In the hypershade:
1.Change to the 'create materials' menu (top of sidebar to the left)
2.Click on 'surface shader' to create a new 'surafce shader' material.
3.Change to 'create textures' menu
4.Click on 'ramp' to create the ramp texture
5.Middle mouse click on the ramp and
6.Release over the surface shader,
7.Select other from the menu that appears and
8.Select 'outcolor' in the outputs column and
9.'outcolor' in the inputs column and
10.Then click close.
11.Change to 'create utlities' menu.
12.Click on surf.luminance to create the surfae luminace utility.
13.Middle mouse click on the surf.luminance and
14.release over the ramp.
15.Select 'other' from the menu that appears and
16.Select 'Out Value' in the outputs column and
17+18.Select 'V cord' in the inputs