« on: March 03, 2014, 11:56:24 PM »
In general can Sigma produce a Lens at less than half the price as good as an Otus 55, or even a Zeiss 15f/2.8 ?? I'm not convinced, but it would be wonderful to see it if they could, I just don't think they can or will.
Canon made a pretty good Lens in the 50f/1.2 L, not perfect for sure but pretty good, if Sigma can drop a 50 f/1.4 Art with AF into the Market that solves some of the issues that the 50f/1.2 L has, it will sell and sell well especially with the Canon users, but the "aiming at the Otus" hype from Sigma ?? it's just that, marketing hype.
You don't know much about this lens if you're saying that Sigma's claims are marketing hype. They're the opposite. Zeiss with the Otus pioneered a radical never before tried optical design, which results in performance that is 2-5 times better than any other fast SLR 50mm ever made. It solves the standard focal length softness problem that has plagued lens designers at the standard focal lengths for the last 70+ years. Fast prime SLR lens designs around 50mm have never been able to correctly focus light at high angles of incidence because the lens elements they required had to be inside the mirror box around 50mm, this made every single design ever released noticably soft. Zeiss designed a radical new formula to fix this problem and Sigma made a slightly simplified copy of the breakthrough design.
When Sigma says they are aiming for the Otus and ignoring the competition, they mean to say that their lens makes everything else that competes obsolete. The Sigma is 89% as good as the Zeiss, and both lenses are the only standard SLR fast primes that don't exhibit significant softness. Every other lens in their class ever made is noticeably soft.
We're comparing average MTF numbers @ f/1.4 around the low 800's and 900's, for the Sigma Art and Otus, versus numbers in the high 300's and 400's for literally everything else (Lens rentals did a test of 23 different standard primes in their great 50mm shootout, which is a great point of comparison). Comparing the Sigma to anything else is like comparing swords to guns. The difference between the Sigma Art in average resolution and the nearest non-otus competitor is greater than the difference between a Tamron 18-270mm, at it's worst setting and a Canon's super telephoto prime.