Sony camera owners searching for a small, light lens should take a close look at the E 20mm F2.8 ($349.99).
It's an ultra-slim prime and captures a moderate wide-angle view when paired with an APS-C sensor camera like the a6400.
It's a much better performer than the older 16mm F2.8, and one of our favorite lenses for the Sony system in general, earning our Editors' Choice.
Ultra-Slim
The E 20mm F2.8 measures just 0.8 by 2.5 inches (HD), so it barely juts out from your camera.
Sony includes a compact plastic lens hood; it adds about half an inch to the height, and matches the barrel's diameter.
You'll need to remove the hood to add a filter—the thread supports the 49mm thread size, which is used by many of Sony's APS-C lenses.
There is no dust or splash protection, which is a feature Sony has reserved for its full-frame lenses to date.
On an APS-C camera, the E 20mm's angle of view is similar to a 30mm lens on a full-frame system.
It's a moderate wide angle, similar to what the main lens in most smartphones captures.
You can pair the lens with a full-frame camera too, either in a cropped mode that reduces the resolution and angle of view to match APS-C, or in full-frame mode.
With the latter, you get a dark frame, made by a baffle covering the rear element, around the edges of the image, as seen above.
Resolution drops significantly outside the APS-C image circle, so don't think of this as a full-time lens for a full-frame camera.
It does offer a little bit of extensibility.
Sony sells a 0.8x Ultra-Wide Converter for $159.99, which broadens the 30mm angle of view to 24mm.
You can also add the $179.99 Fisheye Converter for a more distorted perspective.
Manual focus is controlled via a ring at the front of the barrel.
It's very narrow, a fact necessitated by the overall slimline build.
Its size, coupled with how little the lens extends from the camera, makes manual focus a rather uncomfortable operation, at least when working handheld.
If you do go with manual focus control, the camera magnifies the frame and highlights the in-focus areas to help you nail the shot.
Autofocus is available too, and it delivers smooth, quiet operation, a plus for video as well as stills.
Focus is available as close as 7.9 inches, good for 1:8.3 life-size magnification at its closest working distance.
It's a little limiting, but given the size of the lens, it's understandable—lens elements move further away from the sensor to focus closer, after all.
The lens isn't stabilized, which isn't a surprise—adding optical stabilization tends to add a bit of size and weight.
You can pair it with the stabilized a6500, or live without the feature.
It's not a big deal for stills—you can easily snap crisp handheld shots with this lens without added stabilization—but we do see smoother handheld video results with a stabilized system than without.
Good Wide Open, Great Stopped Down
I paired the E 20mm with the 24MP a6400 for review.
The lens pairs well with the compact body, and while I tested the kit in the height of summer, I can see it being very good to slide into the jacket pocket of a winter coat.
The combination delivers solid image quality.
It's not the sharpest tool in the drawer at f/2.8, where we see 1,980 lines per an Imatest evaluation, but it's better than the 1,800 lines we want to see at a bare minimum.
Resolution climbs to 2,147 lines at f/4, which is solidly in our range for good performance.
There is a drop of clarity as you move away from center, so think about using a narrower aperture for landscapes and similar shots.
See How We Test Digital Cameras
At f/5.6 it shows a very good 2,238 lines, and it hits excellent territory at f/8 (2,498 lines).
Resolution is at its highest, and in our outstanding class for a 24MP camera, at f/11 (2,871 lines).
You can stop down as far as f/16, but resolution does take a slight hit (2,555 lines).
There is some barrel distortion, about 2.8 percent.
It's enough where you'll notice it in architectural images, but it isn't a big deal for for most shots.
There's a modest vignette at the corners, but it's not something you'll notice in most images.
If you do, both the vignette and the barrel distortion can be corrected using a lens profile in Adobe Lightroom, or manually using any basic image editor.
Small Wonder
If you're a Sony system owner and haven't yet added the E 20mm F2.8 to your kit, it's certainly worth thinking about.
The small prime offers a versatile angle of view—one that young photographers who cut their teeth with smartphone cameras will find very comfortable.
That it adds almost no weight to your camera and delivers very usable results wide open, and clinically sharp ones at narrower apertures, is a big plus.
It's where Sony's first pancake attempt, the E 16mm F2.8, falls short.
We would like to see Sony start to release APS-C lenses with weather sealing—it already offers bodies with dust and splash protection, and pairing a sealed 20mm pancake with one would make for an even better travel kit.
It's one area where Sony is well behind Fujifilm, which offers a number of sealed lenses for its APS-C mirrorless system.
That said, we're naming the E 20mm F2.8 an Editors' Choice.
Its size and weight are a big reason, but it wouldn't earn good marks if it didn't back it with solid image quality, which is certainly does.
The Bottom Line
The E 20mm F2.8 is the ideal wide-angle pancake lens for your Sony mirrorless camera.
