I was studying shaders trying to get a grasp on how to use them effectively. In the Palm scene the palm tree uses  overlay in the color channel (using carrara pro 5). The other plant in the scene" Pink Laurier" uses a mixer in the color channel. Can someone explain why they are different , and does it even matter. Why would one choose one way and not another?

 Hi wscottaart,

To get a clearer understanding of what is going on, uncheck the "Filter Simple Shaders from tree". This will show exactly what is going on between the two channels that are being combined in the color branch of the shader tree. The difference is one of personal taste. All of the mixing options are found under the "Operators" option in the shader pull-down type. 

Just as in Photoshop, the Overlay, Add, Subtract, etc. give your different ways to combine what you have going on with the two layers/branches that are within the mixer option.

Mark