The proper use of filters can significantly extend Photoshop's capabilities. Filters can allow you to achieve what otherwise would be time-consuming results more quickly; they can even unlock options that could not be done with built-in tools. By definition, a filter must reside in Photoshop's Plug-Ins folder. Other features, such as Actions and Layer Styles, should not be confused with filters.
A few filters have no user interface (for example, Average, Despeckle, Facet). If a filter does not have ellipsis (...) after its name, it means there is no user interface. These filters are fairly limited and will likely fall off your favorites list.
Most filters, however, will have some form of a user interface. Some filters have their own window; others use the Filter Gallery. No matter which interface you use, consider checking the Preview box option. This allows you to see the filter's results to your canvas before applying it. Here are a few more tips about using a filter's interface:
Using the Filter Gallery
As of Photoshop CS, Adobe changed how several filters work. Forty-seven of the built-in filters now use the Filter Gallery interface. This larger window allows for the application of multiple filters in one pass, as well as to preview the effects before applying them.
Tip: Creative Filter Use
Many filters will produce pleasantly unexpected results when used in situations they weren't designed for.
Many users wonder why only some filters are in the gallery. Adobe placed most of the filters that were meant for artistic or experimental purposes (such as the Sketch filters) into the gallery. Effects that are more surgical (such as the Smart Sharpen filter) have their own windows. The primary benefit of the Filter Gallery is that you can see the results of combination effects. Let's explore the Filter Gallery interface: