A 35mm f/1.4 prime lens is a go-to favorite for wedding photographers, street photographers and photojournalists alike. Empowered by its very wide aperture, it's a great story-telling lens that is able to be utilized with great effect in a wide range of situations.
If you're looking to purchase a 35mm f/1.4 prime in the near future, you may very well be stuck between two worthy contenders, the Canon EF 35mm f/1.4L II USM and the Sigma 35mm f/1.4 DG HSM Art lens. While they share the same focal length and f/1.4 aperture, there is one important differentiator between them. Read on to find out what that is.
First, let's start off with the Sigma 35mm Art. This is the lens that changed the market's perspective of what third-party lens manufacturers were capable of. Introduced in late 2012, it was sleek, stylish and featured fantastic image quality at an attractive price. The impact of this lens's introduction on the value of Sigma's brand cannot be understated; this lens shook up the industry.
How impressive was it? Consider this: Out of 320 reviews at B&H for the Canon-mount version (at the time of this post), 89.38% rated the lens 5-stars. Another 8.44% rated it 4-stars. The rest of the ratings (3-stars and below) make up the balance of 2.19%.
But for the purposes of this post, we're interested in how the Sigma 35mm f/1.4 compares to the even newer Canon EF 35mm f/1.4L II USM. While the Sigma had a sharpness edge on the original EF 35mm f/1.4L USM, Canon took the sharpness crown back with its introduction of the EF 35mm f/1.4L II USM. Both are very good, but the 35L II's corners are noticeably better. The Canon exhibits a little less distortion but doesn't fare as well as the Sigma in the flare department. With all things considered, I feel most will be happy with the image quality from both of these lenses. As such, we must look elsewhere for significant differentiating factors.
The two factors which seem to differentiate these lenses most are AF consistency and price. AF consistency can be mitigated; price, not so much.
First of all, Sigma has gone to great lengths to ensure its lenses will perform well in the AF department. They even designed their Global Vision lenses to be consumer upgradable via downloadable firmware and the Sigma's USB Dock accessory. The USB Dock can aid in dialing in focus at minimum focus distance, infinity and several points in between. The dock also provides a safeguard that Global Vision Lenses like the 35mm f/1.4 Art will play nicely with yet-to-be-released DSLRs (given time to develop new firmwares).
However, calibrating focus to maximize focus accuracy is one thing. Focusing consistently is another. I owned the Sigma 35mm f/1.4 Art for three years and used it primarily for weddings and events. I can say without hesitation that it did not nail focus as consistently with phase-detect (viewfinder) AF as my Canon USM lenses. The consistency wasn't bad, but the difference was noticeable. Thankfully, there is something you can do to significantly increase your in-focus rate.
If using the Sigma 35mm f/1.4 Art for an especially critical shot, Live View focusing can be utilized to ensure your subjects remain in focus. Because Live View uses the actual data processed by the sensor to achieve focus, any issues with traditional phase-detect AF are bypassed. It may look silly when you're holding your DSLR up like a compact camera, but... the in-focus result will likely be worth the small embarrassment for fleeting moments.
While Live View focusing for "can't miss" moments may be inconvenient, it will likely prove a worthwhile concession for many photographers considering the Sigma 35mm f/1.4's biggest benefit over the Canon 35L II – price. Without rebates or special pricing, the Sigma 35mm f/1.4 Art is half the price of the Canon at the time of this post. The Sigma is an incredible value, even when its primary drawback is taken into consideration. On the other hand, important to some is that the Canon has weather sealing to its advantage.
If you're a wedding/event photographer who wants the most reliable AF in a 35mm f/1.4 lens (or otherwise requires weather sealing), the Canon "L" is the best choice. It's an easy recommendation if one's budget allows for its acquisition. However, if your livelihood isn't dependent upon capturing fleeting moments with a 35mm focal length that cannot be recreated, or if Live View focusing is a tolerable solution for when the moments matter, then the Sigma 35mm f/1.4 Art can likely fulfill your needs at a very reasonable price.