For the past month, I've been testing the new Sigma 50mm f/1.4 DG DSM lens. Announced at the very beginning of the year and shown off at CES, it's been one of the best reviewed full-frame lenses released this year, and is the highly-anticipated successor to Sigma's 50mm f/1.4 EX lens released in 2008. That prime lens, if you recall, was the first lens I bought with my DSLR, the Canon 6D. It served as my primary lens for several months before I saved enough for some Canon zoom lenses. As I explained way back in Feb 2013, I opted to buy Sigma's f/1.4 over Canon's f/1.4 as my 50mm prime because it was just a better lens--more elements (8 vs 7) and more diaphragm blades (9 rounded vs 8) for sharper photos wide open and better bokeh, respectively. The tradeoffs were that at the time, the Sigma 50mm was $150 more than Canon counterpart, and weighed more as well. I thought it was worth it.
Jump forward to almost two years later and I actually rarely break out the 50mm anymore. For convention photography and events shoots for Tested, I keep my Canon 24-70m f/2.8 on the camera 90% of the time. The versatility of the 24-70mm range is too convenient, and I found that the most I would close down to on a prime is f/2.0--the depth of field at f/1.4 is a little too shallow for my taste. When I do need the sharpness and wide aperture of a prime lens, I borrow Adam's Canon 35mm. What I end up using the Sigma 50mm for are macro photos (eg. for sixth-scale figures), with a Fotodiox macro adapter attached.
But Sigma's new 50mm lens intrigued me. Instead of trying to be the best lens for the price, it follows along the path of Sigma's previous 50mm lens of trying to achieve the best image quality possible, no expense spared. On paper, that's a line of thinking that appeals to me: why not allow users to spend the extra money for the best product possible? Just as I didn't mind the 2008-model Sigma 50mm f/1.4 costing and weighing more than Canon's 50mm f/1.4, I figured I would embrace the new lens, even with its $950 price and 60% weight increase (815g vs 505g). Yeah, this single 50mm weighs as much as my all-purpose 24-70mm zoom.
Let's start with where this lens shines.