Rokinon 14mm F2.8 AF Sony E Review

Sony's full-frame mirrorless camera system continues to grow in popularity, and with that growth comes more robust third-party lens support.

Rokinon, a brand many photo enthusiasts know well, fills in a hole in Sony's first-party line with its 14mm F2.8 AF Sony E ($899), an ultra-wide prime with a bright f/2.8 aperture.

Its performance is surprisingly underwhelming, however, as it isn't sharp unless stopped down.

If you have the budget, you'll get better results from the Sony FE 12-24mm F4 G or the Sigma 14mm F1.8 DG HSM Art

Design: A Compact, Full-Frame 14mm

The 14mm ($549.00 at Amazon) is surprisingly small given just how wide of an angle it covers, and the fact that its image circle covers a full-frame sensor.

It measures 3.8 by 3.4 inches (HD) and weighs 1.1 pounds.

The barrel is metal, although the integrated lens hood and slip-on cap are plastic.

Despite having a relatively flat front element, there is no thread for lens filters.

You can get a holder for glass filters from NiSi for use with the lens.

Rokinon doesn't advertise any sort of weather sealing.

This isn't a surprise, given that the 14mm F2.8 is meant as a lower-cost option when compared with pricier first-party models.

But if you're used to taking your a7 or a9 series camera out in the rain, make sure you pair it with a lens that offers dust and splash protection.

Aside from the manual focus ring, the 14mm has no sort of physical control switches.

You'll use the camera body to change focus modes, and there's no in-lens stabilization.

Most full-frame Sony cameras offer in-body stabilization, which effectively smooths video footage captured with the 14mm prime and lets you snap blur-free handheld shots at longer shutter speeds.

Autofocus works, but it's slow.

On the a7R III with which I tested the lens, the focus requires 0.4-second to lock on.

All focus modes work, and EyeAF locks onto subjects eyes or faces.

When shooting stills, the AF-C setting was quick to recognize an out-of-focus scene, but it faltered a bit when recording video.

Using the camera's rear AF-ON button brought the scene into clear view, but it's a problem that most of the native Sony lenses we've tested don't have.

The manual focus ring turns freely.

It's bare metal, finished with a ridged texture.

Focus is electronic, so you'll need to turn the ring very slowly in order to make minute adjustments, or more quickly to move from extremes of focus range in a speedy manner.

Focus is available from 7.9 inches (0.2-meter) through infinity.

There are macro lenses in this focal range—you can use the Venus Laowa 15mm f/4 1:1 Macro with a Sony camera via an adapter.

At best the 14mm F2.8 AF magnifies subjects at 1:6.6 life-size.

Image Quality: Soft, Especially at the Edges

I tested the 14mm F2.8 along with the 42MP a7R III ($2,798.00 at Amazon) and Imatest software.

At f/2.8 it nets results that are very soft, scoring 1,660 lines on our center-weighted test.

With a camera with as many pixels as the a7R III, we require an image to notch 2,750 lines to be considered sharp.

The 14mm doesn't get there at f/2.8, even in the sharpest, central area of the frame.

Its resolution drops as you move toward the edges, showing just 984 lines at the periphery.

See How We Test Digital Cameras

At f/4 the resolution jumps noticeably to an acceptable 2,771 lines on average.

The central area of the frame is quite strong at 3,783 lines, but image quality doesn't hold up as you move away.

The mid parts—the third of the frame in between the center and edges—show a soft 2,262 lines, and the edges drop down to 1,512 lines.

The lens continues to improve as you stop down, with good quality through most of the frame at f/5.6 (3,174 lines), but edges that still show just 2,000 lines.

The 14mm F2.8 AF struggles even at f/8, where most lenses are crisp from edge to edge.

The average score is quite good, 3,460 lines, but edges still show a just-okay 2,473 lines.

You'll want to shoot at f/11 to get images that are crisp from edge to edge.

The average score is 3,757 lines, and even the very outer parts of the frame show 3,328 lines.

Diffraction starts to cut into resolution at f/16 (3,500 lines), though the effect is not overwhelming.

Avoid f/22, as the lens drops to 2,626 lines there.

Flare is a concern with wide lenses, as landscape shooters may struggle to keep the sun out of the frame, or may want to incorporate it in order to make a more dramatic exposure.

My shots with the sun in the frame show the 14mm AF has a tendency to capture flare.

The effect is most pronounced as you stop down, with the greatest flare visible around f/11.

The photo above, shot at f/8, is one of a sequence taken at each full stop, and while the effect at the bottom left corner is less pronounced at f/2.8 and f/4, it's still quite visible.

It's not something you're going to get with every shot that incorporates the sun, but it's something to watch out for.

There's quite a bit of barrel distortion, about 5.3 percent according to Imatest.

That's slightly more pronounced than the Sigma 14mm F1.8 DG HSM Art—a lens originally marketed for SLRs that is now also available in a native FE mount.

Thankfully it's one aspect of image quality that is rather easily corrected.

Adobe Lightroom includes a tool to straighten the curved lines it creates.

The 14mm draws images with a heavy vignette.

It's more noticeable if you shoot in Raw format, or have disabled Shading Compensation in your camera menu.

Uncorrected we see a -2.7EV drop at the corners at f/2.8, which drops to -1.8EV at f/4 and -1.5EV at narrower f-stops.

If you shoot in JPG format with corrections enabled it's less of a concern—there's a very modest -1.1EV drop at f/2.8 and at narrower settings we see negligible dimming, less than -0.5EV.

An Affordable Ultra-Wide Alternative

There are a lot of things to like about the Rokinon 14mm F2.8 AF Sony E.

Its size, bright aperture, ultra-wide angle of view, and autofocus capability are all pluses.

But the lens just doesn't measure up.

It's soft across the frame at f/2.8, and doesn't really shine until stopped down all the way to f/8.

There's the worry about flare, and the autofocus is slow in general.

There are better lenses out there, but not too many that sell for this price.

The 14mm F2.8 AF is priced at $899, and typically sells for less.

if you can get it on sale, and understand that you won't get stellar results shooting at wide apertures, you may want to consider adding it your bag.

But if you can stretch your budget, there are better options out there.

The Sigma 14mm F1.8 DG HSM Art is one—it's an optical gem in comparison, although one that's bulkier and priced at $1,600.

Sony's FE 12-24mm F4 G zoom is another pricey alternative, but nets you the convenience of a zoom lens in addition to delivering noticeably crisper photos.

Thanks to Lensrentals for providing the camera and lens for this review.