns a shutter speed of one second into more than 17 minutes. These filters are popular for blurring the movement of water. n  How can I achieve long exposures without overexposing?

shutter speed as slow as 1/60sec or even 1/30sec. You still need to be careful though, because these systems don’t guarantee a sharp image every time. n What if my subject is moving? In this case, the exact shutter speed you need to freeze movement depends on how fast your subject is moving. For a person walking, a shutter speed of about 1/250sec should be enough, whereas for sports and wildlife, you might need a shutter speed of at least 1/1000sec. Very fast subjects such as racing cars or planes may require the fastest shutter speeds of 1/4000sec or 1/8000sec. Using a very fast shutter speed reduces the amount of light reaching the sensor, so for a good exposure you might need to either open the aperture wider or increase the ISO sensitivity. n Whenwould I want touse a slowshutter speed? There may be times when you don’t want to freeze movement but instead leave the shutter open for a long time to introduce motion blur for creative effects. This can add a sense of movement to an action scene or let you get creative with light

Words by Ian Fyfe

Last timewe looked at what the shutter speedmeans and how it affects your exposure, but choosing your shutter speed isn’t just about how much light you want to reach the sensor. The slower the shutter speed, the more chance there is that movement will be recorded as blurring in the image. If you want your images to be sharp, you need a shutter speed fast enough to eliminate this movement. But on other occasions, you might want to use a slow shutter speed for creative reasons. n What speed should I use for sharp images? If you’re shooting handheld, the rule of thumb for ensuring that camera movement doesn’t blur your images is to match the shutter speed to the focal length you’re using. For example, if you’re using a lens at 250mm, you want a shutter speed of 1/250sec or faster. If your lens or camera has an image stabilisation mechanism, then this often lets you get away with slower shutter speeds – for example, at 250mm, you might be able to use a

NEXTMONTH: How to use ISO to control exposures







Photography News | Issue 5

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