# Sigma 85mm f1.4 ART lens owners' feedback please...



## Darkly (Jul 6, 2017)

Hi All

I've read the reviews and I know about Sigma's well-documented AF inconsistencies, but what are these things like to live with?

I've recently sold my 85mm f1.2L II as I was offered a very keen price, and while I appreciate it's a true artist lens I just got sick of the lateral CA issues when newer designs such as the Sigma Art, Zeiss Milvus and Samyang XP offer up better performance at a marginally smaller aperture. I'm tempted by the Sigma design as it's received many positive reviews, and even if the AF lacks consistency at least it's an option that the Samyang and Zeiss designs don't offer.

I'm sure the Canon fanboys will say the f1.2L II can't be touched but (and in spite of me being Canon-loyal) I've had my time with it and found its limitations. The f1.2 aperture is nice - and unique for an 85mm AF lens - but I can live with f1.4 quite easily for all the potential benefits offered.

One very specific question, on the subject of AF inaccuracy with Sigma's reverse-engineered AF algorithms, does this issue still manifest when using live view or is it restricted to phase-detect AF? I generally used the Canon on a tripod using live view, manually checking the focus was where I needed it to be (and for all those people who praise the Canon it could and would miss focus on occasion with PDAF, necessitating LV for critical images).

Just to be clear, I'm only interested in hearing opinions from Sigma owners as this is the lens that looks to fit my needs - if it's not a dog to live with of course...

Cheers, Darkly


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## aceflibble (Jul 8, 2017)

First up, you'll be better off asking and looking in the board for third-party lenses, located HERE.

Now, the AF is complicated. The good news is that the Sigma lens doesn't use focus-by-wire like that Canon 1.2 does, so right away both auto and manual focusing is more responsive to changes, if not necessarily any faster when simply using one-shot, single-point AF. Compared to the Canon 85's AF in that basic situation, it's about the same speed; if there is any difference it's a matter of tiny fractions of a second, too short for any person to accurately measure. Personally, I've not been able to tell a difference in one-shot AF speed, going from the Canon 85 to the Sigma. I do notice a difference with continual/AI focus, or when very quickly trying to go from one focus point to another; that's where the Sigma's proper focus system is slightly snappier and, as I said, responsive to the changes required.
For manual focus the Sigma wins hands-down; that Canon is one of the worst lenses in the world, in my experience, for manual focus, and that alone is why I gave up on the Canon and got the Sigma. (The improved optics were just a bonus.) If you do any manual focusing, even just tweaking, you'll appreciate the Sigma.

_However_, AF accuracy is another matter. Like all of Sigma's lenses from the last few years, it'll both front-focus and back-focus at different distances when using regular focus, until you calibrate it with the Sigma USB dock. The good news is that dock is cheap and once you've calibrated it once, you're set. (Assuming your body is also calibrated and working accurately; that's up to you, though, nothing to do with the Sigma.) Also my 85 wasn't as bad as the 'DC' Sigma zooms have been. (The 18-35 and 50-100 being notorious for having unfixably bad random back- and front-focusing.) The ease of fixing it and how good the lens is once you've corrected it means I wouldn't really consider it an issue; if you already have the dock and are used to calibrating gear you can have it sorted out in what, 30 minutes?

AF with live view _is_ perfectly accurate, but as always, a little bit slower. That's the trade you always make with live view/mirrorless shooting. I've not noticed the Sigma being any slower than any Canon lens when using Live View shooting. The random back/front-focusing doesn't occur when using Live View.


From the way you describe your shooting, I'd say the Sigma is the right choice for you. If you mostly shoot with a tripod and often with Live View, the Sigma is faultless. Genuinely faultless. For more 'regular' shooting it has it's niggles but they're corrected easily and it's still miles ahead of the Canon.


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## Darkly (Jul 10, 2017)

aceflibble said:


> First up, you'll be better off asking and looking in the board for third-party lenses, located HERE.
> 
> Now, the AF is complicated. The good news is that the Sigma lens doesn't use focus-by-wire like that Canon 1.2 does, so right away both auto and manual focusing is more responsive to changes, if not necessarily any faster when simply using one-shot, single-point AF. Compared to the Canon 85's AF in that basic situation, it's about the same speed; if there is any difference it's a matter of tiny fractions of a second, too short for any person to accurately measure. Personally, I've not been able to tell a difference in one-shot AF speed, going from the Canon 85 to the Sigma. I do notice a difference with continual/AI focus, or when very quickly trying to go from one focus point to another; that's where the Sigma's proper focus system is slightly snappier and, as I said, responsive to the changes required.
> For manual focus the Sigma wins hands-down; that Canon is one of the worst lenses in the world, in my experience, for manual focus, and that alone is why I gave up on the Canon and got the Sigma. (The improved optics were just a bonus.) If you do any manual focusing, even just tweaking, you'll appreciate the Sigma.
> ...



Brilliant.

That's exactly the response I needed, thanks for taking the time to provide such a complete answer. Thanks also for pointing me in the right direction for future 3rd-party lens posts.

Cheers, Darkly


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## pwp (Jul 10, 2017)

You must have read up on reviews.
https://www.google.com.au/search?q=sigma+af+85mm+f/1.4+art+review&ie=UTF-8&oe=UTF-8&hl=en-au&client=safari
Lots to read here.

-pw


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