100-400mm lenses are popular among photographers of many genres ranging from birds to landscapes, as they offer an extremely versatile focal length range suitable for a lot of applications. For Fujifilm X Series users, the new Sigma 100-400mm f/5-6.3 DG DN OS Contemporary offers that versatility at a relatively affordable price, making it an intriguing option. The excellent video review takes a look at the sort of performance image quality you can expect from it in practice.