This is a simpel layer effect for creating light bloom. It blurs bright parts of an image to create the effect of the human eye looking into strong light.
For using with several image types here some general advices for tweeking the parameters:
-For images with one strong light source use a high radius, an average blackout and a high brightness value.
-For images with several light sources use average blackout, average brightness and low radius.
-For images with only few lights (or bright parts, reflections etc.) use average radius, low blackout and low radius
-For images with a lot of bright parts that are no lights (e.g. sky, white walls or sth. similar) use high blackout, average brightness and average radius