I figured out how to do it –
Edit file shortcodes-ultimate/inc/core/shortcodes.php
Find ” // Slide content with link “
Replace the line below that comment line with the following:
if ( $slide['link'] ) $return .= '<a href="' . $slide['link'] . '"' . $target . ' rel="lightbox" ><img src="' . $image['url'] . '" alt="' . esc_attr( $slide['title'] ) . '" />' . $title . '</a>';
.
For it to work, you need to have any lightbox plugin installed, I used “responsive lightbox”, and make sure that the rel is “lightbox” in the settings.
This will open any photo with rel=”lightbox” in a lightbox!!