All of you must have heard about metering modes in cameras. They help in giving cues for clicking exquisite pictures of even the dullest objects and backgrounds. For understanding the metering modes, you need to know a few things about the meter of the camera, as well. So, in this article, let us discuss what is metering in photography and how a meter works.
Clicking a good picture whether it is a portrait or a wedding primarily depends on the exposure to light. Metering helps in reading the light exposure to remodel a picture and make it more clear. Earlier, simple metering patterns were present, but with the advancement in technology, new metering modes have come up.
While metering is helpful for photographers, it is not essential to know how to use all the modern metering modes. Three primary metering modes are still as good as they were earlier. So, focus on learning how to use them and then build on this knowledge further, to understand other modes as per your requirements.
Calculations Involved in Metering
Simply speaking, a meter is the camera’s brain, and the metering modes tell this brain how to think. The meter of the camera evaluates the exposure in a frame by measuring the brightness values in every scene as per the current aperture, ISO, and shutter speed settings. The meter calculates an average figure from these brightness values and matches it with the ideal exposure percentage for any scene.
For instance, a completely dark part of a frame has an exposure of zero percent, while a completely white part like the background will have an exposure of one hundred percent. So, if the area of the frame covered by these two components is equal, the meter will calculate an average of these two values, that is, an average of 0 and 100, which is 50 percent.
Now, 50 percent is the ideal exposure percent for any scene in every camera. So, the meter will signal the exposure indicator of the camera to point on zero, meaning ideal exposure. However, if a scene has an exposure percentage more or less than 50 percent, the meter will signal the exposure indicator to deflect from zero, suggesting an over or underexposed shot, respectively.
Types Of Metering
The aperture, shutter speed, and ISO form the exposure triangle of the camera. A combination of these controls allow light to enter into the camera, which then decides how the sensors will work to produce an image. For this reason, there should be a mechanism to measure the light that enters the camera. There are two ways to measure this, and thus, two types of metering patterns that you can use.
The first method is used in older cameras and some new generation cameras as well. In this method, the incident light is measured for calculating the ideal exposure. The incident light is the one that is falling directly on the subject. For this, a light meter is used.
In the second method, the camera reads the light that reflects off the body of the subject. Most digital cameras make use of this technique and apply an exposure light meter to read the reflected light.
Ideally, as per the laws of reflection, the incident light should be equal to the reflected light. However, in practice, this is not true. It is because the colors, materials, and other properties of the subjects in a frame cause them to reflect light differently.
Popular Metering Modes
The patterns by which the meter of a digital camera reads the reflected light are called metering modes. Different cameras can have different patterns. However, three of them are common to most cameras available today.
1. Matrix Metering
The most common metering mode is the Matrix metering mode. Experts suggest that matrix metering is the best for beginners. It is because Matrix metering divides the field into different zones and evaluates each of them separately for exposure. It then makes calculations, and concludes to tell you whether the exposure is right or not. It also compensates for the backlight when the background is too bright or too dull.
2. Center-weighted Metering
The second metering mode is the center-weighted metering mode. In a center-weighted metering mode, the meter reads the reflected light in about 60% of the field area. In an evenly lit frame, the center-weighted metering mode is as good as the matrix mode. However, if the background is too bright then the center-weighted metering mode can make mistakes in evaluating the dark spots in the frame, as it does not compensate for a backlight.
3. Spot Metering
The third type of metering is through the spot metering mode. Having good experience in handling different exposures and in clicking pictures with other modes is essential for using the spot metering mode effectively. As the name suggests, the spot metering mode picks up a small spot from the whole field and assesses the exposure.
It can be somewhere around 3-5 degrees in the complete plane of the scene. The spot can also be moved throughout the frame. Generally, the spots that meters pick up are the same as the focusing points of the lenses. So, by moving the focus point to different parts of the field, you can read the reflected light from these parts separately.
These three metering patterns are common to most digital cameras. The metering modes can also be used with any other mode of the camera, like manual, aperture priority, program mode, shutter priority mode, etc.
From the information stated above, we hope that you understood what is metering in photography, very clearly. While metering provides great assistance in photography, you should remember that there is no ‘correct’ exposure in this craft. Thus, you can use metering to read and adjust the light as per your requirement and thus, click desirable photographs. If the image looks good even with several spots of underexposed lighting, then you should go ahead and click it. After all, the ultimate goal is to click good pictures and not well-exposed pictures.