Many new digital SLR cameras now come with a feature called Auto ISO, which automatically adjusts the ISO sensitivity of the camera based on pre-programed algorithms and user preferences such as maximum allowed ISO and minimum shutter speed.
Is this feature useful?
The typical support argument for the Auto ISO feature goes like this: Camera lenses have the maximum aperture limitation. At a given ISO, the required shutter speed to achieve proper exposure may be too slow to stop motion or avoid camera shake even when the aperture is at its maximum setting. In this case, the ISO setting of the camera needs to be raised until a usable shutter speed can be obtained. This previously human-involved process can be automated by the Auto ISO feature.
Still need to see some more convincing arguments or have some questions answered about the usefulness of the Auto ISO feature? Professional photographer Steve Simon shared his thoughts on the Auto ISO feature in Nikon DSLR camera in two discussion threads on Flickr:
Keywords: Auto ISO, Exposure, ISO, Nikon, Sensitivity, Shutter Speed