What is distortion?

Distortion in photography Is the optical effect in which the lines in the photograph are bent

Distortion

Distortion

Distortion is mainly of two types - barrel-shaped (convex, Barrel distortion) and pillow-shaped (concave, pincushion distortion). Distortion is usually called simply. 'barrel'and'pillow'. But it can also be difficult or complex distortion (complex distortion), in which distortions in different areas of the image have a different type and intensity. Complex distortion is rather difficult to correct with the help of graphic editors, since there the distortion can go in 'waves'. Professional photographers affectionately refer to complex distortion as' camel ', sometimes'two-humped camel', since such distortion often gives peculiar visual humps and depressions in the image. In foreign literature, you can find other interesting names for distortion.

Different types of distortion

Different types of distortion

Class Lenses'Fish eye'(Fish Eye) have a very strong barrel distortion, the use of these lenses allows you to create unusual photographs, in which distortion often plays a key role in creating the desired visual effect. Usually no one corrects distortion from Fish Eye lenses. Below is an example of a shot on the lens Zenithar 16mm F2.8 MC Fisheye.

Sample photo from the Zenithar 16mm F2.8 MC Fisheye lens

Sample photo from a Zenitar 16mm F2.8 MC Fisheye lens. Curved straight lines of houses are visible.

The fisheye lens is a wide-angle lens, therefore it is often used in rooms with limited space.

Photos of people on a fisheye

Photos of people on a fish eye. Shooting a chess tournament.

Because the distortion is mainly inherent in wide-angle lenses, and wide-angle lenses themselves in a special way convey the perspective of the image, then the distortion effect and a special transfer of perspective can give photos an unusual look:

Super wide angle shot

Super wide angle shot

It is especially difficult to shoot people on ultra wide-angle lenses:

Super wide-angle shooting without distortion correction

Super wide-angle shooting without distortion correction

If you do not have a specialized Fisheye lens or a super-wide-angle lens, then the effect of strong distortion can easily be simulated by almost any processing program. Below, I specifically enhanced barrel distortion to create a visual effect.

Specially enhanced distortion to create volume effect

Specially enhanced distortion to create volume effect

Usually distortion is easily corrected using software, almost all editors have the ability to compensate for the distortion effect of the lens, just find Distortion slider and twist it back and forth. However, when compensating for barrel distortion, you usually have to crop a part of the frame, since empty space enters the image field. Many cameras have automatic distortion correction functionAt the same time, the camera, taking into account the lens parameters, can calibrate the original image as efficiently as possible.

Adjust distortion in Lightroom

Correction of distortion in Lightroom. Strengthening Pillow Distortion. Enhanced barrel distortion. Original.

Pincushion distortion is usually a problem for telephoto lenses, but the distortion level is low enough to visually notice a flaw in the image. Due to the presence of pincushion distortion in body lenses, lenses are said to 'flatten' the image as pincushion distortion visually reduces volume.

Personal experience

In most shots, it is quite difficult to notice distortion, but there are times when distortion interferes very much. When correcting distortion in a RAW converter, it is not always possible to achieve the desired result. In general, modern standard lenses have well-corrected distortion. Distortion hard to notice if there are no straight lines in the photo.

Conclusions:

Optical distortion is curvature straight lines in the photographs. Distortion creates interesting visual effects that can harm photos, but can also help create an unusual picture. Correcting a slight distortion using software is not difficult.

Help to the project. Thanks for attention. Arkady Shapoval.

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Comments: 11, on the topic: What is distortion

  • Georgia

    I would also add to the article “examples of photos of how the portrait / plot changes depending on the focal one with the removal of the same frame (like there were such examples on the network) - it would be quite useful, you could immediately throw a link to the article at people, without looking every time. And then every time to explain to people “on their fingers” why all such thick or scary ones turn out to be so thick or scary on a “soap dish / cell phone” is tiresome. ((

  • Georgia

    yeah. Bo the main, ever-asked question is the question: “I’m trying to shoot the bottom half a meter from my face so I liked myself, and with a dog in my arms, and on my camera phone / cell phone / on a whale twisted up to 18 mm maximum” - still refers to portrait photography / teaching it, it is in it that distortion is a stumbling block, in other genres it is more like an “artistic device”.
    So, I’m just driving / studying right now, and at the same time I’m learning a couple of acquaintances, and everything is extremely convenient and accessible on your site, so yes, I’m a mercantile kyu and I want it to be even more convenient and complete. ;))

    • Arkady Shapoval

      There will be time - we will do it.

  • Vladislav

    Hello, in lightroom 3 I can’t determine my lens for correction of dystoria and you can’t select it manually because it is not there, although once before when I stuck a flash drive, it automatically detected my lens and easily corrected the dystoria, the nikon 35mm1.8G lens can tell me what is wrong with him, light room reinstalled set 4 version the same

  • Sergei

    Yes, a good article, I too when I leave, and then zoom in, sometimes I wonder why this is.

  • harryk

    Here, however ... I worked a lot (including a little professionally) on TVs / monitors on CRTs, and of course I knew and regulated the expressions “geometric distortions of a raster like a barrel / pillow”, but the term “distortion” somehow passed by: - (Let's study - now optics ;-)

  • Alexander

    The program with a demonstration of distortion correction in the photo is called PerspectivePilot-3.5.0-portab. Free No need to load bulky photoshop. Not buggy. Link: http://s160.turbobit.net:9010/download.php?name=PerspectivePilot-3.5.0-portab.rar

  • Sergei

    Arkady, hello!
    will you tell me:
    1. What would be better: for the camera to automatically remove distortion ?! but, I suspect there are 3 problems: it will not remove ideally, tk. they do not have such a function, but only conditional (moderate-medium-maximum); time will be wasted on intra-camera processing - and this is not the best way out with frequent continuous shooting; third-party lenses (Tokina, as an example) - not supported by the camera (we are talking about Nikon D7000, D600).
    2. How exactly do you use camera corrections? :-)

    PS: thanks for the interesting and useful photo blog! ;-)

    • BB

      Are you very annoyed by the distortion of your optics?
      Try different modes of intra-chamber correction, shoot buildings / structures with different settings. Decide if you need it. Write your impressions in the comments, maybe others will come in handy.

      • Sergei

        not much, but annoying (perhaps only by the type: the effect of the reverse placebo)! :-) That is why I selected optics for the crop with the least distortion: Nikon 35 2.0D, Nikon 50 1.4Zh and D, Nikon 85 1.8D ... and after purchasing FF Nikon D600, I looked at http://photozone.de/, and there are already more distortions ...
        thanks for the advice! ;-)

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