Is this photo tilting?

http://backup.cambridgeincolour.com/...7f1ba976_b.jpg

Hi,

Do you also have the feeling, that this photo tilts to the left? - I checked the vertical lines by putting a grid over the photo. It seems to be totally straight. :confused:

Could it be an optical illusion caused by the trees?

Regards, Henrik

Hi Henrik,

It's an illusion caused by the horizontal lines appearing to "drop" on the left hand side, but not being able to see a "counter balance" so much on the right.

I often have a similar issue with horizons in landscape images where the further the coast goes the higher they appear to be because they rise in the frame (due to the camera's elevation).

PS: Welcome to CiC - great to have you with us :)

It looks bigger at the top than the bottom. I have the problem of photo's that look like they are tilting but usually it is an object in the image that is.

@ Colin: Thaks for your welcome greeting!
I agree that the curved horizontal lines "does the trick" - and yes, the tree covers some of the right curves. But amazingly I also sometimes see the plant tilting to the right!

I don't follow you on your landscape images. Could you point to an example?

@arith: I would not think, that the plant is physically bigger at the top. But as the horizontal lines curve upward at the middle, the thing may look "thicker" at the top?

Puzzling photo :rolleyes:

- Did I do right in answering you both in one message - or should I rather reply to each of you?

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- Did I do right in answering you both in one message - or should I rather reply to each of you?

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Henrik
I think what you did is correct. In your message you identify to which person you are directing your answer. So, in one message we see your responses to each of the points made by other people.
If you answer each person in an individual message, it makes the Thread longer and less concise.

Yes there appears to be something optically strange about that photo. Initially I thought it was tilting to the right but after viewing it from an angle which was well to the left of my screen and then from well to the right it now appears square when viewed straight on.

And now it looks straight no matter which angle I view it; so there must be something psychological with that image.

It's probebly a lens distortion. A barrel distortion over the left side of the structure would distort the horizontal lines giving the effect you're seeing.

Had the structure been centered in the lens I doubt you would be having this issue. Try using a plugin to correct for the lens distortion.

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Originally Posted by Henrik

- Did I do right in answering you both in one message - or should I rather reply to each of you?

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Either way is fine :)

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Originally Posted by KentDub

It's probebly a lens distortion. A barrel distortion over the left side of the structure would distort the horizontal lines giving the effect you're seeing.

Had the structure been centered in the lens I doubt you would be having this issue. Try using a plugin to correct for the lens distortion.

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Interestingly Kent - when I opened the image in Photoshop and used a couple of guides, I was somewhat surprised to find that the verticals are as straight and perpendicular as a plum bob.

Sorry perhaps barrel was the wrong word. I've seen this issue when working on 3d animation projects. You are indeed correct, there is no horizontal distortion (vertical lines are stright). There is however, significant vertical distortion (horizontal lines arn't stright). The trees covering the bottom of the structure make it much harder to correct, since you can't trace the lines behind them.

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Originally Posted by Geoff F

(...) so there must be something psychological with that image.

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I couldn't agree more! :D :rolleyes:

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Originally Posted by Henrik

I don't follow you on your landscape images. Could you point to an example?

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Here begins a journey ... :)

Imagine a lake that you're about to photograph - if you float over the lake in a hot-air balloon and take the shot then one end of the lake will be at the bottom of the frame and the shoreline will rise up the photo until you get to the far end of the lake at the top - agreed?

OK - scene II - you land the balloon - pop on your wetsuit - and get into the water with your waterproof camera. You 1/2 submerge the lens and take a 2nd shot. In this scenario the far end of the lake WON'T rise in the shot - it'll be in the same plane as the front of the lake where you're shooting - agreed?

OK - scene III - no balloons, no wetsuit - you take the shot holding the camera about 5 feet above the ground. In this situation you effectively have something that's between the two extremes above (although obviously much closer to the "wetsuit" example than to the "balloon" example) - but - the lake line WILL still rise slightly in the frame. Normally this isn't a problem - but - where that "rising" coastline takes on the appearance of a horizon you can end up with a "visual conflict"; if you rotate the shot so that the waterline (rising coastline) is level then you might have other structures on a lean - but if you get other structures looking vertical then you will have the "horizon" on a slope.

It seems to be most obvious on shots where the natural (and correct horizon) is obscured by the likes on hills or mountain ranges (of unequal height). Not a biggie, but something that you sometimes have to take into account when leveling photos.

Does this help?

I think it's a projection issue.

How's this one look?
http://backup.cambridgeincolour.com/...Distortion.jpg

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Originally Posted by KentDub

I think it's a projection issue.

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This is probably the case - somehow. Thanks for trying to correct the photo - making the container a bit wider. Yet, in my eyes it still tilts - mostly. ;)

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Originally Posted by Colin Southern

Does this help?

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Alas, not a great deal. Maybe I'm stuck in thinking of the curve of the earth that shows, when you have a large horizon. I understand this is not what you're pointing at.

Maybe you have a photo showing what you mean? :)

Regards