Using IES Files in revit Architecture 2009

Thanks to Yogesh Ishwar for this one.

To specify an IES file for a light source
Obtain the desired IES file.

You can obtain an IES file directly from the manufacturer, or use an IES file provided by Revit Architecture. The Revit IES files reside in the following location, by default:
C:\Program Files\\Data\Electrical Components\IES

Specify Photometric Web light distribution, as follows:
Open the lighting fixture family in the Family Editor.
In the drawing area, select the light source.
On the Options Bar, click Light Source Definition.
For Emit from Shape, select the desired shape.
For Light distribution, select (Photometric Web).
Click OK.
Save changes to the lighting fixture family.

Specify the IES file to use, as follows:
If you want the IES file to define light distribution for the entire lighting fixture family, keep the lighting fixture family open in the Family Editor. Click Family Types. For Name, select the family type to modify.
If you want the IES file to define light distribution for selected instances of the lighting fixture family, open a project that uses it, and select a lighting fixture in the project. Right click, and click Element Properties. Click Edit/New. Click Duplicate, specify a name for the new family type, and click OK.

In the list of type parameters, scroll down to Photometric.
For Photometric Web File, click in the Value column.
Click (Browse).
Note: The Browse button displays after you click in the field.
Navigate to the desired IES file, select it, and click Open.
Click OK.

Save changes to the project or the lighting fixture family.
In the drawing area, the shape of the light source reflects the specified IES file. To see the light source in a project view, you must make light sources visible.