Exposure Compensation and Auto Exposure Bracketing Options

photoling Posts: 457 Points: 1743
Posted: Thursday, August 3, 2017 12:05:52 AM

A camera's automatic exposure meter is not always able to calculate the optimal exposure. As a result, exposure compensation is used to adjust the meter's exposure value (EV). For example, when an image contains strong reflections, the reflected light can cause the image to become dark, or underexposed. On the flip side, if you take a picture of that same person against a black background the camera will want to overexpose the image to get away from having clipped shadows. When this happens, applying plus compensation creates an optimal exposure.

Exposure compensation can increase (brighter) or decrease (darker) the standard exposure set by the camera. The change in light amount of 1 EV is equivalent to changing the shutter speed or aperture value one level.

  • If you’re in Aperture Priority mode(Av/A), spinning the wheel   in either direction will adjust the exposure compensation up or down using shutter speed to let in more or less light.
  • If you’re in Shutter Priority mode(Tv/S), spinning the wheel will adjust aperture to let in more and less light.

If you are at 0 exposure compensation, you will see a mark in the middle of your exposure meter on your cameras LCD or in the viewfinder. If you spin the wheel in either direction, you will see the mark move either up or down.

Although you can set the exposure compensation up to 5 stops in 1/3 stop increments, the exposure compensation indicator in the viewfinder and on the LCD panel can only display the setting up to 3 stops. If the exposure compensation amount exceeds 3 stops, the end of the exposure level indicator will display < or > sign.

 The exposure compensation amount will remain in effect even after you set the power switch to <OFF>. To cancel exposure compensation, set the exposure compensation amount back to center indicator.

photoling Posts: 457 Points: 1743
Posted: Thursday, August 3, 2017 8:45:11 AM
Plus Compensation Minus Compensation Other Compensation Examples
When the subject and scene are white When the subject and scene are black Strong sunlight streaming in from the window Accentuating the flower's whiteness
The high reflective ratio of white causes the image to be underexposed, darkens people and turns white to gray. The low reflective ratio of black causes the image to be overexposed and turns the black subject whitish. Strong sunlight streaming in from the window causes the person in the foreground to become dark and underexposed. Using the automatic exposure value.
«(+4/3)EV «(-4/3)EV «(+1.0)EV «(+2.0)EV
Adding +4/3 compensation gives a natural color to people's skin and accurately reproduces white subjects. Adding -4/3 compensation faithfully reproduces the black-colored subject and creates an optimal exposure. Adding +1 compensation allows us to clearly see the person. Adding an extremely large amount of plus compensation has the effect of accentuating its

photoling Posts: 457 Points: 1743
Posted: Thursday, August 3, 2017 9:17:57 AM

In P, Tv, and Av modes, the camera sets either the shutter speed or aperture, or both, to produce a good exposure, and the meter displays the current Exposure Value setting. Because you don’t need the meter to tell you whether exposure is okay in these modes, the meter instead indicates whether you enabled Exposure Compensation, a feature that forces a brighter or darker exposure than the camera thinks is appropriate.

  • When the exposure indicator is at 0, no compensation is being applied.
  • If the indicator is to the right of 0, you applied compensation to produce a brighter image;
  • when the indicator is to the left, you asked for a darker photo.

Assume you are shooting in aperture priority, and you have chosen your aperture based on the subject matter but find that your image is constantly dark. By adding +1/2 or +1 stops via the exposure compensation on your camera you will lighten the image overall.  When in aperture priority, because you want the aperture to remain the same, the camera will use a slower shutter speed to compensate.

Conversely in shutter priority mode, by adding +1/2 or +1 stops via the exposure compensation on your camera, the camera will open the aperture, allowing more light to reach the sensor (or film). The reverse is true if you are finding your image is too light, dialing in a minus exposure compensation number will darken your image incrementally.

photoling Posts: 457 Points: 1743
Posted: Thursday, August 3, 2017 12:00:33 PM

Another classic example is photographic birds or aircraft in flight. Even the best exposure meters will generally expose for the sky leaving the bird or plane dark in comparison. Again dialing some plus exposure will lighten up your subject although possibly at the expense of a washed out sky.

A typical example that may over expose is a forested landscape; the darkness of the trees can very often trip up a meter. Here, using minus compensation will help correct exposure.

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