Sony FE 50mm F1.2 GM
Sony’s largest-aperture prime is another gem from its G Master stable, as Andy Westlake nds out
After launching its original Alpha 7 twins in 2013, Sony initially had the nascent full-frame mirrorless market all to itself. It set about building a fairly conventional lens range, led by high-end f/1.4 primes and f/2.8 zooms. In 2016 it released the Zeiss-badged FE 50mm F1.4 ZA, but while we were blown away by the lens’s superb image quality, we couldn’t help but lament its excessive size and weight.
It wasn’t until 2018 that Canon and Nikon joined battle in this lucrative sector. Both highlighted the fact that their new mounts are much larger in diameter than Sony’s E mount, and suggested that this enables the design of ultra-large-aperture lenses. As if to emphasise the point, both rms also released premium 50mm f/1.2 primes ahead of f/1.4 designs.
Presumably stung by this attack, Sony has answered back with the FE 50mm F1.2 GM. Not only does it put to bed any suggestion that the E mount can’t support apertures larger than f/1.4, it does so with a design that’s smaller, lighter and less expensive than either Canon or Nikon’s offerings. In fact, at 87mm in diameter, 108mm in length and 778g, it’s barely any larger than the aforementioned FE 50mm F1.4 ZA. Its £2,100 price tag represents an £800 premium over its stablemate but is £200-£300 lower than its competitors. This all looks great on paper, but is there any catch?
Features
As part of the top-end G Master line, the new lens is designed to cater to the needs of the most demanding photographers. It promises high sharpness
along with smooth background blur, backed up by pro-level operability in a tough, weather-sealed package.
The rst thing you notice about the lens is the shallow convex pro le of its front element. Its 14-element, 10-group design employs three Advanced Aspheric (AA) elements to minimise optical aberrations and deliver maximum cross-frame sharpness. A compact 11-bladed diaphragm gives a circular aperture, which should help produce the kind of attractive bokeh that’s crucial to the appeal of such a largeaperture optic. To combat are and ghosting, Sony has applied its Nano AR Coating 2, while the lens is supplied with a sturdy bayonet- tting plastic hood. It employs 72mm lters, which is smaller than either its Canon or Nikon equivalents.
Build and handling
In design terms, the FE 50mm F1.2 GM boasts the same layout as the rm’s recent G and GM series primes, which means it handles really well. I tested it primarily on the Sony Alpha 7R IV and found the combination to be nicely balanced, thanks to the use of lightweight engineering plastics in its barrel construction. But it can feel more front-heavy on cameras with smaller grips.
Aperture control is provided via a traditional ring which clicks at one-third stop increments. If you prefer, a switch in the underside of the barrel enables clickless operation, which is desirable when shooting video. Rotate the ring past f/16 to its A position, and aperture control is handed to dials on the camera body.
Two AF-stop buttons are placed on the barrel, one for shooting in landscape format and the other for portrait. Their function can be re-assigned from the camera body. They click when pressed, which isn’t ideal for video work.
The large manual focus ring rotates smoothly without any end stops. Thanks to Sony’s Linear Response MF design, it provides a faultless focusing experience. With MF Assist enabled on the camera, it’ll automatically engage a magni ed view for the most accurate results.
Autofocus
Ultra-large-aperture lenses inevitably require a lot of glass, which in turn means they need to move large, heavy optical groups for focusing. In the past, this has often resulted in rather sluggish AF. However, Sony has harnessed four XD Linear motors that work in tandem to deliver impressively nippy autofocus, that’s also practically silent.
Perhaps the biggest advantage compared to using such a fast prime on a DSLR lies with the inherent accuracy of on-sensor AF. This means that there’s no need to painstakingly ne-tune the lens to match the camera body. Instead, I found that it delivered consistently sharp images, even when shooting at f/1.2 with subjects placed towards the corners of the frame. As a result, the lens is entirely straightforward to use.
The only real quirk comes when focusing on ne, close-up detail such as blossom. Here, I found the autofocus had a habit of snapping onto the background and being impossible to coax back onto the desired subject. In such situations, the remedy is to switch to manual focus.
Image quality
If you’re going to spend over £2,000 on a lens, it’s got to produce photographs that are worth the investment. Thankfully, the 50mm f/1.2 really delivers.
Close examination of images shot on the 61MP A7R IV reveals remarkable resolution in the centre of the eld at f/1.2. Naturally the corners aren’t quite as good, but there’s still plenty of ne detail, just at low contrast. Apply sympathetic sharpening in raw processing and you’d have to print extremely large for your images to look anything other than pin sharp.
Incredibly, the centre of the image becomes blisteringly sharp on stopping down to just f/1.4, at which point it’s as good as it’s ever going to get. The corners reach peak sharpness at f/4, with the lens then giving a superlative performance across the frame through to f/11. Slight diffraction softening inevitably becomes visible at f/16, resulting in similar levels of detail to those seen at f/1.2.
If you turn off in-camera chromatic aberration compensation, then a little red/ cyan colour fringing can be seen along high-contrast edges at the corners of JPEG les, but it’s really nothing to worry about. Normally it’ll be xed in-camera, while raw les include a
‘The centre of the image is blisteringly sharp on stopping down to just f/1.4’
correction pro le that’s applied automatically by Adobe software. Likewise, small amounts of fringing around out-of-focus areas can be visible when shooting at large apertures – a symptom of longitudinal chromatic aberration – but again it’s nowhere close to being objectionable.
A small degree of pincushion distortion is visible, with straight lines along the edges of the frame bowing inwards at the middle. This can be corrected automatically in-camera, but you’ll need a speci c lens pro le to x it accurately in raw. But with most images it’s unlikely to be troublesome anyway.
In fact the only real catch, if you can call it that, is vignetting. If you disable shading compensation in the camera menu, you’ll see about 2.3 stops of darkening of the corners of the image at f/1.2. This decreases progressively as you stop down, until it reaches approximately a stop at f/2.8, and then stays at that level through the rest of the aperture range. However, the vignetting pro le is gradual rather than abrupt, meaning that it’s not visually objectionable; in fact it’s just as likely to frame and enhance your subject as to detract from it. If you don’t like the effect, then leaving shading compensation turned on will reduce the fall-off to 1.3 stops at f/1.2, dropping to a barely perceptible 0.5 stops from f/2.8 onwards. Sony applies this correction to raw les as well as JPEGs.
Shooting wide open at f/1.2 gives startlingly shallow depth of
eld along with lovely painterly bokeh. Out-of-focus backgrounds remain attractive at smaller apertures too, with little hardening of the edges of blur circles as you stop down. Naturally though, you still need to pay attention to your backgrounds and what they bring to the image, rather than relying on the lens to blur them away. I saw no real problem with are even when shooting directly into the sun, which historically was a major problem for ultrafast primes. But the diaphragm’s 11 curved blades do result in slightly messy, indistinct sun-stars at small apertures. For those who are concerned by such things, plenty of other lenses are available for landscape work.