Camera ISO

The third most common way to get more power out of your flash is to increase your camera’s ISO. If you make the camera more sensitive to light, then your flashes don’t have to work as hard to illuminate the subject. If you increase your camera’s ISO, your flashes can work from a greater distance (figure 3.39).

How does this work in a real-world application? Let’s say I’m taking photographs in an area where the ambient light is fairly low and my subject is far away, like a concert or an evening soccer match. If I want to use fill flash, then the Speedlight might not have enough power to reach the action. In this situation, I would bump up the camera’s ISO to the sensitivity required to get the shot.

Notice that when you change the ISO on your camera, the SB-800, SB-900, and SB-910 display the new ISO on their LCDs. Also, as you change ISO, the flashes display the new usable distance values on their LCDs (figure 3.39). You get the same effect with the SB-600, but it doesn’t show the distance value on the LCD.