With another 4mm of focal length from the highly acclaimed 24/1.4 Art lens, Sigma gives landscape, architecture, astro and interior-shooters an extra wide coverage on full-frame bodies and still maintains its large f1.4 aperture. So for low light shooters, a lens that needs to be given a serious look at.
So I did... and what better a lens to take with me to photograph northern lights in the Yukon... I wish I had more time to do other photography with this lens, but i was leading a workshop in Whitehorse and only had three days to play with it photographing northern lights in Dawson City.
Lets start off with my conclusion first... saves you reading the whole blog ;-)
RUN, don't walk, RUN to the camera store and pick this lens up!!!!
Technical Specs of the lens
Size (diameter x length): 91 x 130 mm (3.6 x 5.1 in.). This is pretty large and it's surprising to see a 20mm lens being so long.
Weight: 944 g (33.3 oz.). Very heavy. It is much heavier even than the 665g of the already heavy 24/1.4 Art.
Optics: 15 elements in 11 groups. This is pretty complex design with 22 glass/air-surfaces and a lot of special elements including two aspherical elements. "Super-Multi-Layer" coating should reduce flare and ghosting.
The closest focus distance/max. magnification: 28cm (0.92ft.) / 1:7.1. With manual focus you are able to get down to 27cm which leaves about 9cm of working distance from the front of the non-detachable lens-hood to the subject. Magnification was then 1:6.5.
Filter-thread: There's no filter-thread. So you need to get some non-standard mounting system and a new set of filters
Build and Quality
The Sigma 20mm ƒ/1.4 Art follows the same design scheme and build quality we've come to expect from their newer Global Vision ART lenses. The build quality is fantastic. Constructed from their proprietary metal-like Thermally Stable Composite material, the lens feels very solid in your hands, something that i personally appreciate.
There is however no weather sealing on the barrel, but again, for me, while its a slant against the lens, i had no issues in -15C weather with snow falling on any of my outings.
I want to remind you about the new commitment to quality at Sigma. Sigma fans can feel confident knowing that every 20mm lens that leaves Japan’s factory has been tested using Sigma’s own modulation transfer function (MTF) measuring system.
Like the rest of Sigma's current Global Vision ART lenses, the new 20mm ƒ/1.4 Art utilizes their HSM (Hyper Sonic Motor) drive to power auto focus. The lens focuses very quickly, at well under one second throughout the full focus range.
Manual focus is also available, both with full-time MF override of the AF system or in complete manual focus mode using the AF/MF switch on the side of the lens.
To further customize focus options, you can always connect the lens to the docking station to fine tune adjustment to suit your personal shooting style.
At the end of the day, choosing a lens is really just about your personal needs and experience, and of course, the desired image quality.
This lens is heavy, yet engineered to perfection in my opinion. The focus ring is great, and I would rather shoot a heavy lens with a nice focus ring, than a light lens that is terrible to manually focus.
As far as image quality, this seems to be yet another fantastic Art Series lens from Sigma. And it doesn’t look like they are showing any signs of slowing down. Sigma now has full-frame, fast primes covering 50mm, 35mm, 24mm, and several mega-zooms, and now this awesome 20mm… who knows where they go from here... but i am eagerly anticipating the next launch.
Link to USA website http://www.sigmaphoto.com/lenses/wide-angle-lenses/20mm-f1-4-dg-hsm-a
Link to Canadian website http://www.sigmacanada.ca/lenses/sigma-art-20mm-f1-4-dg-hsm-lens--a20dghs/