Particle Group > Glow Group
The Glow group adds -- you guessed it -- a glow to the particles. Active when Glow Sphere or Star are chosen as the Particle Type.
At left, the full Glow group. At right, the Glow Sphere and Star options in Particle Type.
Size
Sets the size of the glow. High values give a heavier glow to the particle. Lower values give a faint glow.
Left to right, Size is set low and high.
Opacity
Sets the opacity of the glow. High values give a more solid glow to the particle. Lower values give a more transparent glow.
Left to right, Opacity is set low and high.
Feather
Sets the softness of the glow. High values give a feathery soft edge to the particle. Lower values give a more globular, solid edge.
Left to right, Feather is set low and high. Transfer Mode
The Transfer Mode controls how particles are composited together. There are three options: Normal, Add and Screen.
Normal: Normal composite operation.
Add: Particles are added together. Useful for light effects and fires.
Screen: Particles are screened together. Useful for light effects and fires.
Left to right, Transfer Mode is Normal, Add and Screen.