Why do I have black corners in my pics?

[Chromo]

Hi - I was hoping someone could tell me why I'm getting black corners in some of my pics?

I was reviewing my pics from last weekend's trip to the Hunter Valley and noticed that some of my pics had black corners :(

I have a Nikon D70s, with a Nikkor AF 18-70mm lens. It seems like the ones I took from the hot air balloon were more likely to have the black corners, but a few other did too. I'm not sure what is causing it - I haven't seen it on my pics before and I can't think of any settings I used that I haven't used before.

Any help?
Here are two pics showing the black corners at the top:

[ilminsterpete]

Lens hood or a thick-rimmed filter in the way. If you zoom in slightly do the dark corners disappear?

[Nic076]

Yep - Peter is right that is how I sometimes get my corners.

[Chromo]

Lens hood or a thick-rimmed filter in the way. If you zoom in slightly do the dark corners disappear?

No lens hood. But I did have a skylight UV filter on, and a polarising filter on top of that - so that might be it. Thanks for the suggestion and quick response - I'll experiment and see if I can confirm it.
I don't know if zooming in slightly makes the corners disappear - I don't recall seeing the black corners when I took the pic, but it wouldn't be the first time I've taken a pic without scanning the entire scene carefully!

[ricktas]

Yep. stacked screw on filters will do it, especially at the wide end of your lens zoom range. You can either remove the filter(s), or zoom a bit to stop it occuring

[JM Tran]

bingo! there is your answer right there

u should not have had 2 filters on at the same time, it will lead to vignetting - which is what this occurance is called

having the skylight AND the polariser on at same time will degrade image quality, adds vignetting, and sometimes may confuse the metering system of the camera as there are more glasses affecting light in front of the lens.

[Chromo]

Thanks for the confirmation Ricktas, and thanks for the terminology JM Tran.

The camera salesman originally told me to buy the skylight filter and never take it off (it was solely to protect the lens according to the sales dude). I guess that means either removing the skylight filter or not using full zoom when I'm stacking filters. I'll do some googling and experimenting with both ways.

I think I love this place! Post a question and get helpful answers within an hour :th3:

[ricktas]

Re UV filters - have a read of this thread : http://www.ausphotography.net.au/forum/showthread.php?t=7832

[arthurking83]

Re UV filters - have a read of this thread : http://www.ausphotography.net.au/forum/showthread.php?t=7832

long story short!! remove both the UV and skylight filters. Both unnecessary obstructions that you don't really want to have to deal with.

Although!! after having a quick play with a friends new lens a few weeks back, which had a skylight filter on at the time, I did notice a nicer captured image straight off the sensor, not requiring any tweaking in PP. They were only quick fire test shots, but the skylight filter seemed to make a nicer rendition of the particular scene.
if you are into capturing the image as best as you can with as close to zero processing as possible, only use filters for an intentional purpose, such as skylight or CPL or ND/GND or whatever. Unless you are constantly at the seaside or other such harsh environment, you don't need it for protection.

[ricktas]

As has been said above Phil, in some HARSH environments a UV filter can be valuable, but its not necessary all the time.

[davesmith]

Regardless of opinion on whether you should use them or not, one other thing to remember if you do use them, and in particular stack more than one, is that you won't necessarily see the vignetting through the viewfinder when you take the shot.

Your camera's viewfinder only covers about 95% of the total frame so you'll probably only notice it after the shot as been taken.