Most practical ultra-wide ever!

A quick look at the Sony Zeiss 16mm-35mm f/4 FE

A new ultra-wide angle lens breaking the water surface is not huge news these days. If you remember getting excited about a zoom lens that offered a focal length as low as 28mm, you’re probably getting wrinkly like me. When Nikon exploded the F system bomb on a totally unsuspecting photographic world in 1959, it had the wisdom to offer a complete line-up of lenses. These ranged from an impressive 1000mm to 21mm super wide-angle. Apart from a few long focal length zooms of dodgy quality, there were no zoom lenses of any note for many years, and certainly none that extended into wide-angle regions. That is why, for the better part of half a century, the notion that zoom lenses would never be as good as a prime, single-focal length optic was a very firmly rooted prejudice.

Well, we had to wait until 1993 before super wide-angle lenses turned up. It was not for want of trying. Even for Nikon, optics such as 35mm – 70mm of various apertures, a cute little 28mm – 45mm were optically pretty unremarkable despite very modest zoom ranges. Technically the hurdles to designing a wide-angle zoom for SLR cameras are high and numerous. The difficulties were computational because of the number of different elements needed to solve many problems of curvature of field, spherical aberration, coma, fall-off and so on. Then there are deep mechano-optical problems because so many glass elements need to be carefully coated and the groups need to move with very high precision so they had to be carefully centred and controlled with high-precision cams. And if you wanted high speed – important not only for viewfinder brightness but to improve the focusing accuracy when auto-focus came along – the natural solution was to use big chunks of glass in front: heavy and expensive. (There’s another approach, but that leads to large and long lenses such as the huge Nikon 14mm-24mm).

You get the picture

So when the Nikon 20mm – 35mm f/2.8 was announced, the industry reeled for a moment, then within weeks, every well-heeled Nikon photographer had one loaded into their camera bag. Before long, photographers were expressing gratitude that the lens covered the focal length range at all – a polite way of saying its optical performance (particularly at full aperture and regarding its poor control of veiling flare) was less than remarkable. It reinforced the notion that zoom lenses would never match their prime lens counterparts. Canon soon responded with its first 20mm-35mm f/2.8 lens. It was beautiful, it was big. And it was horrible at close ranges, while its poor full aperture performance was reflected in the difficulty in focusing it. Finally, both Nikon and Canon came up with 16mm-35mm f/2.8 zooms that were premium grade, premium priced and offered excellent image quality.

New paradigm

All this is preface to the Sony Zeiss 16mm-35mm f/4 FE lens which I’ve used for a couple of weeks now on my Sony A7r, and I’d like to share the experience.

I’ll give you the bottom line now

Excellent handling against strong backlight.

To date (late 2014) it is the most photographically practical ultra wide-angle zoom lens ever made. If you want a high-quality zoom lens that covers the range 16mm to 35mm that is compact and light, which produces sharp and contrasty and richly coloured images, you’ll find it in this optic. On top of that it’s beautifully made, with the best focus movement I’ve felt in a very long time.
Now that you don’t have to skip to the end for the conclusions, let’s start again at the beginning. The Sony Zeiss 16mm-35mm f/4 FE lens for Sony A7 series and NEX became available around the 2nd week of November 2014. For anyone used to the 20mm-35mm or 16mm-35mm lenses from Nikon, Canon or Zeiss, the new lens comes over as remarkably petite and light. Its maximum aperture is f/4.
Like many, I also thought that was a disappointing max ap. Then I remembered that in all the many years I have used the Canon 20mm-35mm, then 16mm-35mm f/2.8L lenses, I never, ever used them at full aperture. Oh, perhaps a few occasions when the light was low – those being in the days of shooting film when stuck with 100 ASA transparency. In fact, the f/2.8 aperture was desirable largely because it gave a bright viewfinder image. Now, as the Sony A7 series cameras use electronic viewfinders, the brightness of the image transmitted by the lens is immaterial. We could use a lens with f/8 maximum aperture, and the viewfinder image would look the same brightness as an f/2 lens pointed at the same scene.

The impact of the EVF on lens design is one aspect of a new paradigm.

Another aspect is that the flange focal distance in the Sony A7 series is very short. This means the lens design constraints that once shadowed the lives of optical engineers are now removed. Formerly, engineers had to keep lots of room between the back of the lens and the film or sensor to avoid it being whacked by the mirror as it flips up and down. For very short focal length lenses, that is a pain because you have to design optics in which the image is projected from behind the lens using the configuration called an inverted telephoto. But now, without a mirror in the way, engineers can poke the back of the lens as close to or as far from the sensor as they like.

Smaller is better

All this pulled together means that Sony and Zeiss engineers have made a lens significantly lighter and more compact than the competitions’. At 72mm, it uses a smaller filter than the 77mm filters of the Nikon and Canon 16mm-35mm f/4 lenses. It’s not much slimmer with a maximum 78mm girth compared to the 82mm and 81mm of Canon and Nikon respectively. Having said, that, nearly half its length is less than 70mm in diameter, which makes a difference. Also it’s usefully shorter at 99mm overall compared to 113mm and 125mm (all without lens hood). Best, it’s only 518g against the 618g of Canon and the whopping 680g of Nikon. Yet the Zeiss is all-metal in body construction too. And forget the f/2.8 lenses: the Zeiss 16-35mm f/2.8 is a stellar performer, but it is too large and heavy to be fun to use.
Furthermore, don’t forget the Sony A7 cameras are less than half the size and weight of Canon, Nikon or other cameras with similar capabilities. As mentioned earlier, the Sony flange focal distance (from mounting surface of lens mount to focal plane) is very short: only 18mm compared to 44mm of the Canon EOS and 46.5mm of Nikon F. The sum of petite lens plus petite camera equals a tight, compact and highly manoeuvrable photographic instrument.

100% view of the foliage showing good subtlety of colour as well as fine detail, even with narrow items like branches against the light.

Better feeling

Better than the sheer size of the lump is how it feels when working. It features semi-matt surface of high quality common to other high-grade Sony lenses. I find this gets a bit slippery in hot conditions, when your hands are sweaty. Changing lenses while on a shoot in Singapore needed special attention, which is a bother I don’t need.

Of the two rings, the nearer ring controls zoom setting. It is broader than the other, moves very smoothly and is almost perfectly evenly weighted – i.e. needs the same amount of force to move – throughout the movement. The lens is most compact at the 35mm end and extends only about 16mm to reach the 16mm setting, causing a small but not troublesome change in balance.

The focus movement is first-rate: perfectly loaded, freely rotating and without any slack or play, i.e. the ring turns without any part of the movement unengaged and having no effect smooth. Its free movement can be unnerving for those used to an infinity stop. Also there are no distance indications. This means the lens is a ‘fly by wire’ optic: the focusing movement is not driven by your movements directly but your turning the collar sends signals that actuate a motor that drives the focus mechanism. Unlike many designs of this type, this lens responds immediately to a touch of the collar: excellent feed-back due, I guess, to successfully minimised induction time or a very rapid polling rate. Naturally this ring does not rotate during auto-focusing.

But, and a big but, cosmetics has ruled too much. The minimal styling results in very clean and sleek lines but the rings feel exactly the same until you move them, so there’s room for error. I’d prefer that the rings carried distinctly different textures e.g. ridges of one could be half the frequency i.e. twice the thickness of the other.

Upper mid corner of Queens Wharf at 100% showing rewarding richness of detail.

In use

Optically this lens is a fine performer. Of course sharpness dropped towards the corners, light fall-off at the image circle periphery was visible and as was very slight geometrical distortion. So, if you have to photograph paintings in narrow corridors – you will need flat field, even sharpness, no distortion plus even illumination  at the focal plane then this lens is not for you. Actually, no zoom lens I know of will be suited for that kind of work but the way lens reviews dig into corner pixels could make you think all lenses should be designed for copying paintings.

But for 99.9% of photography – for pictorial and documentary work, landscape and travel, it’s a superb lens. Actually, I thought distortion levels were well low enough to be acceptable for general architecture and interiors, and certainly for almost all urban photography. If you really need straight lines, just stick to prime lenses designed for the job.

In more detail, I compared the 16mm-35mm with my Zeiss 24mm-70mm f/2.8 lens at f/4 and f/8. The 16mm-35mm was a touch less sharp than the 24mm-70mm at 24mm at both apertures but this was visible only at about 500% magnification. At 35mm, the 16-35 lens was, to my surprise, a little sharper than the 24mm-70mm. This means the new lens is entirely usable at full aperture if you have to, but stopped down its performance is certainly good enough for me.
The most significant advantage of the wider zoom was that it held focus very well which makes it useable for filming. The 24-70mm lens is poor at holding focus, making it useless for zooming during a filming take (an issue I hope is addressed in the new version that’s rumoured to be coming).

This lens offers built-in optical stabilisation to reduce the effect of camera shake on image sharpness. Given that it’s a wide-angle lens and the A7 cameras do not suffer from mirror slap (although some think the A7r rattles a bit), the OSS probably lets you get away with an exposure time of around ¼ sec at 16mm and ⅛ sec at 35mm. At any rate, OSS adds a useful, practical feature to the package.
Auto-focus was rapid, and silent. At 16mm and in the dark, there was a little hesitation, but overall the speed feels to me to be very useable. Mind you, this is on my A7r which is slower to focus than the A7 and A7s. So I’d expect even better performance on these cameras.

Bottom line

This lens is clearly a top-drawer optic – little blue Zeiss plaque or not – and attracts a price of about USD 1400. I will adopt it as my wide-angle zoom for the next big travel and look forward to doing some serious work with it.

More pictures: added 16 December 2014

2 Responses to “Most practical ultra-wide ever!”

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