[0.135 lb] The lens is sharp and easy to focus. Initial results are very good. I use it on a Canon 6D and a Sony A7R2 w/a Metabones adapter, and all automatic functions work fine with fast autofocus. The fast aperture combined with the Sony's in-body image stabilization yields very reliable, sharp results even in very dark conditions. It's big, but not as big as my Tamron 15-30mm f/2.8. The large aperture permits creative options not possible with other super-wide lenses I've used. In particular, I can do selective depth of field effects similar to what I've done with tilt-shift lenses. I plan to use the lens extensively for star field shots, but haven't had the opportunity to test it in that application yet. The lens feels very solid and well-built.

[0.135 lb] Compact and solid lens lives up with Sigma reputations.

[0.135 lb] Great product and speedy delivery.

[0.135 lb] I use with my Nikon D800E and works great, very fast focusing, awesome sharpness and beautiful bokeh, also have a really solid construction and great design, recommended for everybody, especially if have 30MP+ camera to unleash the true image quality of this lens.

[0.135 lb] petite faiblesse au niveau de l'autofocus: deux photos successives avec la mise au point sur le mme objet ont une mise au point diffrenteles photos de groupe sont magnifiques grce l'absence de distorsion, ce qui est rarement le cas avec les optiques trs grand angle.

[0.135 lb] Very nice lent

[0.135 lb] The lens is built like a tank. You get that impression when the package arrives, before you see it. It's heavy, solidly built and feels very good in the hand (it's nearly as heavy as the 70-200mm F2.8). With a lens that heavy and well built, you'd expect it to have great picture quality and...it doesn't disappoint. I've used the lens professionally for real estate photography and expect to use it on other projects as well. It's bright, fast and wide—perfect for architectural, landscape and night skies (I experimented just one night with a few pictures and wow! It's awesome). I've experimented shooting wide open at 1.4 - 2.0 and didn't see a noticeable difference in sharpness, although I preferred shooting at around 1.8 - 2.0. I highly recommend it!

[0.135 lb] Just received the lens so no time for full evaluation. I have had the HSM 20mm for Canon and have used on Sont A7r4 with Metabones adapter. I have enjoyed the HSM lens for use in low light but used sparingly due to weight and fear of damaging front element during casual use. I bought the DG,DN lens because I figured I would get to use it more often but did not consider the improvement in photo IQ or video performance. I saw a couple of reviews comparing Sony 1.8 stating the Sony was a little sharper and I was not expecting a large increase in the IQ over old HSM. I think I was wrong. So far with only about 100 test images, this lens appears to be a definite improvement over the HSM. New Lens also much better for video since no adapter needed. Very fast, accurate focusing improves IQ as well. Very impressed. Very happy so far. Plan to use new lens a lot especially in low light. Kudos to B&H for super-fast delivery!!

[0.135 lb] What else is there to say? The Sigma 20mm f1.4 Art is an ultra-fast, ultra-wide, ultra-well-built lens. The auto focus performs very well on the Lumix s5ii, and the flat front element allows for standard filters to be used.

[0.135 lb] Other than vignetting, this lens is a monumental step forward in 20mm lens technology! I also wish the lens hood were a little tiny bit smaller in diameter so it wouldn't be such a tight squeeze in my custom fit case previously configured to hold six A7R Mark IVa cameras and one A1, all with prime lenses mounted and with grips ready to grab and start shooting, all in a smaller case than a typical big backpack, small enough to fit into an ordinary fold up wagon and leave room for a basket of flowers and other props, plus lights!