15 October 2017

Why is this image distorted?

This is the greenside area of the third hole at Tianna Country Club in Walker, Minnesota.  The ripples from my failed approach shot have faded away.  What interests me is the birch trees and their reflection in the pond.  In real life they were perfectly upright.

I photographed the scene with my iPhone SE, which has a fairly wide-angle built-in lens (29mm I think), but I don't remember encountering this much distortion using wide-angle lenses on my old film and digital cameras.

I've encountered obvious distortion with this phone taking panorama images, but this was a conventional one.  I need some education on the "why" and any coping techniques, and I figure asking the readership here will be faster than searching the 'net.  Thanks in advance.


  1. What you are seeing is the result of "barrel lens distortion" due to the wide-angle 'fish-eye' type lens in most smartphones. See here:


    There are apps such as skwrt that can correct this effect.


    1. Not an expert (though optics enthusiast), but judging by the angle of the trees, wouldn't this rather qualify as pincushion distortion instead of barrel?

      That is, if this is lens distortion at all. Thing is, wouldn't that result in the trees being curved rather than perfectly straight as they appear to be (just at an angle)? Might the SE have some built-in feature that attempts (imperfectly) to counteract lens distortion?

      Thanks for the app link btw! Imma use that, yo.

    2. I'm skeptical the effect is systematic optical distortion. This would tend to make the trees curved not just tilted and it should also be progressively increasing towards the corners, not a constant tilt effect. More likely the trees are not straight as claimed.

      It may well be the trick is in the mind. We are so inclined (pun alert) to use trees as a reference point for vertical that our brains will tend to correct their appearance to us towards the vertical as an absolute reference. It's one reason you get sea sick inside a ship. Your brain's vertical references from sight are overriding the ears. Generally sight is better when it works.

  2. Are you sure the trees were upright, Stan? I found this picture on the web (which appears to have the same rock in it as yours), and those trees do look like the grow at a bit of an angle.

    1. Also (sorry for taking this way too serious, lol), if this were lens distortion, wouldn't the green fence post on the right lean at pretty much exactly the same angle as the surrounding trees?

    2. Drab, I'm relying on my memory now, and it's possible that there was a tilt to the trees that I didn't see. That green was carved out of the woods just a couple years ago to extend the length of the hole, and some mature birches may have "leaned" toward the sunlight. It wasn't apparent to me at the time, but maybe I had too many tears in my eyes from losing my favorite ball in the pond...

    3. Oh dear, I'm sorry for your loss :) Well, you're not to blame for your brain doing a little selective memorying - it does that all the time to prevent you from going crazy, but sometimes it can be astounding how it leads to "seeing" things completely differently from what was really there. (Plus, lens distortion may still be part of the story.)

  3. This is just the trees leaning.
    Pincushion or barrel distortion both mostly affects the edges of the picture.
    If you look at the very middle of the picture, the trees in the reflection still leans.
    The surface of the water is horizontal and you can see the trees both in the reflection and above are leaning the same direction.


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