What is lens distortion? In this article, I am going to explain it in simple language. Lens distortion is a deformation that occurs in the image after capturing from the camera lens. But, how to identify lens distortion in any image. If things look curvy in the image or straight lines appear bent then there is a distortion in that particular image.
There are two major types of distortion. 1. Optical distortion 2. Perspective distortion. Due to optical lenses, design image causes optical distortion. Perspective distortion is caused by the position of the subject in the images.
Optical Distortion
In optical distortion, there are three types of optical distortion.
- Barrel distortion
- Pincushion distortion
- Moustache distortion.
Barrel Distortion
In Barrel distortion, the straight lines are bend outside in the shape of a barrel this type of distortion is called barrel distortion. At the centre, the distortion amount is very less due to the lines being straight. But at the edge lines get curved outwards and this problem commonly occurs in wide-angle lenses. In wide-angle lenses, the field of view is wider as compared to the size of the image sensor. We can easily notice barrel distortion in the architectural images. If you are using wide-angle lenses or zoom lenses with short focal lengths then it will definitely generate barrel distortion.
Pincushion Distortion
Pincushion distortion is a distortion in which straight lines bend inward from the centre of the image. Pincushion distortion generates the opposite effect from barrel distortion. Mostly pincushion distortion is seen in telephoto lenses. These types of distortion are easily noticeable in the telephoto end of the lens. Pincushion distortion mostly affects objects with straight lines. If you want to reduce pincushion distortion from your objects then try to place your objects close to the centre of the frame. In pincushion distortion, we can see more distortion at the frame’s edge.
Mustache Distortion
Mustache distortion is a combination of barrel and pincushion distortion. This is one of the most complex forms of distortion. In mustache distortion, straight lines are back outwards at the corner. And in the centre of the frame straight lines are curved inwards. It’s very difficult to correct mustache distortion. Mustache distortion is also known as wavy or complex distortion. It is one of the most difficult forms of optical distortion to deal with it.