Distortion is an error or an error in the aggregate of optical elements, during which the linear increase coefficient varies along the field of view of the lens.
Definition of distortion
Distortion from the Latin language translates as "curvature." When distortion occurs, the similarity between the object and its visual image is violated. Distortion is an error. It can be fixed at the stage of selecting the optical system when choosing lenses or when editing photos in a PC. Distortion is a noticeable phenomenon if there are straight horizontal or vertical lines in the frame. With distortion, straight lines become curved outward or inward. It is pronounced when shooting architectural buildings, trees, pillars and other objects.
Types of Distortion
Distortion occurs in two forms - it is barrel-shaped and pillow-shaped.
Barrel-shaped or convex distortion is distinguished by the fact that the bend of the line is directed outward, while the object becomes convex, and this is very noticeable relative to the edges of the image.
As for the pincushion or concave distortion, it is distinguished by the bending of the line closer to the center of the frame, that is, the lines appear to be concave into the image.
Also, barrel-shaped distortion is called positive, and pillow-shaped distortion is called negative.
Shooting Distortion
The cause of camera distortion may lie in the lens of your camera. If it is more clear to disclose this, it can be noted that when using cheap lenses, the quality of which you can doubt, the image is distorted. This most often refers to lenses called the “Zoom Lens”, they have a variable focal length, which is why distortion occurs.
The second reason lies in the moment of photographing - the convergence of lines that are parallel to each other in an inclined position, or when the photographer himself is leaning. This mainly happens when tall buildings are removed from a lower angle.
To avoid distortion when shooting, you can use a few simple rules:
- to get a high-quality lens, preferably wide-angle;
- move away from the object, and when photographing bring it closer.
If these two simple rules didn’t help, then photo editors can solve this problem. This is pretty easy.
Processing distortion correction
If the distortion is not noticeable, then it can be removed by downloading the Adobe Camera Raw tools using the Adobe Lens Profile Downloader. Open the Adobe Camera Raw program, click on the snapshot that you want to edit. Go to the Lens Corrections tab and activate the lens profile by checking the Enable Lens Profile Corrections checkbox.
First you need to open a photo in this program and go to the Lens Corrections section, then select Manual, there you will see such positions as distortion, vertical, rotate and others. You need to move the distortion slider to minus as much as it is required to completely eliminate distortion.
“But how to fix the distortion in Photoshop?” You ask. Yes, easy! First, open the image in Adobe Photoshop, then the Filters tab and select the Lens Correctons. You will see a window and you should open the Custom tab, then move the slider to the characteristics called Remove Distortion to a positive value until the distortion is fully corrected.
Intentional distortion
Photographers do not always consider distortion a lack of photography, some try to do it intentionally with the lens or when processing photos in the editor.
As for the lens, it is very common Fisheye or as it is also called "Fishy". This is a type of so-called ultra-wide-angle lenses, which have a convex front lens at 180 degrees, which is why distortion is obtained in the pictures. The fisheye lens can be of two types: circular and diagonal. A circular lens is most commonly found in meteorology to take photos of the sky. The diagonal lens is the most common among photographers. We even know the name of the first photographer who first used this type. This is Lev Abramovich Borodulin, who is a famous Soviet and Israeli photographer specializing in sports photography.
There are a number of other lenses, but they are all aimed at creating image distortion, such devices can be found in Nikon, and Canon, and other companies involved in the production of cameras.
You can make distortion in "Photoshop" on purpose, for this you need to open the desired image, select it and go to the "Editing" tab, then you need to select the "Transformation" function, a number of additional functions will appear there, you should select "Warp". Your image will be placed in the grid, and it is in it that you need to work. Drag the image exactly as you need it.
Conclusion
Despite the fact that distortion is most often perceived in a negative way, in some cases this effect is used intentionally to focus on a specific moment or part of an object. This effect has been used in the photo industry for a long time, but has gained great popularity relatively recently.
Distortion is a way of self-expression of a photographer, an opportunity to show their individuality. It gives the picture a special chic and specificity. Today, an increasing number of photographers around the world are beginning to work closely with this effect and make full use of the opportunities that distortion provides. Of course, not all professionals, and even ordinary people, like photographs taken using this effect, but there is no point in denying the fact that in recent years interest in distortion has greatly increased.