A relatively lightweight lens for portraiture, weddings, sports
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Sony has just announced the FE 135mm F1.8 G Master (GM) lens, its 9th GM lens and 31st native full-frame E-mount lens. According to Sony, the GM line promises both ‘high resolution and exquisite bokeh’, and our initial impressions after shooting with the lens are certainly positive.
Sony tells us the design of this lens is new, and entirely different from the A-mount Sonnar 135mm F1.8 ZA lens. At 950g (2.1lb), it’s 280g (0.62lb) lighter than the Sigma Art 135mm F1.8 lens, which – at 1230g (2.7lb) – weighs 30% more than the Sony. That’s a significant weight difference, and the 135mm GM balances reasonably well on an a9 or Mark III Alpha-series full-frame body.
The relatively lightweight and portable nature of the lens will be appreciated by its target audience: portrait, wedding, and sports shooters looking for subject isolation and fast autofocus performance.
Optical design ensures smooth bokeh, minimal aberrations
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Comprised of 13 elements in 10 groups, the Sony FE 135mm GM features an XA (extreme aspheric) element, an ED (extra-low dispersion) and Super ED element. The Super ED and ED glass used in the front element groups replace traditional large and heavy negative elements commonly used to suppress longitudinal spherical aberration, which is most often seen as purple and green fringing in front of and behind the focus plane, respectively. Sony claims this combination of a Super ED and ED element ‘compensate for axial CA, minimize color fringing and maximize overall resolution.’
Onion-ring bokeh is non-existent
Meanwhile, the large XA element mitigates spherical aberration, and helps maximize sharpness. Sony’s 10 nanometer mold precision and other recent improvements ensure that onion-ring bokeh is non-existent. In addition, each XA element produced is individually inspected to ensure smooth bokeh and an 11-blade circular aperture ensures circular out-of-focus highlights even at F4 and beyond.
Flare resistance and ergonomics
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Sony’s Nano anti-reflective coating is used to reduce flare and ghosting, which can be particularly problematic when shooting backlit portraits. A fluorine front element repels fingerprints and water.
There’s an aperture ring with 1/3EV increments, as well as two custom ‘Focus Hold’ buttons that can be assigned to any one custom function (they can’t be assigned to different functions). The locations make them convenient to access with your thumb in either landscape or portrait shooting orientation. An AF/MF switch makes quick work of choosing between auto and manual focus.
Fast to focus
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The 135mm GM has a close minimum focus distance of 0.7m (2.3ft), offering 0.25x magnification. A focus limiter switch allows you to optimize focus for your shooting situation such that if you’re shooting mostly distant subjects, you can ensure the lens never hunts to a nearby distance. You can also choose a range from minimum focus distance to 2m (6.6 ft) if you’re only shooting close-up portraiture. With the right setting, you’ll almost never experience hunting to extremes, which can otherwise slow down shooting on such a shallow depth-of-field prime.
Two focus groups can move independently of one another in a ‘floating’ design for fast, accurate autofocus
Speaking of focus, four XD (‘extreme dynamic’) linear induction motors replace the previous piezoelectric design of Sony’s ‘Direct Drive SSM’ system. These motors are capable of moving larger, heavier elements, and it’s Sony’s first lens to feature four of them driving two focus groups. The two groups – one in the front and one in the rear – can move independently of one another in a ‘floating’ design, yielding fast, accurate and quiet autofocus (and we can confirm that in our experience, it’s the fastest focusing lens of its type). A new control algorithm helps ‘maximize control response and ensure quiet, low-vibration AF’ – we assume this is at least in part related to the lens’ ability to receive and execute instructions at the high rates the a9 is capable of (60 instructions / second).
Features video shooters will love
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The dedicated aperture ring is ‘de-clickable’, making smooth changes to depth-of-field in video possible. The focus ring offers a linear response in manual focus mode, making focus pulls easy during video shooting. The linear response will also be appreciated by stills shooters accustomed to the focus response of traditional DSLR lenses.
Magnesium alloy chassis, dust and moisture resistant
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Sony claims the 135mm GM lens has a similar kind of internal construction as on the FE 400mm F2.8 GM lens. It has a magnesium-alloy chassis, and Sony claims dust and moisture resistance. A rubber gasket around the mount helps keep water from entering your camera internals.
The FE 135mm F1.8 GM will ship in late April for $ 1900 USD / $ 2600 CAD. If you haven’t already, you can view our sample gallery here to get a better idea of what this lens is capable of.
Articles: Digital Photography Review (dpreview.com)