CZ 16-80 vignetting at 80mm: normal or defective?

[springm]

Returning from my China trip, I found a number of shots done with the 16-80 with visible vignetting. Closer inspection revealed, that those were not widest angle ones as I would have expected, but the ones at 80mm with f 4.5. Test shots look as following:

80mm, f4.5, manual focusing to infinity

80mm, f8, manual focusing to infinity

No processing was done except change of size, camera settings are neutral, sharpening +1.

Is this heavy vignetting normal for this lens, or is my specimen wrong?

Markus

[aster]

Hello,

I never experienced this with my CZ 16-80mm, especially at 80mm. Even at 16mm I don't get it in my latest shots.
(My lens was bought only very recently)

Yildiz

[springm]

Yildiz,
would you mind to do a test shot under the same conditions as I did: f4.5, focusing to infinity, a white wall or door as target?
I guess indeed my sample (bought 5 weeks ago) is defective, but to get it exchanged I might need some proof.

Best regards - Markus

[aster]

Yildiz,
would you mind to do a test shot under the same conditions as I did: f4.5, focusing to infinity, a white wall or door as target?

Certainly Markus,

I'll try find a white surface first to repeat your settings as you provided for 80mm. Right now all my surroundings are gray cement colour as I was shooting a construction-in-progress.

I hope to be back with some samples soon..

Yildiz

[aster]

Hi Markus,

Depending on the surface or maybe light source I had different results but there are some shots that give very similar results showing significant vignetting with the settings you used.

Settings used respectively are:
Camera:A100
Focal Lenght:80mm
F-Number:8
ISO:400

Second attachment:
Camera:A100
Focal Lenght:80mm
F-Number:4.5
ISO:400

Here are my results for white surface:

[David Kilpatrick]

Yes, it's normal, and applies to the 16-105mm as well, and most similar lenses - vignetting at the tele end is as common as vignetting at the wide end, but for different reasons.

It is only visible under very flat conditions like grey walls or white sky underexposed.

David

[Dr. Harout]

.... and sometimes blue sky (16-105)
But since I can fix that with ACR/LR then I will not complain (yet).

[springm]

Yildiz, David, thanks for test and replies.

On the one hand it is reassuring to know that the lens is not defective, on the other hand this amount of vignetting is disappointing for a lens of its price class, and it is only a minor consolation that the 16-105 does it, too.

The sharpness of the 16-80 is really good, built quality is so so, and vignetting is so so also. As the latter can be compensated electronically, the pro argument still outweighs everything else including the high price.

Markus

[aster]

You're welcome Markus,

I do understand your thoughts concerning this lens' quality versus price range. I'm quite thankful that mine has a good structural quality and is capable with some good optics.

I'd like to add a little detail about my tests above. Maybe not significant to others but I actually could see the amount of vignetting the aperture value would yield when I was looking through the viewfinder while taking the test shots. The shading at the corners would decrease or increase depending on the aperture.

Just wanted to note this: You can prevent the vignetting from ruining your photo just by looking through the viewfinder and maybe mimizing the aperture accordingly before releasing the shutter.

Yildiz

[springm]

Just wanted to note this: You can prevent the vignetting from ruining your photo just by looking through the viewfinder and maybe mimizing the aperture accordingly before releasing the shutter.

Yes, and this effect is the reason why it showed only on a small number of shots. But when you already are at ISO 1600 because it's so dark, you just have to accept the vignetting in order not to ruin the shot by camera shake. So this vignetting definitely is insignificant in many situations, but when doing certain kinds of available light shots, it unfortunately will come to full effect, diminuishing the value of this lens for low light photography.

Just as an example:

This was shot early in the morning at Tiananmen square in Beijing, shortly before the flag ceremony.

Regards - Markus

[aster]

I see what you mean Markus,

But what looks more odd in the photo is the bright lights of the LCD screens on those shiny compact cameras against a sky-lit authentic Chinese architecture. Really contrasty!.. Yet, intereting the ceremony must have been...


Yildiz

[peterottaway]

I bought my A700 with the CZ 16 - 80 mm lens as soon as they were available in this part of the world and given the horror stories doing the rounds I must have been lucky.

The lens is so frustrating in that it is not only sharp but also is able to pull the colours in the landscape here so well. But then there are the problems....... !

My only suggestion is the advice I was offered years ago but found difficult to practice when actually taking pictures (aren't zooms so convenient ), don't compose your photo too tightly in the viewfinder. Give yourself some editing room when you get back home and bring up the shot on the screen. That and use the best F stop that your experience tells you to use.

This is at best only a partial solution and when traveling you often have to grab the scene the best you can as it appears.

[springm]

But what looks more odd in the photo is the bright lights of the LCD screens on those shiny compact cameras against a sky-lit authentic Chinese architecture. Really contrasty!.. Yet, intereting the ceremony must have been...

Yes, this surreal scenario when standing in the crowd and the event is mostly visible in the screens of the persons standing in front of you, that is what drew my eye and what I tried to capture later on. The vignetting of the lens was only discovered when editing the pictures, and frankly, for this scenery it does not matter too much.

It's just that discrepancy of Zeiss glass and such anomalies, I simply had not expected this.

Markus

[aster]

It's just that discrepancy of Zeiss glass and such anomalies, I simply had not expected this.

Markus

Personally, I have this hope that Sony and Carl-Zeiss will address the optical and constructional defeciencies of this very nice lens by introducing a new version in the future. Many lenses went through changes/improvements in the last few decades in due course of new technologies that enabled the design of breath-taking cameras. So whyever not for this lens? If such a new CZ 16-80mm is devised in the future, they may even propose to replace ours with the new ones for a small price difference. Such an approach would mend many broken hearts over the CZ 16-80mm. Or there can be two different lenses, one being superior to the other, like the G lenses are superior to non-G lenses at this time.

Yildiz

[peterottaway]

Sony must be aware of the problems. That at 16mm and f 4.5 this occurs and at 70mm and f 8 then that occurs based on testing a random sample of lenses.

I think the very least we are owed at the present is a decent software program indexing known problems with the choice of a generalized auto-correct or a suite of manual tools to edit each picture.