Essential camera skills
Set up your camera to get the best possible exposure of a scene
No matter how respectable your Photoshop skills are, it pays to know your way around your camera – and in particular how to get exposure right. Exposure is controlled by three factors.
Aperture and shutter speed enable you to manipulate the amount of light that hits your camera’s sensor, while ISO controls your sensor’s sensitivity to this light. Different combinations of the three factors give a huge variety of results. Our tips will (ahem) shed some light on the subject…
SHOOT IN RAW
One of the advantages to shooting in raw is the room for error when it comes to setting exposure. Compared to JPEGs, recovering detail in shadows and highlights gives noticeably better results. With raw files, not only will you record greater detail, you‘ll also have more control when it comes to tweaking tones and white balance. This is because JPEGs are processed in-camera, which means a great deal of information is discarded. Raw files, on the other hand, contain a complete record of all the data captured by your camera. So while JPEGs have the advantage in terms of file size and compatibility, raw gets the maximum possible quality from your camera.
Shutter speeds
Your camera’s shutter is positioned in front of the sensor, and opens for a period to allow light through. The longer the shutter speed, the greater the amount of light that reaches the sensor. For long shutter speeds, a tripod may be necessary to keep the camera steady. As a general rule, you can get away with hand-holding for speeds that match the focal length: think 1/50 sec for a 50mm lens and 1/200 sec for a 200mm lens. Shutter speed works with aperture to give you a correct exposure. For example, if you capture a scene at f/4 using 1/250 sec, to record the same scene at f/11 you’ll need to increase the exposure time to 1/30 sec.
Lighting tips
Beginners often think bright sunlight is the perfect lighting for taking a portrait – but if it’s sunny overhead, the light is usually very unflattering. For better results, find a spot of shade or wait for the angle of light to get lower. Alternatively, place the subject’s back to the sun. This results in an attractive backlit portrait.
Strong directional light from behind can be difficult to balance out across an image. From the hard shadow under the model’s chin, you can tell that a flash has been used to illuminate her face. Without this, the face would have been unbalanced and lacking in detail. So when you shoot into the sun, try a burst of flash or use a reflector to bounce light back onto the face.
Aperture The opening in your lens that allows light through to your camera’s sensor is called the aperture. By changing its size, you can control the depth of field of the scene. Aperture size is measured in f-stops. The larger the f-stop number, the smaller the aperture and the greater the depth of focus. With a landscape, you’ll usually want sharpness throughout the scene, so an aperture of f/16 or above is the right choice. Conversely, when it comes to portraits, you’ll want an uncluttered, blurred background, so a small aperture of f/2.8 would be best. IS O SE N SITIVITY In the days of film, ISO related to the sensitivity of the film to light. Capturing a scene on ISO 400 film required half the amount of light needed on an ISO 200 film. Similarly, in digital photography, ISO settings change the sensitivity of your camera’s sensor. Lower ISO settings will result in less image noise and finer detail, but will also have an impact on the amount of light required. The lower the ISO setting, the greater the amount of light needed to get a good exposure. Compare shooting hand-held outdoors on a bright day with shooting in a dim interior. Outdoors, you could usually use ISO 200 or even lower, while for dim interiors you’d probably need ISO 1,600 or higher.