The Zeiss Loxia 21mm F2.8 is the most wide-angle lens in the Zeiss collection of Loxia lenses. They take their name from a classification of bird, which I’ve grown used to seeing in Zeiss lenses, this time of a ‘chunky finch’. There’s nothing chunky about the lens, however, as it’s refreshingly compact and lightweight for such an ultra-wide-angle prime. Like the longer 25mm F2.4, 35mm F2, 50mm F2 and 85mm F2.4 lenses in the Loxia family, this one has a 52mm filter thread which makes it easy to mix and match filters across the board.
