The Auto ISO Sensitivity Control Trick

There is a very cool trick that can get you the best of both worlds and that won’t sacrifice your shutter speed or aperture. By setting up the Auto ISO sensitivity control feature, you can set the camera to automatically select an ISO that keeps you at your preferred shutter speed, while using the largest aperture and lowest ISO possible. It will also put an upper limit on the ISO to keep you from getting too much noise in your images.

Here’s the way it works. If I am shooting an activity that requires a shutter speed of 1/250 of a second, I set that as the minimum in the auto control settings. Then I decide that I can deal with the noise that is produced with an ISO up to 1600, so I set that as my maximum sensitivity. Since I would always like to use the lowest ISO, I set the ISO Sensitivity setting to 100. Once everything is set, the camera will now adjust my ISO without any interaction from me, letting me shoot at my desired shutter speed at the lowest possible ISO and largest aperture setting possible. I used this feature when shooting the evening soccer game in Figure 5.5, and it allowed me to keep the shutter at 1/640 of a second on into the night.