why has the 16mm f2.8 got such a bad rep?

Started Jul 29, 2013 | Discussions thread
blue_skies
Senior MemberPosts: 7,051Gear list
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Re: Field curvature and camera behavior?
In reply to parallaxproblem, Jul 30, 2013

parallaxproblem wrote:

Mike Fewster wrote:

This lens was released with the very first Nex cameras. On those models, the lens had very soft corners. The reviews of the new camera and Nex at the time duely pointed this out and marked the lens down, although most said it was very good in the centre. Those reviews are still the reviews that people read when they look for evaluation of this lens.

These reviews are less than accurate on two grounds. The lens had highly variable performance with some copies much better than others. Clearly a quality control issue at Sony. Later releases of the lens tended to be considerably better. More importantly, on later Nex models, Sony changed the micro lenses in the camera and this made a significant difference to the edges.

There you have it, a later build lens on one of the later Sony models is much better than its reputation and an absolute bargain.

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Mike Fewster
Adelaide Australia

Not sure about all of this

- The soft corners and edges on the lens are a fact, even on good copies - every review comments on it and most sample images here and on other forums exhibit this property. Actually it doesn't bother me because that is the compromise you make for getting a cheap(ish) pancake wide angle, as long as the softness is equal in each corner (decentering is really annoying on a lens with this characteristic)

- Sony pulled the first review sample of the lens saying it was a 'pre-production' lens and that they had 'made changes to the manufacturing process' since then. This was almost certainly a lie or at least a distortion of the truth and what in fact they did was rather stupidly send out a bad copy for review. There simply is no way that they could have implemented changes and released the number of lenses they did into the distribution channels after the bad reviews... the review sample may even be the same 'pre-production' lens which is currently being used in Bremmen as a 'reference' to reject returned lenses (like the copy I sent back to them)

- Are we sure there are 'early' and 'late' releases of the E16/2.8? Are we even sure that the lens is still being produced or that there was ever more than the initial production run? I don't have the impression that Sony use JIT when manufacturing their NEX lenses so perhaps (this is what I suspect) they just produced a large number of lenses at the start, then realised they didn't make them that well and that the design itself was compromised (remember that they didn't believe enthusiasts would be buying NEX when he range was released so perhaps thought their customers would accept lower quality optics) and have been selling out of that initial stock since then, which is probably running-down now. The E16-50 has replaced the lens in providing a small pancake of that range, and the 10-18 zoom covers the same range as the UW converter and makes more money for Sony when people buy it (price-owch!)

If you have a good copy of the lens you can be happy, but finding one is not easy as there are clearly more bad copies than good ones on the market

You are sure about this? Evidence, link?

The E16 suffers from noticeable field curvature. If you want to see evidence of this, shoot a scene at f/2.8 and focus on the center, then focus on the corners. In the first shot, the corners will be soft, in the second shot the center will be soft.

If you combine the iAuto mode on early, and current, Nex cameras, while framing an image, you may see that the camera first opens to widest aperture, and then begins to increase the ISO. This means that, when using the E16, many pictures will be taken at f/2.8 and low ISO. Add field curvature to this, with focus on the center (or worse -CDAF- on contrast in the background), and nearby objects in corner will appear quite soft.

If the lens have been an E16/f4.0, the problem could have largely been mitigated. After all, most of the UWA lenses are slowish. The E16 would have been no exception.

The examples that I have seen (including posted here on this forum) that are bad suffer from decentering, not from corner softness. Corner softness is partially the photographers doing, not the lens. The QA complains were related to the decentering - easy to see as an entire side of the image will not reach proper focus - at any distance from the camera. Such problems seem to be an exception, rather than the rule.

i have two E16 lenses and both behave very similarly. Still, comparing them is tricky, as even the slightest focus shift can change the details in the corner, especially if objects in the corner are quite close.

The APS-C format, at 2:3 ratio, stretches the lenses in the long end. If the format was cropped (e.g. m43 size), the lens would have been significantly better received.

It is also the only E lens that can typically be purchased new at half price. And for $150, this is a remarkable impressive lens, if you use it with some thoughts - leave iAuto, stop down the lens, tolerate higher ISO.

Below is a typical result: with the fisheye adapter (exaggerating the soft corners), the camera selects 1/60th at f/2.8 and ISO 400. The shot is OOC JPEG, unmodified. Look at the near corners and see how fuzzy the floor becomes. But then also look at the upper corners, and notice that they retain sharpness (can be improved with PP).

Such an image I would not blame on the lens - here is a different one for comparison: look how the corners shape up at f/4 and a little more distance to the corner - both at 1/100s and ISO 100. The corners would have shaped up even more at f/5.6 and ISO 200.

E16 w/12mm UWA f/4.0 1/100s ISO 100

E16 f/4.0 1/100s ISO 100

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Cheers,
Henry

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