Camera Distortion?

[down2earth2]

This is a picture looking up a spiral staircase with a skylight at the top. The thing is, the spiral should be a perfect spiral, but it has some major distortion on the right side. Does this mean my lense is junk?

[PDG]

That's really, really weird for a camera. It might suggest the lens is warped on that side but I've never seen anything like it before. What kind of lens/camera is it?

[down2earth2]

It's a Nikon Coolpix 8700 I've owned for about 9 months. I've never noticed the distortion before, but maybe on ordinary photos without a clear pattern it's hard to see. I took 4 shots of the staircase and they all had the exact same distortion (the camera wasn't moved; it was on a tripod). I just went back and found another pic I took about an hour later. and I can't see any distortion. I guess I'll have to set up some test photos, or at least go back to the staircase and see what happens.

Here's the photo from an hour later. I sure can't see any distortion.

[PDG]

Yeah...this one looks good. Maybe the pattern itself messed up the camera. I've heard reports of certain patterns screwing up the camera's algorithm while it converts it to jpeg. Maybe that spiral did it. Or maybe there was a drop of water on the lens? I dunno...ghosts are my last resort.

[down2earth2]

Doh! I just realized that the way the camera is oriented for the photo above, the distortion would be in the blue sky. Could be a little hard to see. But here's a photo from this weekend. I chose this one because it has the window frame positioned where it should be distorted. Now I'm really perplexed.

I took the picture in Camera Raw (which I'd never done before, or since actually) so the compression in camera wouldn't be a factor. I don't see how shooting in Camera Raw could be the cause. There was no water anywhere around.

[PDG]

Wow...I'm just as confused as you. Anyone else want to take a stab at this mystery?

[Dave]

It's called berrel distortion

Read this .... http://www.dcresource.com/reviews/nikon/coolpix8700-review/index_pfv.shtml

A long way down the page you will find this :-

http://www.dcresource.com/reviews/nikon/coolpix8700-review/distortion.jpg

Hey, it's our brand new, heavy duty distortion test! With our new logo, as well, which will debut sometime this spring. Anyhow, the 8700 shows pretty mild barrel distortion at wide-angle, with no signs of vignetting (dark corners). Barrel distortion is most noticeable in tight quarters, or when you take pictures of things with straight lines (like buildings).

[TrinityOfOne]

Maybe try emailing a copy to Nikon support? I certainly haven't seen anything like that before, I wonder if it was the angle (I assume it was either straight up or down)?

[Dave]

The only other thing I thought it might be caused by was rising warm air currents, though I'd have thought it would have taken something pretty strong in thermal differences to create that much distortion.

[TrinityOfOne]

No, that's not barrel distortion, that's typified by a convex effect, like looking in a security mirror.

[Dave]

[QUOTE=TrinityOfOne]No, that's not barrel distortion, that's typified by a convex effect, like looking in a security mirror.[/QUOTE]
Well okay, I've heard of and seen straight lines making curves but not the other way round .... maybe I'll stick to my second theory then :)

[down2earth2]

Well I'm going to have to go back and retake the shot and see what happens. I don't know if I can get there today even though it's all of 8 blocks from home.

Dave, that was an amazingly complete review on the Coolpix 8700! Good find!

[Dave]

[QUOTE=down2earth2]Well I'm going to have to go back and retake the shot and see what happens. I don't know if I can get there today even though it's all of 8 blocks from home.

Dave, that was an amazingly complete review on the Coolpix 8700! Good find![/QUOTE]I was amazed at it's length .... and what a lovely if expensive camera too.

Suggestion ---- take the same picture with different cameras from the same spot if at all possible.

Answer = same result, then probably not the camera, test atmospheric disturbance by thermals.

Answer = different result, problem with camera. Sue the retailer and manufacturer!

:D

BTW if it hadn't been so distorted I'd have marked it much higher.

[down2earth2]

Well I finally got back to the library. Quickly set my tripod on the floor and took another shot up the spriral staircase. I took a quick look at the results and there was the same darn distortion.

Then I looked up at the stairs a little closer and it turns out not to be a perfect spiral. There's a few short sections of a flat landing instead of a consistant spiral. So it wasn't the camera that was screwed up after all.

Here's a somewhat blurry hand-held shot of the landing.

[PDG]

lol...very cool follow up. Thanks!

[dschmittle]

Try taking another picture with the camerra on a tripod pointing up again. i the problem returns it may be a lens that has loosened somehow and tilting slightly giviving the distortion. ???? I'd also go with the moisture on he lens thing also.


Dave

[Dave]

[QUOTE=dschmittle]Try taking another picture with the camerra on a tripod pointing up again. i the problem returns it may be a lens that has loosened somehow and tilting slightly giviving the distortion. ???? I'd also go with the moisture on he lens thing also.


Dave[/QUOTE]I think it was established that it was the building that didn't curve properly and the camera was not at fault in the slightest.