Sigma's lens options continue to improve, with speed and sharpness right up there among the best still lenses out there.
The new 20mm f/1.4 is no exception, and it continues the excellence of the Art series of lenses. The best part about this $900 20mm is that it covers a full-frame sensor, so it works perfectly on cameras like the Sony a7S II, which is exactly what Sebastian over at cinema5D recently did, testing the lens in some of the toughest moonlight conditions:
I shot everything in the Slog2 Gamma and graded the film with a “lowlight” LUT I created for this project, that retained most of the spectrum, lowered the dark areas and accented the highlights only slightl. I wanted to go for a low contrast look and I’m pretty happy with the result. I’ve heard otherwise, but personally I do recommend shooting lowlight in Slog2 as this for me is the perfect starting point for a balanced grade.
This is as much a camera test as it is a lens test, but both perform admirably here, and the lens seems to react well to the lights in the frame even wide open. While the image performance is stellar, Sebastian did have some notes on using the lens in a cinema application:
The focus can be set to manual and the lens has an analogue focus ring (unlike most Sony photo lenses). Unfortunately there are no hard stops making it hard to use the lens with any focus gears or focusing tools. Also the focus throw is very narrow and considering the lens has a thin depth of field it can be hard to focus manually at times. The lens is clearly design for the photographer in mind. This is a drawback we’re already used to as mirrorless and DSLR video shooters, but it’s not ideal for some applications and doesn’t provide the best ergonomics.
Having hard stops is helpful in a lot of situations, so it's unfortunate that this lens doesn't have any (like many of the Sigma lenses). That may be a deal-breaker depending on your usage, though it's worth noting that plenty of Canon still lenses do not have hard stops either.
Folks from Sigma have mentioned that they have no intention of developing cinema lenses, but these lenses, rehoused properly by the manufacturer, would be great for that purpose. You can get some rehoused, but at a significant cost increase. If Sigma went the route of Samyang's cine lenses, and not a complete rehousing, I'm sure they'd see quite a few sales, especially if the price was right. These stack up against the best lenses out there, so it's a shame we can't get them in a more usable cinema housing.
We'll see what happens in the future, but there's no question these are fantastic lenses, and can still work well depending on what you need them for. Be sure to head on over to cinema5D for more of this review.