DPReview tells usYou probably don’t know what ISO means — and that’s a problem to explain what ISO (sensitivity) mean in the world of digital photography, compared to film, and why it is different.

This brings us to the biggest problem with using a clumsy metaphor for film sensitivity as the way of setting image brightness in digital: it means we aren’t given the tools to optimally expose our sensors.

Digital photography cameras are built on film photography. While some things are similar, when it comes to the image capture, things are totally different leading to a design that is often suboptimal at best.