This is one of over 4720 effects generated by Filter Forge, a Photoshop plugin that allows you to create your own filters.
To open this filter, you must have Filter Forge 1.0 or higher installed on your computer. If you don't have it installed yet, click here to download Filter Forge
A nice effect that reminds me of an eclipse. This filter makes a quarter moon shape over your image, and various other cool patterns.
polka dots circle moon eclipse