Get correct exposure at every shot by reading about the exposure triangle and experimenting with manual, semi-automatic and automatic shooting modes on DSLR.
When we talked about the exposure triangle, we saw what there are elements those actually determines the amount of light that enters the camera. We have also seen that, in automatic and semi-automatic shooting modes, the DSLR camera is able to help in calculating the correct exposure. But even in manual mode the camera should be able to tell whether the combination of ISO, shutter speed and aperture that we are using is leading us to a correct exposure. To be able to do these things, the camera must be able to measure the light, in order to measure the exposure.
Introduction to get correct exposure
Therefore a DSLR is equipped with sensors (that is light meter) and algorithms that allow to evaluate the light that enters the lens or the light that is reflected from the scene. In modern digital cameras, the most usual ways of measuring exposure are three : matrix, Center-weighted and spot metering. In the rest of the article, we will see how they work and how to use them. As with other articles on this website, you can read the information that will be useful if you are owner of a digital SLR. The compact cameras, probably will not give you the option to select the metering modes.
Get Correct Exposure at Every Shot
Matrix metering is the most common mode of exposure measurement on the current cameras. In this mode, the exposure is calculated taking into account the large part of the scene. In addition, depending on the algorithm used, so depending on make and model of the camera, other factors can be considered other factors such as colors, the distance from the subject in focus, etc. Matrix metering may or may not be the same as Evaluative metering.
When to use: The main aspect to consider is that the calculated exposure will depend on the scene as a whole. Therefore, matrix is ??useful in all situations where there is extreme contrast between the foreground and the background. Basically, as claimed by many photographers and experienced authors, this mode of measurement of exposure is good in 90% of cases. In fact, this is the default mode of measurement in almost all digital cameras of recent production.
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Center-weighed metering was widespread as default on DSLR cameras a little time ago. It considers the entire scene but gives greater priority to the central area. As you can read from many sources, although this mode is still present in many cameras (if not all), was almost overcome and replaced by the matrix metering.
When to use it: As greater priority given to the central portion of the scene – implies that this method of measurement should be used when the main subject is in the center of the frame and a background too light (too bright); matrix metering will underexpose the foreground. Of course, you can use it even when the main subject is not positioned centrally. In this case it is necessary take in the middle of the frame, measure, lock the exposure and then recompose the scene.
Spot metering calculates the exposure in a small area surrounding the point of focus. The extent of this area is equal to about 3% of the entire scene. A variant of this mode is the partial measurement, in which the area used for calculating the exposure is more extensive, at around 10%. Since the point of focus can be moved, spot metering does not require you to place the subject in the center of the foreground. A disadvantage of spot metering is that, the small size of the measurement area can sometimes make it difficult to calculate the exposure. To get around this, if the camera and the scene permit, you can try partial metering.
When to use it: there are some situations where the measurement spot can become truly indispensable. Generally, these are situations in which the main subject of the photo is in stark contrast to a portion of a lot more (or much less) brighter the image. A common example is that of a portrait where the light comes from behind the subject. In cases like this, it is very useful to use spot metering and precisely position the point of focus on the subject.
