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Compensation for very bright backgrounds - Photography
Although having a bright background can create a very good opportunity to capture cool silhouettes, a subject photographed against the light may end up being dark against your wish. This is a challenge mostly when subject need to be clearly identified, therefore the need to know how to compensate the light coming from the front side.
The contrast in brightness between the subject and the background makes the exposure system to adjust itself to the most dominant area, for instance if your subject occupies a small area with a very bright background the exposure system adjust itself to the dominant area which is the bright background, this leads the camera into assuming that your scene is overexposed because of the background and ends up reducing the overall exposure making your subject appear under-exposed. The same case applies when you have a small subject occupying a small areas that has a dark background, the camera will assume your whole scene is under-exposed because of the background and hence it will allow more light through, the end result will be your subject will appear over-exposed. The level of the error depends on how large the background area compared to the subject.
Surface Area: One of the ways to have a balanced exposure if at all you have to use auto-exposure is to reduce the surface area of the background, this means tightening up you image to cover a limited background, this will make you subject occupy relatively more space and the exposure system will likely use your subject for adjustment. But what about in instances where you have to include the background?
Exposure compensation: one way to compensate for inadequate light on your subject or too much light on your subject is to trick your camera into allowing more light. To lighten up your subject you increase the exposure compensation by 1 stop, you specify +1 to open the aperture or slow down the shutter speed. You use this when you have bright backgrounds than the subject. To darken the subject you decrease the exposure compensation by 1stop, you specify -1 to reduce the aperture or increase the shutter speed. How much exposure compensation you need to set depends on the tonality of the background and the effect you are trying to achieve, one way to determine the right exposure compensation is to use exposure bracketing vary your exposure by shooting three different shots, in this way you at least get one image close to the right exposure. The first exposure is made at the setting recommended by the camera (0). For the second, exposure is increased (+) to make the image lighter. For the third, exposure is decreased (-) to make it darker.
Spot/Partial Metering: this measures a small area in the scene, without being influenced by other areas in the scene. It can be at the centre on another part depending on whether your camera has got the function to change from the centre. This makes it very useful in high contrast scenes since the camera is able to identify the most important part of your scene. In cases where the background is too bright or too dark compared to the subject, spot metering will concentrate on the subject and exclude the background making your subject to be well exposed without being influenced by the lighting in the background.
Reflector: use a reflector to bounce back the light from the background if it is the background that is too bright. You will find this very useful mostly when shooting close-ups.
Flash: useful when the subject is near e.g. portrait photography, this counters the light coming from the background.
Shoot RAW: if your camera supports RAW format, it’s wise to use it if you realize that after exploiting the above setting you still are not getting the right exposure. The RAW format allows you to shoot an image that you can easily manipulate later during editing in post-production