Adobe Illustrator comes with a diverse set of filters and effects to enhance and create artwork. The list of filters and effects have many matching counterparts in each of the menus, but their functions and purpose are what set them apart.
Same Functions, Different Purposes
When the Filter and Effect menus are viewed, a lot of similar choices are available. The results for using the same function in either menu will result in the same results on the screen, but there’s a different purpose for each menu’s listings.
The difference can be easily explained with an example. Add round corners to a pair of rectangles by choosing Stylizes… > Round Corners from each menu. Use the same radius value for each rectangle. Then choose View > Outlines to see only the paths of the objects. Notice that the Filtered rectangle’s paths have rounded corners, while the Effected rectangle’s paths are still squared corners. This is the key to understanding the difference: Filters change the paths of an Illustrator object, Effects give the appearance of change to an Illustrator object without changing the paths. See below for a diagram of this example.
Filters are permanent changes to an object’s shape or style. Effects give the appearance of new styles and shapes without changing the original objects’ shape.
Editability and Flexibility with Effects
Using the example of the round cornered rectangles, the Effected object can be edited so that the corner radius can be changed or removed. With the object selected, choose the Appearance palette (Window > Appearance) and note that the listing of object attributes contains “Rounded Corners” with an “fx”. Double-click on this entry, and the Round Corners dialog box appears, giving the opportunity to change the corners.
Clicking on the Filtered object will list only the stroke and fill characteristics of the object in the Appearance pallette. The rounded corner values cannot be edited on a Filtered object since the filter was applied to make the object permanently round cornered (The Undo command is the only way to change the corners back to square).
Multiple effects can be applied to an object in the Effect menu and they will appear as individual listings in the Appearance menu. Add a drop shadow, give it a warped arc shape, and each of those effects will appear listed. Specific effects can be removed without changing the other effects. This allows experimentation with effects and gives incredible flexibility to the creative process.
Filtered items retain their true appearances in their shape and do not allow for experimenting. Once a document is saved and reopened again, filtered objects are permanent in their state at the opening. Effected objects can be edited over and over and are not limited to a document’s session of being open.
Using Photoshop Filters and Effects
There are many Photoshop styles available in these menus, but the difference here is that these styles in the Photoshop Filter menu are used on embedded and rasterized objects, while Effects menu styles can be applied to vector items. These Photoshop Effects will be rasterized when outputted, but give the same flexibility in editing as Illustrator Effects.