The left-hand browser area of the Lamp Settings dialog box is similar to those of other Library Part elements.
The right-hand Settings panels of the Lamp Tool dialog box controls are similar to those of Object Settings.
All lights and lamps have certain parameters in common, on the Light Settings Panel of Lamp Tool Settings.
The General Light Sources folder contains light sources that serve to illuminate the project, and have many sophisticated optional effects. The effects are advanced-level settings that are separated from the basic parameters in the Settings dialog box.
The effects you set for your lamps and light sources are taken into consideration for Photorenderings. As a rule, the global effects are set in PhotoRendering Settings (turn on GI, Lens effect, Intensity). You can then fine-tune these in your individual lamp/light objects.
Note that certain individual Lamp parameter settings will take effect only if the corresponding global parameter in PhotoRendering Settings is switched on. These situations are noted in the descriptions of light effects, which follow.