EISA recently named the Sigma 135mm f/1.8 Art as the best DSLR lens for 2017-2018, and based on my experience with this lens, I have to agree. It is a fantastic lens and performs at a very high level, with incredible detail rendering capabilities and beautiful bokeh. For the longest time, the 135mm focal length had a little bit of a gap that really needed to be filled. Canon has their version, which although is a great performer, it just can't match the likes of the Zeiss 135mm f/2. However, due to having autofocus, many tend to choose the Canon version over the Zeiss. With the release of the Sigma version, it would seem that one may no longer need to compromise.