Doing Exposure Compensation Manually on a Digital Camera

Written by Malina Monday, 12 April 2010 05:07

Reflective meters on a camera set a exposure so that the overall tone of the subject appears at middle gray (18%). When the subject has an overall tone that is lighter than middle gray, the photograph will appear too dark.

 

 

Reflective meters on a camera set a exposure so that the overall tone of the subject appears at middle gray (18%). When the subject has an overall tone that is lighter than middle gray, the photograph will appear too dark. When the subject has an overall tone that is darker than middle gray, the photograph will appear too light. There is a 5-stop range of recognizable tonality. Detail-less black is 2½ stops darker than middle tone and detail-less white is 2½ lighter than middle tone. When the overall tone of the the subject is middle gray (18%), the reflective meter will set the correct exposure and the photograph will appear to have the correct exposure. Once you recognize what tone the reflective meter is setting the exposure to, you will be able to make the correct compensations. Compensations can be controlled by the aperture, the shutter-speed or the compensation dial.

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The 3 major Auto Exposure Programs:

* Program (P) - The camera suggests a shutter speed/aperture combination based on the chosen focal length. Some of the smarter camera models allow to "shift" the program ( changes the setting to the next nearest shutter speed/aperture setting. The exposure value (EV) remains unchanged ). A "P" program without Shift mode cannot be used for more than just P&S - including Shift it is a good general purpose program.

* Shutter Priority - This program is targeted for Action photography where you want to insure that you have a fixed shutter speed e.g. in order to prevent blurred images. The camera cares about an appropriate aperture setting here. The exposure value (EV) remains unchanged again.

* Aperture Priority - This is usually used to control DOF ( Depth-of-Field ) - portraits may be a good application for this program. The camera automatically cares about the appropriate shutter speed. The exposure value (EV) remains untouched again here.

By reading these steps you should be able to successfully adjust your exposure compensation on your digital camera.

1、The first step is to pick your subject and point your camera the way you are going to take the picture.

2、 look at the light meter on the LCD screen of the camera. You should see a series of lines on the lower right of the screen. To have good exposure compensation you want the meter to be in the middle section of the lines. To do this you must adjust aperature, shutter speed, or ISO. Aperature (the measurement is a F-stop) is the diameter of the opening where the light is coming into the camera. The shutter speed is the amount of time light is allowed into the camera. Lastly, ISO is the sensitivity of the image (the lower the ISO the higher the quality).

3、The last step was more to inform you on the different things you can adjust to have correct the exposure compensation. You are also going to want to know what a stop is. A stop is a full step in either letting more or less light in. You will need to know this because by speeding up shutter speed one stop you can keep the same exposure compensation by either lowering your ISO or by decreasing your aperature.

4、To compensate correctly, you must change these settings to correct the light compensation. The following are the different stops on each setting. These are most, but not all of the stops. The stops are in order from letting the most light in to letting the least light in.

Aperature - 2 2.8 4 5.6 8 11 16 22

Shutter Speed - 1" 1/2 1/4 1/8 1/15 1/30 1/60 1/125 1/250 1/500 1/1000

ISO - 1600 800 400 200 100 50 25

5、Now we can get into the actual adjustments.The room is too dark. You need to compensate by letting more light into the camera. To do this you have to change settings on you camera to let more light in. You can increase your aperature (go to the left on the chart). You can decrease your shutter speed (go to the left on the chart). Keep in mind if you go longer than 1/60sec the picture may be blurry. To deal with this either put the camera on a tripod or compensate the aperature. You can increase your ISO (go to the left on the chart). Keep in mind if you go to 800 or 1600 your image may appear slightly blurry. This is because the image sensitivity isn't high enough.

6、The subject is too bright. To adjust for this you want compensate by decreasing aperature (go to the right on the chart), increase the shutter speed (go to the right on the chart), or increase ISO (go to the right on the chart). Generally this is easier than trying to adjust for subjects that are darker.

Warning

Exposure compensation is easier to learn when there is too much light.

Try practicing a sunny day before you mess around with a subject that is darker.

Keep in mind that adjusting exposure compensation with dark subjects can be more confusing.

Try to have a ISO of 400 or less.

Also, try to keep the shutter speed 1/60sec or faster if you aren't using a tripod or bracing the camera.

 

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Last Updated on Tuesday, 16 November 2010 11:55