This lens was right out of the box and onto my camera. I found the focus to be tack sharp without any tuning and all focal lengths tested. Great color and contrast. Focus was fast and quiet. The constant length, and non-rotating lens is a plus for me.

The Sigma 50-100mm f/1.8 DC HSM ART is a quite awesome tele-zoom lens for portraits - it is very sharp in the image center and it has a very good bokeh. However, at least technically it has its weaknesses. The outer image field is good but it stays short of brilliant.

This lens looks and feels quality. Be warned its is a bit of a monster, and is a heavy weight. The image is sharp and beautiful. I have two Sigma art lenses (I also have the 18-35) now and opted for these as they are billed as professional quality glass for aps-c cameras.

First quick impressions: - very sharp at 1.8 - very smooth and creamy bokeh - extremely high build quality...the zoom ring smoothness is otherworldly - i have not experienced any focus issues so far...auto-focus is fast and silent..

I want to say I love this lens.It is amazing no doubt.The only reason for 4 stars is cz of how heavy this baby is.If ur using a tripod or mono pod ur sorted which I think is the way this lens is built.But if ur going to be moving around a lot its quite a work out.

The Sigma 50-100mm F1.8 DC HSM Art ($1,099) is a premium telezoom lens, aimed at photographers working with APS-C SLRs. It's designed around the same principle as the standard 18-35mm F1.8 DC HSM Art zoom, and is likely to appeal to the same demographic.

Very sharp; Bright maximum aperture; Nominal distortion; Rotating tripod collar; Compatible with Sigma USB Dock; Available for multiple systems

Heavy; Short zoom range; Omits image stabilization; Focus may need adjustment; Pricey

The Sigma 50-100mm F1.8 DC HSM Art ($1,099) is a premium telezoom lens, aimed at photographers working with APS-C SLRs. It's designed around the same principle as the standard 18-35mm F1.8 DC HSM Art ($698.99 at Amazon) zoom, and is likely to appeal to the same demographic. It's a bright lens, maintaining an f/1.8 aperture throughout its range, that makes no compromises on image quality compared with shooting prime lenses. That requires quite a bit of glass, and when coupled with a tough build you've got a big, hefty lens. It omits image stabilization and is on the pricey side, but optical performance is superb. It's an excellent option if you're in the market for a wide-aperture telezoom for your APS-C SLR. Design The 50-100mm F1.8 ($948.05 at Amazon) is a big lens. It measures 6.7 by 3.7 inches (HD), weighs 3.3 pounds, and supports 82mm front filters. The barrel is a mix of metal and polycarbonate, with a metal tripod collar that rotates and locks into position every 90 degrees...

The Sigma 50-100mm F1.8 DC HSM Art is an appealing lens for APS-C SLR owners who want a bright telezoom, but it's on the pricey side.

Very sharp; Bright maximum aperture; Nominal distortion; Rotating tripod collar; Compatible with Sigma USB Dock; Available for multiple systems

Heavy; Short zoom range; Omits image stabilization; Focus may need adjustment; Pricey

I am still on the fence for this lens. It might be because I love my 28-35 1.8 so much that I need to give it a chance

Sharp; fast; build quality; much better than the 24-105

Now this is a heavy lens, tripod foot but I learned to live with it, hoped it would be as great as my 18-35 1.8 but no not quite; Did I mention heavy No OS

The Sigma 50-100mm F/1.8 DC HSM Art is an interesting proposition. It's almost like three or four prime lenses in one (50mm, 60mm 85mm and 100mm), but with the added bonus of offering a wide f/1.8 aperture - something which you won't find in 100mm prime lenses.

With a focal range that covers many popular prime lenses and a super-fast maximum aperture, this lens is sure to appeal. For the cash, prospective buyers will get a well-built optic that can really perform when wide-open, particularly at 50mm.