Difference of ISO exposure compensation flash in photography

Exposure compensation, when you set the AV file (aperture priority), the shutter will+-speed on the basis of metering, and similarly, when you set the TV file (aperture priority),+-aperture value. The background and subject light and shade change together.

Flash compensation, only for aperture value+-,flash has a distance limit, only for low beam, and the environmental background is still adjusted by shutter value.

ISO adjustment, the overall brightness will change. However, with the increase of ISO value, the noise will increase obviously, especially after it is increased to ISO800. People who want the maximum image quality will try to lower the ISO to shoot.

As mentioned above, the flash has a distance limit. According to different models, the internal flash distance is generally within 2~ 10M, and the external flash output is much larger. GN parameter represents the flash index. The greater the index, the greater the irradiation distance. There must be a flash for long-distance shooting.

In addition, the external flash can also be equipped with a soft light cover to make it shine on the surface, so that the light is softer and can be irradiated from multiple angles to obtain different effects, while the built-in flash can only be irradiated from the front, so there is no built-in flash in the top fuselage, because the top machine will definitely consider the external flash with the flash.