Why do horizons have to be straight?! (NTP Query)

[Mathy]

What an interesting question Having thought about it, I would assume that any photo which includes a horizon, is by nature going to look 'odd' with a crooked horizon because our eyes and brain require it to be level. After all, horizons that are out of whack do cause travel/sea sickness. All of our biology that works together to spatially locate us in the world operates from the perspective of vision (for sighted people). Try standing on one leg with your eyes open, and then try it with your eyes closed, it becomes quite difficult.

So from examples above, William's photos don't have an horizon, so they're not disturbing. MattNQ's first photo isn't visually disturbing because the statue has maintained a right angle to the horizon, so it looks ok, might get a comment, but essentially, the angles between things are all right. The second photo however, is truly sneaky, there is a deliberate horizon included but it's been shot from a perspective that makes it an unusual and very fine photo Oustar79's pic is using a trick of perspective, which I don't find particularly disturbing, but interesting.

Now Fotog's pics from a rolling ship would be very interesting to see, as I imagine they could be quite disturbing, depending upon where they are taken from, if there's no vertical element, then our eyes/brain can't cope.

IMHO an horizon is the natural horizon, the one that gives us sense of balance/context. Our brains/eyes understand right angles (or the relationship between horizontal and vertical). If you mess with that relationship (such as MattNQ did in photo #2), then the photo can be disturbing. If you shoot a landscape with a tilted horizon, then the natural response is going to be "straighten it".

Thank you for your most interesting question, cheers Deb

[ricktas]

I hate it when a photo has conflicting levels. I had one recently where if I levelled the photo based on getting the vertical parts vertical, the background looked disconcertingly tilted, but if I straightened the horizon, the verticals looked all wrong, and no amount of lens distortion correction would fix it, in the end I discarded the photo in frustration and put it down to it being an error in my composition of the shot. The mountain range wasn't level, but with no other ground reference, the brain tried to make that the horizon, so the mind complained if it wasn't level, but that tilted all the buildings vertical lines, and the brain complained about that too.
I think you answer your own question with the reference to the quote about making anything skewed look very deliberate. A couple of degrees people will put down to badly taking the shot and want it straight, whereas if you deliberately took a shot of someone at 45 degrees, you'd be making it pretty clear it was for artistic or emphasis reasons, and that would be much less likely to trouble the viewer, but it may still not be as aesthetic to people as a level composition of the same subject.

Download a trial of DXO optics : http://www.dxo.com/en/photo/dxo_optics_pro
It is specifically just for correcting lens distortions, and does quite a good job of it.

[arthurking83]

As has already been said, while they generally tend to look better when leveled, horizons can be made slanted and the the image still appear to be pleasant.

And there's always the situation where your 'horizon' is tilted and you may not even know it too.

Bottom line is; if it looks appropriate or somehow interesting then leave it tilted, otherwise make it straight.

[Ezookiel]

Thanks Rick, I'll have a look at it for other shots. But on this shot it wasn't lens distortion, it was a sloped mountain top that was visible behind the building.
Because I had cut the bottom of the mountain off in the photo, it didn't look like mountain, it looked like horizon, and so the brain wanted it to be level. But if I made it level, then it tilted the verticals on the building and the brain wanted those vertical. Because it was only a few degrees, it seemed to make it worse than if it had been quite a bit sloped, which might have shown it clearly to be mountain not horizon.
It was a learning experience. I should have composed better so there was some actual horizon visible, which would have solved the problem.