Richard Sibley tests the new Sony FE 85mm f/1.4 GM lens.
Sony FE 85mm f/1.4 GM – Image quality
The 85mm GM lens was obviously crying out to be used at f/1.4. It is probably between about f/1.4 and f/4 that this lens will see most of its use when shooting portraits, and you cannot help but be impressed with the image quality, particularly when paired with the Sony Alpha 7R II, as we did in this test. The depth of field produced at f/1.4 when shooting portraits is obviously very shallow, and when you combine this with a 42-million-pixel full-frame sensor, you need to make sure that your focusing is spot-on. It is the usual case that when shooting at f/1.4 the ends of the eyelashes can be sharp, but the eye itself is slightly out of focus owing to the limited depth of field. This happened a couple of times during our test, but it shouldn’t be seen as a reflection of the camera or lens – more a case of sometimes needing to stop the aperture down fractionally to create more depth of field.
When the shot is in focus, you really know about it. A 100% crop of a 42-million-pixel image is completely unforgiving, but the 85mm f.14 GM lens has nothing to hide. There is a staggering amount of detail. Every tiny texture of skin, every eyelash, the markings of pupils – everything is revealed crisply, even at f/1.4, which isn’t even the sharpest point of the lens. A little colour fringing from axial chromatic aberration is visible in out-of-focus areas, but it’s not particularly intrusive.
Indeed at the very centre the 85mm f/1.4 looks as good as the FE 90mm macro lens, which is one of the best lenses we have ever had through our test facilities. It actually raises the questions: how much of the 90mm technology is also in the 85mm lens? If the 90mm lens was to be released now, would it have the GM designation?
The graphs from our Applied Imaging tests show that the lens is impressively sharp in the centre of the frame at f/1.4, and gives exceptional results on stopping down to f/2. However when tested on the full frame A7R II, the corners are noticeably weaker, and you’ll need to stop down to at least f/4 if corner sharpness is desirable (it’s not usually important for portraits). As usual on full frame the very best results are seen around f/5.6-f/8.
Fairly strong vignetting is visible wide open on full frame, with the corners of the image around 1.4 stops darker than the centre. This is no bad thing for a portrait lens, as it can help to emphasise the subject. Stopping down to f/2 reduces vignetting to less than a stop, and by f/4 it’s negligible.
Our tests reveal that the 85mm is very well corrected for curvilinear distortion, with just a tiny amount of pincushion distortion detectable. This is exactly what we’d expect from a short telephoto prime, and it means that subjects should be drawn in a very natural-looking fashion.