If you prefer to swap lenses constantly and can live without all the other focal lengths then feel free to do it your way, carrying around three lenses, losing time when swapping them, and exposing the DSLR mirror box to potential dust. Also, when shooting with two or more primes, each one rendered the colors a bit different, which needed special care in PP to get consistent look. With one lens, you do not need to handle each focal length differently. Since I do not plan to go FF I really do not need FF coverage.

Question to you and DPR: how resistant to flare is this lens? My Sigma 17-50 f/2.8 has a tendency to show greenish flare patterns in somewhat easy lighting conditions, like as in light coming from a lateral window. This is important for my shooting needs. Nikkors have much better flare characteristics, in my exp.

You must have a different monitor than I have. I find it hard to beat for the money and the range, speed. What else you going to buy?

No idea what you're looking at buddy. Looks like a superb lens to me and credit to sigma for going for Quality over anything else. I'm not a zoom lover by this is a truly great concept.

@Thematic:
You do know, that You are not obligated to buy it if The do, right?

Any company that puts resources and finances towards products that consumers won't purchase or will dislike in large quantities reduces the potential for efforts spent on products like the excellent Sigma Art series of lenses.

You do know that right?

+1 Thematic. Although I hear what PKDAnny is saying. We'll gradually lose the wonderful quality and storytelling of Sigma Art lens line as soon as Sigma gets lustful for its own cameras bodies and starts to inevitably lose money.

Perhaps surprise me, Sigma, and come out with something like a non over heating GH4/a6300 with internal prores and (practically) no rolling shutter. Please throw in 10 bit color and flat profiles, as well, Surprise us.

digital picture reviews are flawed.

The main selling point of the Sigma is the F/1.8 aperture. Stopping down makes it a lot less desirable since you run into 70-200/4 lenses for full frame which are smaller, cheaper and stabilized.

Fact of the matter is the Sigma is soft wide open compared to any modern 70-200/2.8 which are also stabilized. And if you stop the Sigma down you lose the only advantage it's got compared to full frame.

There have been many cases of the digital pictures results being at odds with the majority of other websites. This is a fact regardless of their testing methods. Whether they do something wrong or just get bad copies they have presented some obviously superior lenses as being softer than inferior ones on more than one occasion.

The site is flawed, stop using that site when there are other sites that are more trustworthy.

I don't really see how a 75-150 equivalent FL zoom is replaced by an 85mm prime.

On the contrary. With a D500 or a 7D2 (plus d7200 & 80d) I see a revival of the APS-C sensor cameras (not to mention Fujifilm's X System and Sony's A6xxx camera series) ;-)

Apparently Nikon Didn't get your memo by producing the D500

I'd not say days of APS-C are over considering amazing popularity of Sony A6xx series of camera. They have their own place in every photographers bag.

I'd like to see the days when comments like yours come to a close...

You are aware that the 'Crop' sensor DSLRs outsell FF DSLRs by about 4-1 aren't you? You make it sound like the format is on it last legs when that is nowhere near being the case atm.

Manufacturers may want everyone to upgrade to FF, and so higher prices for cameras and the more expensive lenses that those cameras demand, but for the vast majority of people a crop sensor camera is a more suitable format. Canon and Nikon may be pushing people towards FF with the marketing and new lenses, but that leaves are large market for the 3rd party lens manufacturers, like Sigma, to take advantage of, if Canikon are targeting the top of the market. Sigma seem to be the company coming with innovation and hopefully quality.

This post has created a profound somber sadness :( Many a sports and wildlife photographer has been crushed by the declaration announcing the end of the APS-c. I now question if life is worth living and if I can continue on. So-so sad!!!

It weighs as much as a dozen prime lenses?

Half a dozen may be :)

I wouldn't throw that full frame setup just yet:

http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=1048&Camera=963&Sample=0&FLI=0&API=0&LensComp=833&CameraComp=0&FLIComp=0&APIComp=0

That link compares f/1.8 vs. f/2.8. Set both to 2.8 and the Sigma is back on top.

What advantage is there for the crop system if you shoot the Sigma at F/2.8?

I thought that camera was only just ok for Sports photography. It seems to be great for Street/Portrait photography as well.

also Sony A6000 and Sony A6300

Adding MC-11 makes this an E-Mount version.

Canon's 20 or 30 year old prime is good in your view?

I am only an amateur, but I enjoy shooting sports with Canon's 85mm f1.8 and their EF-S 17-55 f2.8. I am a huge fan of the 85, but the athletes are not always considerate enough to place themselves within the narrow compositional bounds demanded by any prime lens, no matter how excellent it might be. The Sigma lens is larger, heavier, and more expensive, but I see nothing to indicate that the IQ is inferior to what I have, so it seems likely to be more versatile for my needs.

They should have ask you for advice before producing the lens.

Those Sigma fools!!!

These are beautiful pictures, but how much shallower depth of field would one want? Look at the photos of the very patient woman—in some her eyes are in focus but everything else is out. In some only the bridge of her nose is sharp, and others it's only the tip of her nose but in both those cases her eyes are unacceptably soft. It seems to me you could capture all her beauty AND separate her from the background by having her step farther away from the wall and shooting at 5.6 like a sane person.

It made me lol when you said "the very patient woman". That rings true since my wife and kids stop cooperating after the second or third time the shutter goes off, so any subsequent pictures have frowns and scowls. Impatient women!

@FastGlassLover, It's not really fair to compare the size of an 85mm/1.8 prime to a 50-100mm/1.8 zoom that covers an equivalent range of 75-150mm. As you said, physics is not going away.

In the past, you needed a FF sensor to get excellent high ISO performance. But sensors have gotten so good that APS-C is already good enough for nearly any photographic opportunity.

So that leaves things like DOF preference (do you want more, or less?), edge sharpness (smaller sensors are less challenging here), lens/body size/weight, and cost, etc. And there's no single definition of "best" for every user.

To me, it's kind of like trying to debate whether it's better for a sports car to have a big V8 or a smaller turbocharged 4-cylinder. Both approaches have their pro's and con's, but at the end of the day, current technology allows either one to provide blistering performance.

Long story short...it's a good time to be a photography enthusiast!

To me it looks fluffy

To me it looks tasty.

... What?