By increasing the ISO speed, this will increase the camera’s sensitivity to light (photosensitivity), so you can capture bright shots with a glimmer of light. If you raise the ISO speed and shoot the flash at the equal time in the telephoto shot, the flash will be capable to reach a further distance. Enough brightness can also be achieved easily if the flash intensity is weak. Here I will explain the effects that can be obtained from combining high-speed ISO with flash photography.
After placing the emitter of the flash unit at a greater distance from the subject, the light will spread to a wider area, and therefore will weaken the irradiation on the subject. In this case, you can increase the ISO speed to improve photosensitivity (photosensitivity) of the camera. By doing so, you can gain sufficient brightness, even if the intensity of the flashlight is weakened. If you want to buy Canon flash, you can visit our website.