Sony FE 20mm f/1.8 G Review
The Sony FE 20mm f/1.8 G is a new ultra-wide-angle prime lens for the Sony Alpha full-frame mirrorless camera system.
It features 14 elements in 12 groups including including AA (advanced aspherical) elements and three ED (Extra-low Dispersion) glass elements, offers a minimum focusing distance of 18cm with a maximum magnification of 0.22x, and has a 9-blade circular aperture which creates an attractive blur to the out-of-focus areas of the image.
There's also a manual aperture ring that can be de-clicked for silent video shooting, a customisable Focus Hold button, Nano AR Coating to eliminate flare and ghosting, and the lens is also dust and moisture resistant.
The Sony FE 20mm f/1.8 G lens is available now priced at around £950 / $900 in the UK and the US, respectively.
Ease of Use
Weighing in at 373g, the Sony FE 20mm f/1.8 G is very light for an ultra-wide-angle full-frame lens that offers such a fast maximum aperture, and it's also compact too, measuring 73.5 x 84.7mm, making it smaller and lighter than the comparable Sony FE 24mm f/1.4 GM lens.
It's overall size and weight really complements a body like the Sony A7R III camera that we tested it with, as shown in the photos below.
Build quality is very good, not quite up to the standard of the flagship GM lens range, but not too far off. The Sony FE 20mm f/1.8 G has a sealed dust and moisture resistant design, although Sony stop short of saying that it's 100% weather-proof.
The Sony FE 20mm f/1.8 G lens has a metal lens mount. It accepts 67mm filters via plastic threads.
The lens has a fairly wide, ridged focus ring. Manual focusing is possible by using the focus mode switch to toggle between AF and MF.
There are no hard stops at either end of the range, making it a little more difficult to set focus at infinity. Polariser users should be pleased that the 67mm filter thread doesn't rotate on focus.
The lens utilizes not one, but two XD Linear Motors to provide quiet and smooth auto-focusing, making it very well-suited to shooting video, with the overall lens length remaining constant during focusing thanks to an internal design.
When it comes to auto-focusing, the Sony FE 20mm f/1.8 G zoom proved to be an almost silent, very quick performer on the Sony A7R III camera that we tested it with. We didn't experience very much "hunting", either in good or bad light, with the lens accurately focusing almost all of the time.
Sony's near flawless Eye AF worked perfectly with this lens, quickly locking onto and tracking the subject's eye despite the ultra-wide-angle of view.
The Sony FE 20mm f/1.8 G lens features an aperture ring that has 1/3EV stops ranging from f/1.8 to f/22 and an Auto setting.
The Click switch on the bottom-right of the lens barrel lets you select whether the aperture ring clicks into place at each aperture stop or rotates smoothly for silent operation during movie recording.
The lens also has a customisable focus hold button which keeps the lens locked to the current focusing distance, useful if you're auto-focusing and don't want the lens to try and find focus again. It can also, amongst other things, be usefully set to Eye AF.
The lens doesn't feature built-in optical image stabilisation, relying instead on the camera body's stabilisation system.
The Sony FE 20mm f/1.8 G lens is commendably supplied with both a soft case and a good quality plastic petal-shaped lens hood (ALC-SH162).
The 20mm focal length provides an angle of view of 94 degrees.
Chromatic aberrations, typically seen as blue or purple fringes along contrasty edges, were not really apparent in our test shots, only appearing in very high contrast areas. The 100% crops below show the worst-case scenario.
Light Fall-off and Distortion
With the lens set to its maximum aperture of f/1.8, there is some noticeable light fall-off in the corners, requiring you to stop down by at least 2 f-stops to prevent it. Barrel distortion is very well controlled for such a wide-angle lens.
The Sony FE 20mm f/1.8 G certainly isn't claimed to be a macro lens, but you can get pretty close to your subject thanks to a minimum focusing distance of 18cm, with a maximum magnification of 0.22x.
Sunstars and Flare
The Sony FE 20mm f/1.8 G produces very nice sunstars when stopped-down to f/16 and f/22, as shown below.
The lens is quite susceptible to flare when shooting directly into the sun, though, even with the supplied lens hood fitted.
Bokeh is a word used for the out-of-focus areas of a photograph, and is usually described in qualitative terms, such as smooth / creamy / harsh etc.
In the FE 20mm f/1.8 G lens, Sony employed an iris diaphragm with 9 rounded blades, which has resulted in appealing bokeh for such a wide-angle lens.
We do realise, however, that bokeh evaluation is subjective, so we've included several examples for your perusal.
In order to show you how sharp this lens is, we are providing 100% crops on the following page.