What’s the difference between the standard ISO range and expanded ISO? Harrison Wilkins, via email

Jason says... The standard ISO range stretches to the highest ISO value at which image quality is deemed to be generally acceptable. That’s a bit subjective, however, as you might feel that a camera’s image quality becomes unacceptable even towards the upper end of its standard range.

At high ISO settings, the most noticeable degradation in quality is increased image noise. As you stretch into the expanded ISO range, images are likely to look very grainy and will also suffer from a loss of fine detail, along with a reduction in dynamic range, giving poor contrast with a lack of definition in highlights and lowlights.

Increasing the ISO setting into its expanded range is likely to cause multiple degradations in image quality