Vignette is a gradual darkening/lightening of an image towards its edges that highlights the subject of a photo by shading its surroundings. The effect creates visual interest and adds vintage elegance to your images. The effect parameters are adjusted in the Settings Panel.
Frame Parameters:
Frame Color. Using the color plate, adjust the color of the vignette. Click the color plate to select a new color from the standard dialog.
Transparent. Enable the check-box to make the vignette transparent.
Size (1-100). The parameter changes the effect area.
Opacity (1-100). The parameter defines the transparency of the vignette. At 100%, the vignette is completely opaque.
Shape (-100...100). The parameter affects rounding of the edges and changes the central part of the image from a rectangle (at negatives values) to a circle (at positive values).
Smooth Transition (0-100). The parameter adjusts the smoothness of the border between the vignette and the central part. Increasing the value increases the fading effect.
Position. Move the white marker to shift the vignette. You can see the current coordinates of the center in the X and Y fields.