6_Vib rati on reducti on
Getting sharp results isn’t just about focusing – you also need to avoid camera shake, as that may blur your shots
Blurred images due to camera shake are caused by your camera moving during the exposure. This is most common when you’re holding your camera to shoot, and using a shutter speed that’s too slow to ‘freeze’ any camera movement. The longer the focal length of the lens, the more any movement is magnified, so the faster the shutter speed you need to freeze the movement of the camera.
Many Nikon lenses have a feature called Vibration Reduction (VR) that will reduce the effects of camera shake by moving the elements within the lens itself to compensate for any movement of the camera. Vibration Reduction essentially enables you to use shutter speeds much slower than would normally be possible and still get sharp results, so it’s ideal in low light, for example.
There is a limit to how much vibration reduction systems can do, though, so if you’re planning to use very long shutter speeds, or very long lenses, then it’s still worth using a tripod (or monopod) to maximise your chances of getting sharp results. within the lens to compensate for any camera movement.
The shutter speed needed for avoiding camera shake without VR will vary according to the focal length of the lens you’re using. With an FX (full-frame) camera the rule of thumb is that you need a shutter speed of 1/focal length to prevent camera shake; so for a 200mm lens you should use 1/200 sec or faster. But with a DX model it’s best to use an even faster shutter speed, as the effective focal length will be 1.5 times longer (in other words, 300mm rather than 200mm – see Nikopedia, page 74).
Once you’ve activated the VR system you can use slower shutter Vibration reduction becomes completely redundant once you’ve fixed your camera to a tripod. Even though the systems in many modern lenses are designed to switch off automatically when they don’t sense any movement, it’s still worth turning them off when you are using a tripod. This will prevent the VR from activating if there’s a small movement, such as when you adjust the settings or reframe your shot, which can potentially cause your shot to be blurred, as the VR will move the elements inside the lens.