35mm and 50mm are two of the most common focal lengths, but in the past few years, we have seen a small influx of 40mm lenses, which offer a unique perspective that is fun to work with and is a nice alternative from the two more common options. For Sony shooters, there is the FE 40mm f/2.5 G, and this excellent video review takes a look at the lens and the sort of performance and image quality you can expect from it in practice.