Camera skills ISO and flash
Adjust the sensitivity for more balanced shots
Being able to adjust the ISO is useful for flash photography. When it comes to getting a good flash exposure, the choice of aperture is key, as it’s this that controls how much light reaches the digital sensor.
Because the flash fires so quickly, the shutter speed doesn’t affect the flash exposure, but it does control how much ambient light is also captured in the photo. If you’re shooting in low light, the shutter speed may be so slow that you can’t hold the camera steady during the exposure – and you’ll end up with a blend of sharp bits (lit by the flash) and blurred bits (captured during the long exposure time). The solution is to set the shutter speed to the flash’s fastest sync setting (usually 1/200-1/250 sec), then choose a higher ISO setting to capture the ambient light during the shorter exposure. The result is a sharp picture that shows a good balance between the flash-lit subject and the background.