I know I have said this before, but new camera technology continues to give photographers more tools than ever to ‘getting the shot.’ I shot film bodies for years, and honestly, not much changed. Frame rates got better, metering slowly improved and films evolved. I mean it was a big deal when Fuji introduced Velvia in 1990. The colors were amazing, rich and saturated, and all was well for landscape shooters. But at ISO 50, can you imagine shooting that today? I roll through my ISO settings continuously during my shoots. ISO used to be the set variable, and exposure was affected more by aperture and shutter speed. Now all three play equal parts in the exposure triangle. Why? Because high ISO performance has gotten so good. Most cameras can easily shoot at ISO 1600 with excellent results. And I regularly shoot at 3200 and higher with publishable results.
One camera setting that has gotten popular with better ISO performance is Auto ISO. Basically, you go into your camera menu, set the maximum ISO and minimum shutter speed values, and let the camera adjust the settings based on your aperture and shutter speed. Auto ISO works great for wildlife shooting when you want to keep a certain shutter speed, say 1/1000, to freeze the action. Here are the times I like to use Auto ISO:
-fast action wildlife shooting
-fast action adventure sports
-fast moving travel photography..i.e. walking through a contrasty market.
-handheld shooting to maintain a certain shutter speed.
Just to clarify, these are the times I turn Auto ISO on in my camera. Normally I shoot in Aperture mode and manually select my ISO. But why not use Auto ISO all the time? You could use it a lot, but here are some reasons to consider not using it all the time.
-using flash; Auto ISO tries to compensate for exposure shifts you want to make, and causes a lot of confusion in lighting classes. When you want manual control of your exposure, turn off Auto ISO
-deep shadows; noise shows up in shadows and dark skies more than anywhere else, and these are scenarios you may want exact control over your ISO, especially scenes that are not fast moving.
-on a tripod; I will set my ISO at my default setting, usually ISO 100, for many of my landscapes. It may be very low light, and Auto ISO might choose a higher ISO for the shot which isn’t necessary and could produce more noise.
The good news is that we have great images using ISO 1600 and higher. Whether you choose to use Auto ISO or manually select the ISO in the field, we get great results. Consider trying out Auto ISO on your next wildlife shoot. I just returned from Bosque Del Apache, and Auto ISO worked great with the changing light.