■ Dig a little deeper into the AF systems of most cameras, especially mirrorless models, and the potential for fine-tuning and customisation is huge. Whether that’s useful is another thing, though: it depends on what you like to shoot and how you like to work. Being able to select your favourite focusing pattern, and dedicate it to a user setting or function button for instant recall when the shooting scenario changes, is a really useful feature. A few cameras let you create your own focus zone pattern: shown here is the custom zone feature of the Olympus/OM System OM-1.
Cameras such as the OM-1 enable you to design and store your own AF pattern.