02-21-2017, 08:57 AM
Quote:Which fast 85mm APO ? The Otus ?
Yup. If one is going to acquire an f/1.4 lens then presumably they are planning to use it wide open. The pursuit of clinical resolution wide open is diminished if marred by distracting and ugly LoCA flaws. I think to imply that it's OK on this Sigma because other lenses have it is too kind.
I don't know that much about optical design and costs, but one reference comparison on the market is the Leica 50mm f/1.4 Summilux and the Leica 50mm f/2.0 Summicron APO. The latter is a full stop slower (i.e. it's optically HALF the size) but is priced 170% higher than former. (OK, Leica can charge whatever they want but I'm taking the pricing at face value.)
APO does not come easy (i.e. cheap) and that is one of the unique qualities of the Otus so I think it's not informative to lump it in with the other lenses but to add the differences of the Otus to the discussion of the SIgma.