How can you set up partial transparency on an object?
For example if you are working with an image plane and would like it to be 50% transparent? The Object's transparency option has an on/off option, is there a way to make it a certain percent?
In Cycles the most basic way would be to use a mix shader to mix transparent and diffuse. The Mix factor determines the amount of transparency.
If you use an image that has an alpha channel, then you can use the alpha as factor to mix transparent and diffuse.
Add a material to the plane, check Transparency, click Z Transparency, and set object to 0.5.