What's causing my dark corners?

[MarlowTrips]

I took this shot the other day but I don't know why the corners are dark, especially in the top left? Any ideas? It was taken on my 400D with a Sigma 18 - 200 lens at 18mm, f3.5 and 1/250. ISO was 100.

Thanks in advance.

http://www.talkphotography.co.uk/gallery/data/500/Lens_problem.jpg

[foodpoison]

Were you using a circular polariser?


Vignetting.. Duh. :schtum::coat:

[Dan Leach]

Its caused by vignetting.
http://en.wikipedia.org/wiki/Vignetting

[zeroeseight]

It's most likely due to vignetting.

http://en.wikipedia.org/wiki/Vignetting

[oldgit]

.. or a lens hood

but more than likely its just a facet of the lens when it's wide at 18mm

[MarlowTrips]

Thanks for the quick replies! Yes, I was using a circular polariser, will that make the effect worse?

How can I avoid this in the future? Will a different aperture make a difference?

[oldgit]

Basically, yes any filter, CP especially, will make things worse.

What you are doing with an incorrect hood or filters is adding a tube to the front of the lens. With a long
enough tube you'll get a circular image

Usually you can get away with 1 filter, but CP's tend to be quite thick. In your case it looks like you see
the effect.

[dolomitefan]

Stopping down a bit say 2 stops will reduce the vignetting. Also it is fine to use a CP but don't stack it on top of your UV filter which I assume you have fitted to protect the front of your lens.

There's no advantage in using such a wide aperture in this shot anyway.

[theory]

I really like the vignetting!

[desantnik]

.. or a lens hood

My money would be on that...

[cherryrig]

It is must certain vignetting. It's because you have the lens on the widest setting 3.5. Stop down some and it will go.

[robbys82]

Theres quite a lot of programs that allow to you apply or remove vignetting. I use lightroom and it can probably solve that. Some photos I love adding it too though

[Ewan]

I really like the vignetting!

So do I! :clap: