Production of barrel springs and their assembly into finished barrels

The fisheye lens deliberately keeps the barrel distortion of the image.

At the 50mm focal length, barrel distortion is slightly noticeable.

Barrel distortion correction leaves black empty space in image periphery.

Distortion: The deformation of the image in either barrel or pincushion form, particularly perceptible with shots taken at short focal lengths;

Distortion: The deformation of the image in either barrel or pincushion form, particularly perceptible with shots taken at short focal lengths;

In barrel distortion, image magnification decreases with distance from the optical axis.

In "barrel distortion", image magnification decreases with distance from the optical axis.

In “barrel distortion”, image magnification decreases with distance from the optical axis.

It nearly illuminates 6x6 at infinity, but suffers severe barrel distortion.

And optically, they are terrible, with lots of barrel distortion and other issues.

You can select barrel and pincushion distortion and specify "strong," "medium," or "weak" for each.

The photographer can select barrel and pincushion distortion and specify “strong,” “medium,” or “weak” for each.

Image before correction, showing marked barrel distortion on the horizon line, and strong vignetting (darkening in the corners).

Image before correction, showing marked barrel distortion on the horizon line, and strong vignetting (darkening in the corners).