Originally posted by Pål Jensen A Ferrari is about performance. Performance in a lens is about optical quality which has nothing to do do with lens speed. A fast lens should be compared to a truck.
Sometimes I think fast glass is about selling insecurity, preying on those who want to take better photos and based on hearsay they are told and then believe that f/1.8 is "better" than f/3.5.
Then you look at almost all their photos and realize they shot 90% of them at f/5.6 or smaller aperture
And the ones they shot at 1.4 all have that same OOF aesthetic which...everyone has when they shoot at f/1.4. A common critique I have of a lot of portraits, mostly casual...a good pro know better, is too shallow DOF. The should have stopped down more, not less.
High ISO has done far more to "get the shot" than fast glass.
I'm not saying the Sigma is a bad lens; I am saying it is as niche as a Fast 50. Its size alone makes it a marginal product in today's overall market. I reiterate that what makes the lens feasible at all is that Sigma can cross brands to get a reasonable volume. Without that, this lens would not exist as a single proprietary brand could not sell enough.