Compensating for lens vignetting

Vignetting is common lens defect where the edges, especially the corners, of an image are darker than the center.

To compensate for lens vignetting:

1. Make sure the Camera Raw dialog box is in Advanced mode.
2. In the Lens tab, move the Vignetting Amount slider to the right (positive values) to lighten the corners of the image or move the slider to the left (negative values) to darken the corners of the image. You can also enter values in the Vignetting Amount text box.
3. Move the Vignetting Midpoint slider to the left (lower value) to apply the Vignetting Amount adjustment to a larger area away from the corners, or move the slider to the right (higher value) to restrict the Vignetting Amount adjustment closer to the corners. You can also enter a value in the Vignetting Midpoint text box.