Sigma's 85mm ART series lens was released late October 2016. I've been using this lens for almost a year and it's been the best value-for-money photographic purchase that I've made. After a year of predominantly shooting weddings, events and portraiture here are my conclusions.
The general consensus is that the 85mm is considered a portrait lens because of its capability to isolate the subject from the background. All those pictures that you see with those extremely blurred backgrounds are usually taken with an 85mm.
It's categorized as a telephoto lens alongside the 70-200mm, 200-300mm, 150-500mm etc., although it doesn't act like other telephoto lenses where they would compress the background too a much greater extent.
This telephoto ability makes the fixed 85mm focal length ideal for capturing candid shots where the subject is unaware of your presence as well as getting extremely detailed close-up shots. Making it great for shooting intimate portraiture.
With the Canon EF 85mm f/1.2L II being the most relevant exception, the maximum aperture of f/1.4 is as wide as apertures get. This allows more light to reach the sensor allowing the photographer greater flexibility, especially in low light situations. This flexibility allows the photographer to require less ISO usage, which transfers over to better image quality. The aperture ranges from f/1.4 to f/16
There's no image stabilization but unless your shooting video it doesn't really matter because of the amount of light that the lens lets through onto the sensor is more than enough to make sure your shutter fires fast enough to freeze the subject.
After using the 85mm on a Nikon D3s body, what stood out most was the amount of detail captured. Even at f/1.4 the amount of detail and the sharpness of the image set it apart from previous non-sigma lenses that I've used in the past. This sharpness and detail is extremely important because say you're shooting a bride in her wedding dress. You need to be able to see what kind of fabric the dress is made of. If you've lost the detail in the shot, in my opinion you might as well have lost the shot.
At f/1.4 the edges of the image still remain very sharp. Some lenses tend to blur the edges when the aperture is wide open, forcing you to lower the f-stop. This blurring of the edges is more prevalent in wider focal lengths. At nearly half the price of its Nikon and Canon counterparts, the image quality stands alongside its high-end counterparts.
Already being an owner of three of Sigma's Art Series lenses and having used the 85mm ART's predecessor, the 85 EX DH HSM f/1,4, the first thing that I noticed was that the speed at which the lens locks onto the target was faster and more precise, mainly due to the re-engineered autofocus system inside the lens. Compared to its Art sublings, the 85mm also seems to regain focus much faster. Much like an eager kid trying to find sweets.
As a wedding, events and portraiture photographer the rate at which the lens locks onto the subject is crucial when considering which lens to buy. If your lens doesn't focus fast enough, you WILL lose shots. This loss of shots is completely unacceptable when you have these special moments that only last for split seconds. You must ensure that your equipment is up to the task.
The focus consistency is similar to previous art lenses, in that they don't always get the subject in focus. Over time, Sigma Art lenses tend lose their consistency in AF compared to their Nikon and Canon counterparts. Why this happens I'm not really sure. In my 1 year of using this lens I've had to re-calibrate it twice. The first sign is that your hit rates would drop dramatically. This change in hit rates is very evident. This requires the user to tweak the lens through AF micro adjustments via the USB dock, as well as more factory servicing to maintain focus consistency. Luckily, as long as your lens is still under warranty, Sigma is willing to calibrate your lens for free.
I've realized that there is still some issues with focusing in low-light and also that the lens find focuses faster through using focus points at the center of the frame as opposed to the edges. In certain conditions, especially where the subject and background are both dark, the lens struggles to focus. the lens will try to acquire focus while jittering back and forth until it eventually gives up. You then have to manually intervene and *reset* the lens or opt to shoot the lens manually. There have been some situations this past year where I've had very little to no natural light along with no infrared assistance from flash. In these situations I've had to resort to manual focus and in this case the enlarged focus ring makes for a very pleasant and precise experience.
Above you'll see the 85mm attached to a Nikon Df. the first thing that you'll notice when handling this lens is the size and weight. It's around 40% larger than its predecessor and weighs in at around 1.2kg. This is heavy for a prime lens. If you weren't looking and holding the lens attached to a body, you'd assume that you're holding a 70-200mm lens. Other Sigma Art collection lenses don't have this kind of weight. The weight is mainly due to the contents inside of the lens which consist of 14 elements arranged in 12 groups.
The exterior is made of Thermally Stable Composite (TSC) material along with traditional metals. Although it isn't fully weather sealed, it does feature a rubber gasket on the mount that makes it highly resistant to dust, water and sand. With sand being one of a photographer's worst nightmares, especially living in South Africa, this helpsfor keeping sand away from the sensor. Though I would still take my chances in light drizzle, this lens is not made to function in extreme weather conditions.
To conclude this review, I would say that I am very happy with this lens and how it has performed over the last year. Having mainly used my 70-200 for 90% of my telephoto requirements in the past, this lens has elevated my standard of work as well as my creative ability to better document and present a visual story. The 85mm's exceptional low-light capabilities make it a powerful tool for any wedding, portrait, landscape and event photographer.