Auto ISO


Today’s Question: What are your thoughts about the use of the Automatic setting for ISO?

Tim’s Quick Answer: My personal preference is to not use Auto ISO, but I certainly recognize that some photographers find it to be a convenient way to help ensure they are always using an adequately fast shutter speed.

More Detail: Most cameras that feature an Auto ISO option also enable you to set an upper limit for the ISO setting. This would enable you to ensure that the ISO will only go as high as you are comfortable with in terms of noise in your final image. That certainly mitigates my primary concern about Auto ISO, which is that the ISO will be set higher than I would like it to be.

That said, I still prefer not to use Auto ISO simply because I prefer to establish a fixed setting for ISO based on the current lighting conditions. When the light changes significantly or my preferences for the overall exposure settings change, I’ll dial in a new ISO setting. But in general I simply prefer to make a conscious decision about changing the ISO setting, rather than having the camera make that decision for me.

But again, I don’t think there is anything wrong with using the Auto ISO setting if you find it to be helpful in your photography, provided you set an upper limit for the ISO based on the noise behavior of your camera, and that you monitor the actual ISO setting that the camera is establishing for your images.