How to accurately measure the face of a backlit portrait?

Answer; We are often told not to shoot people in the back light when using a fool's camera, because a fool's camera will shoot people's faces black. However, what we are using now is not so retarded. With various manual functions, it is easy to take a good backlit portrait. Everyone likes that kind of photo with a circle of golden light on his face! \n There are grading standards for the methods described below, with 5 papers being the highest and 0 the lowest. \n Universality: refers to whether this method can be used in most DC, where 5 means it can be used basically and 0 means it can't be used basically. \ nDifficulty: refers to the difficulty of application, with 5 indicating that it is easy to use correctly and 0 indicating that it is extremely difficult to master. \ nEffect: refers to the picture quality that is used properly, with a score of 5 indicating good effect and a score of 0 indicating poor effect. \n \ n \ The first method: exposure compensation method \ nUniversality: 5 points difficulty: 3 points effect: 2 points. \ nUsing exposure compensation to shoot backlit portraits can be said to be the most commonly used technology. Although many people point out that it is not suitable for dc (exposure latitude low), it is not as good as the twice metering in fc. However, because most fools or semi-fools don't have too many manual functions, they can still be applied when the contrast between the background and the subject is not too big. The difficulty mentioned here refers to the difficulty of judging when it can be used and when it cannot be used. From an operational point of view, it is certainly not difficult. For the exposure compensation method to shoot a backlit portrait, the first difficulty lies in the judgment of ambient light when shooting. When the brightness difference between the background and the theme is too great, this method cannot be used, otherwise it is inevitable that both the subject and the background cannot be taken into account. \n Its principle is that exposure compensation is added to increase the brightness of the subject because multi-zone metering will cause the subject to be dark. \n The specific usage method is: in the case of multi-zone metering, take a photo at+1.0 EV, +0.7 EV and +0.3 EV, and choose the best Zhang Baocun. It is better to have EB, which can be done automatically. If people's face is still too dark when using+1.0EV, then exposure compensation seems inappropriate, because if this continues, the background will inevitably exceed the tolerance range of DC, and it will be glistening. When using exposure compensation method to shoot backlit portraits, we should fully consider the color of clothes and the proportion of hair in the picture. Let's borrow a work from Living Area to illustrate the problem. The photographer of this photo added+1.0ev because it was backlit. However, he forgot to consider the influence of dark clothes and hair. In fact, in the multi-area metering mode, dark clothes and hair, which account for 40% of the picture, have balanced the influence caused by too much background light. So adding EV is redundant. Please refer to the histogram to judge the exposure at this time. \n \n \ The second method: point face measurement \ nUniversality: 4 points difficulty: 5 points effect: 3 points \ nPoint face measurement is essentially the same as exposure compensation method. That is, the desired exposure is obtained through the improvement and correction of automatic metering. It is simpler than the exposure compensation method, and there is no need to take multiple photos for comparison. It also avoids the possibility of misjudgment in the case of figure 1 The disadvantage is that it is still impossible to have both sides when the contrast between the background and the subject is too great. \n Its principle is that people are most concerned about people's faces in photos. As long as the face is properly exposed, it doesn't matter if the other parts are slightly worse. The reflectivity of wampee is quite close to 18%. \n The specific application method is: measure people's faces with spot light, and then shoot them. \ nOne thing to pay attention to when using this method is people's skin color. White people and yellow people are not a big problem. If you shoot a black man, it will inevitably be overexposed. In addition, on some machines with very small spot measurement area, if people have shadows on their faces or loose hair, it will also affect the accuracy of exposure. \n In short, spot metering is very simple and the best method in general application. \n \ n \ The third method: reflector method \ nUsing reflector is a kind of light supplement method, which is very suitable for shooting backlit portraits. Moreover, due to the variable light distribution position, many additional effects can be achieved. For example, the most commonly used bottom reflector is the principle that the bottom lamp can take out the eye bags and dark circles of the characters, which can beautify the appearance of the characters while increasing the goodwill. \n Its principle is: use the reflector to reflect the ambient light to the face, increase the brightness of the face, and narrow the brightness contrast between the background and the subject, so as to obtain an ideal photo. \n The specific application method is: use multi-zone photometry, place a reflector under people's feet, hit the reflection on people's face, and then shoot. \n As I said before, what I want to talk about here is the different applications of both sides of the reflector. Basically, the golden side can get warm light (high color temperature), and the face of the character will be warmer and smoother; The silver side can get the effect of cold light (low color temperature), and the face of the character will appear lonely and straight. The general application should be based on gold surface. \n There are also problems with this method. First, the reflector is not easy to carry, and it is still very large when folded. Second, it is not so easy to find someone to help make a reflector; The third is that using too many reflectors will make the photos feel fake. But in any case, this method is much better than the first two. \n \n \ The fourth method: flash method \ nUniversality: 4 points difficulty: 2 points effect: 4 points \ nMany people think that flash is used when the light is insufficient, such as at night. In fact, this concept is greatly wrong. \n Its principle is: to increase the brightness of the subject with a flash, and to narrow the brightness contrast between the background and the subject, so as to obtain an ideal photo. \ nIt is difficult to shoot with a flash. First, if the flash is too hard, it will destroy the light perception of the scene and make the photo fake; Second, the flash limits the use of the aperture; Third, the flash is still the same after all. \ nThere are many ways to fill the flash, so I will introduce them one by one: \ nMethod 1: Use the built-in flash or the external position flash. Firstly, ev is determined by measuring background light with automatic gear; Then switch to manual gear, use flash index /2/ shooting distance/to determine aperture, and use reciprocal rate to determine shutter speed. To shoot. \n For example, if the flash index is 12, the shooting distance is 3m, and the background photometric result is F4.0, 1/250, then the final aperture is12/3 = F2.0, and the shutter speed is 1/65438+ according to the reciprocity ratio. (When using mirror shutter, please consider the synchronization speed of curtain shutter. The reason why the aperture should be reduced in the usual index is to keep the light ratio between the subject and the background within an acceptable limit and avoid false situations. \ nMethod 2: Use the built-in flash, or use an external camera to flash, but add a layer of gauze on it. Firstly, ev is determined by measuring background light with automatic gear; Then switch to manual gear, use flash index/shooting distance/to determine aperture, and use reciprocal rate to determine shutter speed. To shoot. \ nThis method is also used to soften the light and reduce the light ratio. Compared with the first method, the effect is better. \ nMethod 3: Use the external flashing light of the handle to fill the light at the side position. Firstly, ev is determined by measuring background light with automatic gear; Then switch to manual gear, use flash index /2/ distance between flash and main body/to determine aperture, and use reciprocal rate to determine shutter speed. To shoot. \n For example, if the flash index is 24, the distance between the flash and the subject is 6, and the background photometry result is F4.0, 1/250, then the final aperture is 24/2/6=F2.0, and the shutter speed is11000 according to the reciprocity ratio. (Use mirror shutter, please consider the synchronization speed for curtain shutter) \ nThe problem with this method is that you need tripod and remote control or self-timer. Or just having an assistant. The advantage is natural light.