If necessary, use the Select Image tool
to
adjust the position of the non-vanishing point images. A non-vanishing
point image has a red border around it when selected.
When you apply perspective correction to a composition,
the non-vanishing point images are linked to the vanishing point
image. You can break this link by clicking the Reposition Only button,
by separating the images in the work area, or by dragging the vanishing
point image back to the lightbox. After the link is broken, images
return to their original shapes.
The perspective correction
only works up to an approximately 120° angle of view. If your composition
has a wider angle of view, deselect the Perspective option.