AF-S 17-35: Recognise Light Fall-Off in the Corners

[je ne regrette rien]

Looking at this picture it seems to me that there are dark areas in the corners.

I don't remember whether the zoom was @ 17mm, nor whether I forgot to take the

UV filter off.

Anybody has any advice on this.

Thanks,

 

Luca

 

http://www.photo.net/photo/6523838

[ShunCheung]

I noticed that in your image, you specify that it was shot on an F5. But even on a film SLR, the 17-35mm, even at 17mm with a normal UV filter, should not have so much vignetting.

 

Perhaps your lens hood wasn't quite mounted correctly, although that seems uplikely since all 4 corners have vignetting. If the hood is mounted incorrectly, normally it should affect 2 opposite corners (diagonally).

 

I would retest it at 17mm with and without the filter and at f2.8, f4, and f5.6. Vignetting should decrease at smaller apertures (e.g. f5.6, f8).

[je ne regrette rien]

Thank you Shun. Looking at the picture there are also other erratic shadows on the wall which should not be there, since the lighting of the pictures looks very homogeneous.

Could it be the negative scan? Since I don't have a negative scanner myself, I ask the lab to do it, but the quality of scans is sometimes very bad (frame overlap).

[ShunCheung]

I don't see how film scanning can produce vignetting at the corners of an image. Typically the scanner sensors are on a straight line that sweeps across the image. The edges may differ from the middle, but the effect shouldn't be on the corners only.

 

Moreover, you can also inspect your negatives.

 

If you test again, I would test with slide film. Any traditional enlargement will involve the effect from the enlarger lens.

[bjørn rørslett]

Unless you shot at f/5.6 or smaller, a small(and generally harmless) amount of vignetting is inevitable on any wide-angle lens. If you had an underexposed shot and the lab tried to correct, this would lead to increased contrast and thus any tendency for vignetting would be visually exacerbated.

 

In technical terms, the presented photo does indeed look as if if derived from a bad original, or perhaps the scanner operator fell asleep during the process.

[Peter_in_PA]

"I don't see how film scanning can produce vignetting at the corners of an image."

 

I've seen it happen where the scan ENHANCED the vignetting.

[ShunCheung]

Peter, as Bjorn points out, vignetting can intensify if the contrast is increased during/after scanning, but I don't consider that as a result of scanning per se.

 

As I said earlier, if you want to test a lens with a film camera, I would use slide film and then inspect the slide itself with a loupe. Doing so you eliminates all factors from scanning and printing.

[je ne regrette rien]

Thank you, I will examine the negative more carefully, as well as the print I have.

I must say that the scan service is very, very lousy, often the frame is not correctly aligned, so that the alignment is wrong, parts of the photo miss or the scan includes the space between frames and parts of the previous or subsequent frame.

 

What strikes me are strange shadows on the picture: there should be no shadows on the museum wall.

 

But I will check and let you know.

 

Thanks, Luca

[jay_b6]

I think its just coincidental that the light focused on the painting is falling off right where vignetting would appear... and like others have said the scanning process may have introduced a bit more contrast.

 

no lighting system is perfect and you'll notice the falloff between the two paintings in the distance.

[jack_l3]

Maybe this is obvious, but if you use slide film, don't forget to have the film returned unmounted. Otherwise, you won't be able to see to the edges of the frame.

[frank uhlig]

If you can look at the negatives (no slide film needed), you will see vignetting right away and immediately, I assure you. No need for slides at all.

 

"But why not go to the hospital if a look in the mirror would clear it up" kind of overkill.

[je ne regrette rien]

Ok, Thank you all.

Actually there is vignetting. Is there a fault in the lens (which is new, bought in July 2007) or is it normal?

 

What shall I do?

 

- take off the filter @17mm

- stop down the diaphragm at least to f4 @17mm

- something else?

[ShunCheung]

Luca, as I said earlier, retest with slide film. Try both with and without the hood, without and without the UV filter and f2.8, f4, f5.6 and maybe f8, all at 17mm. Carefully write down each frame is shot under which conditions.

 

You can see vignetting on negative too, but it is easier to observe small problems with slide film. Our eyes and brain are not trained to observe colors and brightness in reverse on top of a brown color base, at least that is the case for the average people.

[Peter_in_PA]

Luca,

 

Take off the filter first, then stop down to at least f5.6 if you can at 17mm... You oughtta be

good. I bet taking off the filter makes a big dff. Whenever I shot that lens (on a full-frame

Kodak DSLR btw) I never noticed much vignetting, but the lens was naked most of the time,

or stopped down with a slim polarizer. I didn't use it much, but enough to know it was a

fantastic lens.