ISO Invariance Explained

ISO invariance is one of the most talked-about topics in photography today, yet most people don’t really understand what it is. That isn’t a surprise; ISO invariance can be very technical and counter-intuitive, and it doesn’t fit well with many photographers’ general understanding of ISO. However, ISO invariance is an important topic, especially since many cameras today are close to being ISO invariant. If you want to maximize your camera’s dynamic range and avoid using “useless” ISO values, this topic is directly relevant to your photos. So, what is ISO invariance, and how can you use it to your advantage in your own photography?