SLRL doesn't typically do the data-heavy type of gear reviews this forum craves, but their Sigma 85 Art review did offer something rarely reported:
https://www.slrlounge.com/sigma-85mm-f1-4-art-review-the-beauty-of-this-beast/
We've discussed a fair amount about inconsistent Sigma 35mm Art and 50mm Art lens AF performance, in which it is neither front- nor back-focused but inconsistently missing (and therefore not dock-correctible). Most lens reviewers tend to dwell on (a) AF speed (b) AFMA/dock-correctibility rather than basic reliability.
LensTip reports AF hit rate, but tends to do it in lab controlled conditions. I think it's also helpful to check the phenonmenon in the field, and SLRL did just that:
"Using back-button AF with cross-type AF points on a Canon 5D Mark III, we put it through its’ paces. Out of all shots fired, the Sigma 85 Art only missed 30% (70/250) of the shots taken, and some due to unexpected movement of the subject. That is extremely proficient, especially considering that the Canon 85L, when put in the exact same scenarios, missed 40% (100/250) of shots, so chew on that.
The focus consistency is similar to the previous Art lenses, but perhaps a bit improved. The missed focus moments aren’t as apparent as seen in the 50mm and 35mm Art lenses, meaning that the 85mm barely misses the mark and then regains focus upon the next click while it’s Art siblings take a bit more time to compose themselves."
This is the first hit rate study I've seen on this lens, and it's a very promising finding. I consider AF inconsistency the #1 weakness of Sigma's Art Primes, so stacking up favorably to the 85L -- even in a non-controlled / potentially not apples-to-apples scenario -- is very good news.
I welcome more work in this area [cough save us Dustin, you're our only hope cough], but for now, the 85 Art is looking good.
- A
https://www.slrlounge.com/sigma-85mm-f1-4-art-review-the-beauty-of-this-beast/
We've discussed a fair amount about inconsistent Sigma 35mm Art and 50mm Art lens AF performance, in which it is neither front- nor back-focused but inconsistently missing (and therefore not dock-correctible). Most lens reviewers tend to dwell on (a) AF speed (b) AFMA/dock-correctibility rather than basic reliability.
LensTip reports AF hit rate, but tends to do it in lab controlled conditions. I think it's also helpful to check the phenonmenon in the field, and SLRL did just that:
"Using back-button AF with cross-type AF points on a Canon 5D Mark III, we put it through its’ paces. Out of all shots fired, the Sigma 85 Art only missed 30% (70/250) of the shots taken, and some due to unexpected movement of the subject. That is extremely proficient, especially considering that the Canon 85L, when put in the exact same scenarios, missed 40% (100/250) of shots, so chew on that.
The focus consistency is similar to the previous Art lenses, but perhaps a bit improved. The missed focus moments aren’t as apparent as seen in the 50mm and 35mm Art lenses, meaning that the 85mm barely misses the mark and then regains focus upon the next click while it’s Art siblings take a bit more time to compose themselves."
This is the first hit rate study I've seen on this lens, and it's a very promising finding. I consider AF inconsistency the #1 weakness of Sigma's Art Primes, so stacking up favorably to the 85L -- even in a non-controlled / potentially not apples-to-apples scenario -- is very good news.
I welcome more work in this area [cough save us Dustin, you're our only hope cough], but for now, the 85 Art is looking good.
- A