How to use several metering modes

1． Common digital camera metering modes

Multi-area evaluation metering is also called average metering or matrix metering. The camera's metering system divides the captured image into multiple areas for evaluative metering to determine an appropriate exposure combination. Different cameras have different shapes and digits of divided areas, ranging from dozens to hundreds. For example, Nikon COOLPIX775 and 5700 digital cameras have 256-area matrix metering modes. This multi-area evaluation metering mainly refers to the position of the subject to determine the metering weighted proportion of each area, and then determines the exposure value after a comprehensive measurement. It is more scientific and practical, and is the metering method most frequently used by photographers. When shooting common landscape photography, travel photography, family life photography, group photos, news photography and other subjects, you can basically get more accurate exposure by using this mode. That is to say, as long as the brightness of the subject and the background is relatively uniform, and the area ratio of the subject and the background in the picture is relatively normal, the multi-area evaluation metering mode can be used.

Center-weighted metering: The metering area focuses on the center of the screen, and the rest of the area is metered evenly. Basically focus on the subject, while giving due consideration to the relationship between the subject and the background. This mode is more suitable for close-up flowers, half-length portraits, product still lifes and other subjects with the center of the picture as the main expression object. As for the size of the "center" area when metering, it varies from camera to camera. It generally accounts for about 20 to 30% of the entire frame. When Nikon D1X and D1H meter in this mode, 75% of the metering is concentrated on the central 8mm diameter. Within the circle, this is also a more practical light metering method. Relatively speaking, most photographers will place the subject in the center of the picture when shooting. If the subject is obviously tilted to one side, or the middle brightness is obviously brighter or darker in the entire picture, and the brightness is not representative, it should not be used. model.

Spot metering The metering area of ??spot metering is limited to a small position in the center of the screen. Generally, cameras with more than 4 million pixels have spot metering functions, such as Sony DSC-S85 and F707, F717, F828, etc. All have spot metering modes. In order to meet the extremely strict exposure requirements of professional photography, some advanced digital SLR cameras have a very small spot metering angle. For example, when Nikon D1X and D1H are used for spot metering, the metering range is concentrated in a 4mm circle in the middle of the screen, which is quite large. Since it only accounts for 2% of the entire frame, photographers can choose very independent metering parts or content in the frame as they wish, and can set the "point" they choose very accurately. This is mainly to meet the needs of photographers to ensure that the exposure is exactly as they want in an environment with a huge difference in brightness between the background and the subject. When shooting backlights or side backlights, spot metering is often required. Especially when shooting on stage, spot metering is often required to eliminate background interference due to specific lighting effects such as concentrated lighting by follow-up lights.

Focus AF area metering is also a metering mode with relatively high practical value. Generally speaking, in photography practice, the focus point chosen by the photographer is often the main expression object, whether it is in focus This area will be the focus in terms of selection and exposure factors. The focus chosen by the photographer when shooting is also used as the focus of metering, which can be said to kill two birds with one stone. Usually professional digital single-lens reflex cameras have this function to facilitate capturing moving objects. Some popular cameras also have similar functions. For example, the 4300, 5000, and 5700 models in the Nikon COOLPIX series all have focused AF area metering functions. Metering is completed while focusing, which also saves precious time for photographers who need to capture the moment.

2. Requirements when using "spot" metering

If you compare several metering modes, relatively speaking, the most difficult to master is "spot metering". The characteristic of spot metering is "only focus on one point and not the rest". When metering, the brightness of other parts of the subject is not considered at all. Therefore the chosen metering point is very important. First of all, the photographer needs to know what brightness "point" is suitable as a sampling object, and understand what brightness this point should be restored to in the final image. It should be said that the criterion for selecting this "point" is that it must have a brightness equivalent to 18% neutral gray. If you select a "spot" that is too bright, you will get an overexposed image; if you select a "spot" that is too bright, you will get an underexposed image.

So when using the spot metering mode, it all depends on the photographer’s practical experience, but this mode plays an important role in specific situations. As shown in Figure 1, the picture of "Red Lotus Dragonfly" is relatively typical. The subject is in the middle and the surrounding colors are relatively simple. You can get better results by shooting in spot metering or center-weighted metering mode.

As shown in Figure 2, the lighting in "Stand Out" is relatively complex. The main subject is bright, but the surrounding background is darker without being directly illuminated. The overall brightness of the picture is low and the contrast is large. Only the two flowers on the subject are brighter. For such a picture, it is best to use spot metering to determine the exposure combination, and then lock the exposure combination or adjust the camera to manual mode before shooting. This will give you a more ideal effect.

3. The impact of different metering modes on exposure when using flash

Since digital photos have relatively high exposure requirements, photographers should pay attention to them in addition to shooting in natural light. In addition to choosing the appropriate metering mode, you should also pay attention to the impact of different metering modes on exposure when using flash.

Many photographers believe that the metering mode is closely related to the use of ambient light, but the metering mode does not matter when using flash. In fact, the information exchange and processing between modern flash and cameras are very closely related. When flash lighting is used, different metering modes will also have different effects on photo exposure. For example, the Nikon SB-800 flash has an automatic balanced exposure mode. That is, the flash emits a pre-flash that is invisible to the naked eye before flashing. After the pre-flash, it automatically analyzes the brightness of the subject and the background in the scene. At the moment of the actual flash, the flash automatically According to the brightness difference between the subject and the background, corresponding exposure compensation is made to make the brightness of the background and the subject relatively coordinated. When the photographer selects the average metering mode or the center-weighted metering mode, the flash can automatically complete the balanced exposure, so that the contrast of the resulting picture will be relatively soft. If the photographer only wants the subject to be properly exposed, regardless of the brightness of the background, or wants to retain the original brightness difference between the subject and the background (due to the balance compensation, the exposure of the subject is affected by the background to a certain extent: if the background brightness is high , the subject will be appropriately underexposed; if the background brightness is low, the subject will easily be overexposed). If you do not want the flash to compensate for balance, you should select the "Spot Metering" mode.

4. Use various metering modes flexibly

Although digital cameras (including traditional cameras) have metering modes, some modes require the photographer to have certain photography knowledge when using them. , you need to have a clear understanding of the camera's metering principles, otherwise, it will be counterproductive. Therefore, for generally inexperienced photographers, it is recommended to use the "multi-area evaluative metering" (i.e. average metering) mode. This mode is also the mode used by general cameras in program file (P) (usually as the factory setting). ), it can comprehensively balance the brightness of the subject and the background to provide a more scientific exposure. It is a "fool" mode that is more trouble-free and more reliable. Figure 3 "Xin'an River Scenery" was shot using the average metering mode, but considering that the overall brightness of the picture was lower than the brightness of 18% neutral gray, a -1.3 stop of exposure compensation was used, and the resulting tone was ideal. This shows that although photographers can use various metering exposure modes when shooting, they still need to flexibly deal with the tonal characteristics of the subject in a timely manner and make corresponding exposure compensation when necessary. Only in this way can the ideal image quality be obtained. .

When the subject is in the middle of the screen and occupies a large proportion, you may wish to select the "center-weighted metering" mode, so that the exposure obtained will be more accurate. Figure 4 "Brazilian Wolf" was shot using the "center-weighted metering" mode. Considering that the wolves and grassland occupying the main area in the picture are close to the 18% neutral gray brightness, in order to ensure the accurate exposure of the Brazilian wolf, we Use the wolf in the middle as the main metering reference for exposure. The exposure parameters are: aperture F5.6, shutter speed 1/400s, and the final effect is quite satisfactory.