Light Meter
The light meter displays the exposure value (EV) you are receiving. This is the amount of light coming in through your lens using the shutter and aperture values along with your ISO settings. When using manual mode take a look at your light meter it will let you know if you’re are underexposing or overexposing your photo. You may or may not want to overexpose or underexpose your photo and this will let you know the exposure on your photo.
The light meter in your camera measures the amount of light your picture will receive. It takes into account your shutter speed and aperture. Usually you want your light meter to be in the center unless you are trying to get a special outcome with your picture. Overexposure is where you get too much light and Underexposure is where you get too little light for your subject. You may want to overexpose if you’re taking a picture in very bright conditions like show or if your subject is in a shadow or if your subject is darker then the background. You may want to underexpose if you’re taking a picture and want more color saturation on an overcast day or if your subject is lighter than the background or maybe you want a silhouette.
Use your camera's exposure preview to see if you have over exposed something. Most cameras you can view the photo an then select the exposure preview option. Over exposed parts will be shown by blinking parts of your photo or by blacked out parts.