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

Started Jul 29, 2013 | Discussions thread
parallaxproblem
Veteran MemberPosts: 4,916Gear list
Like?
Re: Field curvature and camera behavior?
In reply to blue_skies, Jul 30, 2013

blue_skies wrote:

parallaxproblem wrote:

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?

Fair question

OK... I sent a very decentered copy (I mean really bad - about 15% of the right hand side never sharpened at f8, let alone the corners and peak sharpness significantly shifted from center to a point in approx 8 o'clock direction) back to Sony and they accepted that the issue was there but stated that their 'reference copy' of the lens showed even worse decentering. That says a lot to me!

We have plenty of comments from people on the forum who had to go through two, three or four copies of the lens before they found a good one. This seems to suggest a lemon ratio of over 50% on this lens. I have two copies of the lens and both are bad. I have had access to four copies of the 18-55 and only one was not so great (the other three were fine by my standards) and again there are reports of problems with specific 18-55's on the forum but never 'I had to try x copies before I found a good one'

Not 'scientific evidence' but I think sufficient to give some credence my statment

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.

Could be the case - but when I did my brick wall shots to check the lens out I tried changing the angle of incidence to the wall and didn't notice significant improvement in edge performance

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.

Never used iAuto but certainly the corner issues do get significantly better as you stop down. Corner sharpness of a non-decentered, good copy of this lens lens is not an issue for me. My problem is with decentering

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.

2.8 can be useful in low light, as long as you know how the lens behaves. I don't think Sony could have justfied an f4 prime lens in the market with the kit lens offering f3.2 at 18mm

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.

Comparing my two copies isn't too difficult. One is very badly decentered to the left and the other is only badly decentered to the right!

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.

Can't really see the point here. It's an APS-C lens and was (I assume) designed and then released as such

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.

Not in Europe it can't... Even second hand prices are greater than that

My local price comparison puts the cheapest at just under CHF300 (not in stock) and the in-stock price at CHF330, and that hasn't changed since the lens was released

Much too expensive for what it is IMHO. Have you seen the websites where they pull one apart? In spite of the nice metal shell, unfortunately the insides are, well, somewhat 'cheap':

http://www.lensrentals.com/blog/2012/03/unmaking-pancakes

Reply   Reply with quote   Complain
Post (hide subjects)Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark post MMy threads
Color scheme? Blue / Yellow