Intermediate Tutorial 5
It is great when you can make the most of your camera’s automatic systems. Exposure Compensation is particularly helpful, as it allows you to override a camera’s light level metering when it is having difficulty, without turning off all auto functions for full manual operation.
The art of photography is the art of capturing light. Too much light and the image will be overexposed, too little and it will be underexposed. The correct amount of brightness in an image allows us to see its detail, shade and texture. Getting the exposure right is about finding the right level of brightness in order that we can see the subject correctly lit.
However, it is not always easy to judge correctly, as often the light level is not even across the whole of the frame. Sometimes, too, even a modern digital camera’s sophisticated automatic exposure system will get it wrong. Take, for example, this typical image (right) where the subject is in front of a very strong light source.
Here, the camera’s metering system has detected the light source – natural light from outside the window – and set the exposure accordingly. The problem is that this level of exposure is too dark for the actual subject in the room, and so the result does not allow us to see her face.
Luckily, sophisticated digital cameras are equipped to allow a quick correction of the ‘exposure value’ (EV). This control is known as ‘Exposure Compensation’ and is usually denoted by this symbol (right).
How to use Exposure Compensation
Some cameras have a dedicated EV button and some rely on pushing the control wheel to select it. Once selected, turning the control wheel dials in the compensation in small steps. Cameras usually allow plus or minus two, three or even five stops of exposure control. Adjustments on the plus side will increase the brightness of the image; adjustments on the minus side will darken the image. Returning the setting to zero will return the image to the camera’s initial exposure value.
In the case of our example image, if we increase the EV by a couple of stops, the image becomes brighter and the subject far better defined, as you can see in the second shot here.
Exposure Compensation is one of the most useful controls on a modern digital camera and provides the flexibility of being able to carefully tweak exposure to suit your shooting conditions – but without having to turn off auto and resort to full manual operation.
Exposure Compensation can be used whenever you are shooting in Programme Mode, with Aperture Priority or with Shutter Priority selected. It is not offered in Manual Exposure mode, however, as that relies on you selecting both your aperture and shutter speed for correct exposure, manually, as discussed in previous tutorials.
Our example of a subject sat in front of a window with the daylight flooding in behind her demonstrates a great use of this function – but any situation where you find your camera struggling to select an appropriate exposure is a good reason to use it.
How metering effects exposure
The camera’s ability to expose a scene correctly relies on its built-in metering system correctly choosing which part of the scene to expose for. Setting the camera to the correct metering mode can help with this.
Three metering mode settings are normally offered:
- ‘Multiple’ or ‘Matrix’ – this evaluates the brightness of the whole scene and sets the exposure accordingly
- ‘Centre Weighted’ – this evaluates the whole scene, but takes more influence from the focus object at the centre
- ‘Spot Metering’ – this targets only the subject in the centre of the scene and exposes accordingly for that
Of course, the camera cannot always know that the light reading it takes is based on the subject you want to feature in the photograph. So, setting a metering pattern that is relevant to your specific subject will help the camera to get it right more of the time.
Exposure Compensation for creative control
Not only does this function provide a quick fix for exposure problems, it also offers additional freedom and creative control. It enables you to deliberately under- or overexpose your shots for creative effect.
The two shots here show how deliberately underexposing – in the second image – reveals more details in the clouds behind the subject and creates a different mood. You can see how this detail was lost entirely with standard exposure. Sometimes, you have no choice but to compromise the overall brightness in order to bring out details in certain parts of the frame.
Live View, an essential for EV monitoring
When making adjustments such as activating Exposure Compensation during an actual shoot, the ‘Live View’ function of your camera comes into its own. Frankly, it is essential!
When shooting in Live View mode, the effects of all adjustments to the exposure value can be easily seen on the preview screen in real-time while you are making those adjustments. So, you know exactly what you are going to achieve with your shots.
The LUMIX Advantage
LUMIX G cameras include not only full-time Live View, enabling you to monitor all Exposure Compensation adjustments as you go, but the G6 model also includes a manual function that offers fingertip control of EV adjustments – via a simple push-pull lever, as shown right.
To experiment with Exposure Compensation, try taking a shot of a subject standing indoors in front of a window, with bright sunlight outside. Firstly, get the shot without the function activated, so you can see how difficult it is to correctly light such a scene. Then use Exposure Compensation to dial in some extra brightness on your subject. Don’t forget, Live View allows you to monitor any adjustments you make before you take the shot itself.
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