Image Gallery with Lightbox Effect
Images with Specific Class
There are options in the plugin to make it so that a lightbox is applied to every image with a specific class. We even go beyond this and have made it so that you can choose any CSS selector to apply a lightbox to (for example: #mainDiv .myClass:nth-of-type(2n+3) .myImageClass). The following three images all have the class .attachment-large.