8 flash cannot not know common sense

If there is no light, the photography is not exist. Nature is full of all kinds of light, to the level of the picture, color, the influence of the atmosphere are the key. But when insufficient light, artificial light will come in handy, hot boots flash for easy to carry and color temperature close to natural light, artificial light is to use the most. With good flash is not easy, however, the following sharp introduces several flash use common sense, let you have a further knowledge of flash:

1. Understand the flash index
Flash index (designed.the GN) is one of the standard to measure the flash power. It has two functions: one is the manufacturer to identify the size of the flash power, the greater the ＆#118alue of designed.the GN, said the greater the power. The second is when manually flash photography is used, flash exposure aperture size calculation, formula is designed.the GN = aperture x distance (ISO100 as benchmark). For example: when the flash was designed.the GN = 20 (calculated on a meter), and is the object distance of 5 meters, an aperture for the F4 exposure to normal. When was the object distance to 10 meters, the aperture should be set to F2 to be effective.When the flash when power fails, you can use the larger aperture and increase the ISO method. Larger aperture can increase into the light, but at the same time, the depth of field will be affected, so generally get more power will increase use ISO method.

2. The role of the shutter
Flash is the feature of fast and strong. Light in the form of light instant attack, usually in 1/1000 of a second to 1/1000 seconds flash, and the extremely short exposure time, can much more quickly than shutter speed through the lens into the sensor, so in general, under the condition of the aperture and the output power is constant, the shutter speed does not affect the flash exposure, but it can affect the environment of light exposure. For example, when you use 1/15 and 1/500 of a second, respectively, shoot the same scene, the flash is completed at the same speed of 1/1000 of a second early exposure, so flash exposure body will not change, change the exposure is scene, 1/15 of a second more than 1/500 of a second will be bright.

3. The flash mode
Manual mode, but also experienced photographers have been using and designed.the GN = aperture x distance formula is used as the related adjustment. At this time the amount of light output is the photographer set according to actual condition, can achieve the ideal effect of flash. Such as adjust lose light after using ae lock, again by adjusting the shutter speed to show the ambient light. But the disadvantage is that every time the adjustment needs time, is not conducive to capture.Automatic mode, under this mode, when we fixed the flash and lens aperture size (consensus), after the power within the effective range of the flash, flash can calculate according to the own photographic system fill light is enough or not, the size of the automatic control of flash output, to achieve accurate exposure. At this time can adjust exposure through the aperture.TTL mode, also belong to automatic mode. TTL is the abbreviation of "ThroughtheLens", meaning "through the lens," the way is the light through the lens into the fuselage metering device, measure the flash output, more accurate. Have E - TTL Canon, nikon has I - TTL, are almost mean. When trigger the shutter, flash also triggers the fill light, reflected light and through calculation of fill light is enough or not, such as measure underexposure, automatically increase the flash output to achieve sufficient exposure.

4. The flash exposure compensation
Automatic flash mode is given a normal exposure, and many times we need to increase or decrease exposure to meet demand. This and adjust exposure compensation method is the same as the camera, flash exposure compensation can be adjusted on the transmission light, to achieve the desired effect.
5. Surrounded by flash exposure
Flash exposure (FEB) surrounded with camera surrounded by automatic exposure (AEB) principle is the same. In this mode, the user can select a specific range of exposure (1/3 and 1/2 or 1 Ev), a total often taken 3 (0 Ev, + Ev, - Ev), surrounded with exposure can make results more reliable.

6. The flash zoom
Zoom lens and zoom lens, flash and to cover more range, and zoom lens to achieve synchronous, consistent with the lens under the specific focus of field of vision. In TTL mode, flash the focal length automatically matching the most close to the lens focal length. Change the flash focal length, will also change the projection distance and the intensity of the light beam. To narrow the focal length, the light can cover a wider range, and the light become less intense. Increase the focal length, the beam will be gathered and brightness.

7. High speed synchronous
Using high-speed synchronous flash, can get rid of the limit of flash sync, to achieve higher shutter speed, can also be 1/8000. It not only can rapid solidification, and very suitable for to use large aperture control depth of field. But in this mode, the intensity of the flash will be lower, so tend to be close to the object.

8. Slow sync
As long as the shutter under the highest synchronous speed of the camera and flash can be synchronous with the shutter, only the shutter, the longer the ambient light will be bright. Slow sync is actually use the ambient light and flash of superposition, the shutter speed to background brightness, flash thought subject brightness, and finally makes the subject and background exposure, and below said after the match the curtain sync, is often used in the night portrait.