Know More About Metering Modes

Know More About Metering Modes

Modern DSLRs are equipped with a function known as Metering Mode.  Metering is letting your camera read the light that is entering the sensor and accordingly adjust the shutter speed and aperture. The recommended exposure is displayed on the bottom half of your viewfinder and also on the bottom half of your LCD screen when you turn on the “Live View” mode. There are three basic metering modes in most cameras:

  1. Matrix/ Evaluative Metering
  2. Center-Weighted Metering
  3. Spot/Partial Metering   

photo by dylan m howell

Photograph by Portland wedding photographer Dylan M Howell.

Matrix Metering: It can be said to be the default metering in every DSLR.  The entire frame is divided into a grid and then analyzed on the basis of light intensity and distribution across the frame.  It takes light from all corners of the frame and then calculates an average which is set. This is the metering mode from which you should start shooting if you are in your early days in photography. Thus this mode more often than not sets the perfect exposure. But this mode may fail in certain situations where there are extreme light and dark areas in the frame.

Center-weighted Metering: Sometimes you would not like to consider the exposure in the entire frame. Center-weighted evaluates the light in the middle of the frame and its surrounding and not take into account light from the corners. This metering mode is common across most point-and-shoot cameras.  It does not consider the focus point where it is focused and takes into account light from the middle of the frame. This works well for subjects which dominate the center of the frame like portraits. This is also useful when the Sun is behind the subject and also when the background is over-exposed.

Spot Metering: It evaluates the light only around the focus point and ignores the entire frame. It considers a very small part of the image, approximately 5 percent and does not read information from the rest of the image. This mode is useful in bird-photography since the birds have to be well exposed irrespective of the light at the foreground or the background. It works well for back-lit subjects also.

                                      

When the camera is set to “Manual” mode, there is a bar which appears with markings in both left and light along with a 0 in the centre. If the camera focuses on a bright region, the bars will show “+” and on the other hand the bars will show “-“ when exposed on a dark region. Increasing or decreasing the shutter speed will help in getting to 0 which is known as the perfect exposure. The metering mode may sometimes not execute properly if it has to expose different light intensities in the same frame. There is no ideal metering mode and it depends on the situation and the kind of lighting that helps you portray the image in the way you want.  A sound knowledge of metering modes and how these modes impact the image is to be understood to get your exposure right.