Example: aperture priority under the flashes of light supplement
For many cameras, as aperture priority exposure mode (Av) use the special flash light, photographic opportunity automatically set the shutter speed, set in two ways:
One way of flash, force to limit synchronous speed: in the environmental strong light, restricted to the highest synchronous speed; In the environmental light weaker, restricted to more than the highest synchronous speed of a low position, such as 1/60 s.
Way 2, consideration of the environmental impact of light and canon nb-5l battery
set to below the highest synchronous speed shutter speed, most are in environment light light side based on an increase, such as for certain aperture, environmental light measurement value of 1/15 s, so synchronous speed is set for 1/30 s.
One advantage is always way can guarantee a clear basis, the disadvantage is the background of the brightness of planning; The advantages of the way 2 is to consider the influence of the background, but to experience deficiencies, easy to cause the screen melt.
The use of flash is a very important principle: shooting picture looks more natural. According to this principle, the picture should consider prospects as much as subject and the background coordination, as little as possible to see traces of flash for the best. In accordance with the principles discussed the AV mode flash light supplement method.
A, indoor application example
Below is a group of indoor photos, no use a flash situation:
Background light and prospects of light show this is indoor shooting in the picture, the prospect of the main body of the exposure of the main body of the bright enough to show. At this time, a lot of people very natural to think about the use of flash of subject for light, the following is an example of the fill light different methods:
This is a way of shooting set according to 1 picture:
Because of the role of the main body of the flash bright prospects shows itself, but of the background of the exposure is insufficient, obvious by themselves, and with rich flash shadows.
If the way to set 2, because the shutter speed than canon bp-915 battery
flash synchronous speed is low, considering the exposure of the background of the elements, so in the show of the bright prospect, but also showed the characteristics of background.
Second, to choose different metering DianBu light effect
In the use of flash for light, you need to consider the difference between different metering points, because the foundation of the flash compensation is different.
For some modern have more AF system for the camera, and they have for center-weighted average metering or spot metering/local metering and move with the focus of the function. Even if not the use of AF camera, if use for center-weighted average metering or spot metering mode, on the image of different position measurement, lead to the result has the very big difference. From the following diagram can be seen above, the choice of to focus (in fact is to choose a different point/local metering area), on the final screen of influence.
Obviously, because of the brightness of the dark parts and highlights far, is beyond the scope of the recording medium allows, the result is:
If you want to ensure that highlights part of normal exposure, dark parts of a serious shortage of inevitable exposure;
If you want to ensure that the darker part of normal exposure, the highlights part necessarily severe excessive exposure.
Even though use of exposure compensation, can only make a more serious aerating part highlights:
How to solve this problem? One answer is: use flash for filling type flash.
The so-called “filling type flash”, it is a kind of method of fill light. When the subject of the picture is very strong contrast ((such as light), can use flash to fill the dark area. We can draw a picture brightness according to the vertical axis of the curve, so for brightness highlights part of the form, and the darker peak department will form the peak and valley. The so-called filling, is to use flash to “fill” the peak and valley.
Of course, in “fill” peak and valley at the same time, also can to peak department for filling, to rise. But if the darker picture of proportion is large, improved slightly darker brightness, on the vision of feeling is completely different.
Three, outdoor application example
According to the principle of the above mentioned, there is no difference between indoor and outdoor, because all want to try to meet this principle. Outdoor service is concerned, the environment the light can be divided into three types of: the positive side light, light, and light.
In a sunny/strong positive light, there is no need to use flash; In a sunny/strong light cover of things (such as the shade) or a cloudy day shoot indoor use way similar. So, in outdoor application basically consider is flash light and backlight side.
From the back of the illustrations to see, wants to make the picture appear natural must, in accordance with the highlights part based on film value to flash compensation, as to how much compensation, need according to the difference of the highlights and dark and decide.
The light of the situation of fill light side effect
1, in order to dark parts for metering benchmark
The darker part has been close to normal exposure, but highlights part already after exposure.
At this point, if use a flash to fill light, can only be a more serious aeration:
Even if the light output reduction, the highlights part still lead exposure, the effect is not good.
2, in order to highlights part is the metering benchmark
It is no use a flash of the screen, because the role of side sunshine, model facial ministry has dark shadows, the darker obviously inadequate exposure.
This time, the need to use flash for filling light, this is filling light effect:
From the picture can see, due to the environmental light was more intense, and such normal light supplement TTL in improving the brightness of the dark parts, but also give the original picture exposure normal part of the cause of the harmful effects of aeration.
Eliminate the influence of a aeration do is reduce the output of the flash, is to flash compensation. The following pictures are the flash-2 EV compensation, is to reduce the second gear flash output (namely original output 1/4). Visible, the picture liquor appropriate to improve the dark parts of the brightness, also won’t cause specular highlights of the original part aeration.
The occasion for against fill light effect
1, in order to dark parts for metering benchmark
The darker part has been close to normal exposure, but highlights part already after exposure.
At this point, if use a flash for filling light, the highlight is the only part of the aeration more serious:
Flash normal flash
Flash 1.5 reduced output file
2, in order to highlights part is the metering benchmark
It is no use a flash of the screen, because the role of backlight, model face serious underexposed:
This time, the need to use flash for filling light, this is filling light effect:
The following pictures are the flash 1.5 EV compensation. Visible, the picture liquor appropriate to improve the dark parts of the brightness, also won’t cause specular highlights of the original part aeration.
Get the ideal exposure effect.
Processing your request, Please wait....
