[toni-a]

16mm APS-C vs 18mm that's not really a big deal, also keep in mind that because of barrel distortions correction, both will be cropped so none of them has the theoretical view angle coverage.
and even 16mm isn't wide enough, consider on the wide end Sony 10-18f4 or Sony 11mmf1.8 and you are done, was going to metion tokina but surely you won't like size and weight

[stoppingdown]

Got the lens repaired. Now I'm curious to see whether the part replacement and recalibration fixed the decentering that was obvious since when I bought the lens — unfortunately it will take some time because we're going to have several bad weather days in a row.

What I can say now is that the repair shop told me the lens didn't suffer any mechanical shock — I was aware I never dropped it, but who knows — it broke by itself. In twenty-five years of photo equipment only the Nikon D70 did, but it was because of electronics.

[stoppingdown]

I ran a quick test in a hurry with bad light and no tripod (so it is just a preview), and left border is just awful. I really hope it's the test fault...

[toni-a]

Normally in Europe you have six months repair warranty, you can send it back for decentering repair

[stoppingdown]

If the problem is confirmed, I will.

[stoppingdown]

Ok, sunny day so I ran a test with the proper procedure. There is clearly a problem, even though is less severe than it seemed after my first quick test. Below a link to a comparison image with the borders a 23mm ƒ/8. Top row: test ran 9 years ago when I bought the lens; bottom row: test ran today. Same post-processing. Beyond the 16 vs 24 megapixels there is a clear difference in contrast due to the light (the old test was run in a crystal clear day of January, today it's hazy; there could be a slight impact of warm air blur, but not so much (20°C). I tried to compensate a bit the colour temperature to minimise the difference.

While the right border might be at the same level (I think most of what appears better in the old test is contrast, which is due to the different light), the left border has clearly a problem. It's less severe than I thought a few days ago because at first I concentrated to the dome only — which is terrible —, while the problem seems to happen abruptly precisely in the area of the dome (compare the two red stairs in the buildings behind the church: the right stair is considerably better). I must add that 23mm looks like it's the worst focal, so it might be impacted by a slight problem of focusing; but the sudden drop clearly is not related to a focusing problem. It is visible from 50mm down to wide.

Thoughts?

https://freeimage.host/i/Hgt8oRn

---

Here a second comparison screenshot including the center (the first image of each row) and where I added 30% more contrast to the new photos to compensate a bit the difference in light.

https://freeimage.host/i/HgtsQmN

[wim]

Personally, with edges like that I would return the lens without thinking even twice.

My 24-240 performs better than that.

Kind regards, Wim

[stoppingdown]

No doubts I'll resend it back to repair. I'd just like to collect eventual remarks before contacting the lab.

[toni-a]

I second WIM here, you paid big money to have your lens repaired, it's your basic right.
The problem they look at the viewfinder, they see a good photo, they say lens repaired and you risk having an answer that the lens is within their quality specs, you will have to insist.
It happened before with somebody here in the forum with a Sigma lens, he told his story here.

[stoppingdown]

The lens is going back t the lab.