Q: In the Light Fixture Project Schedule and Insert Light Fixture dialog boxes, what do Tilt, Arm Length, and Elevation/Mounting Height actually do?

A: The Tilt value controls the angle the light fixture is facing relative to the ground, as shown in the image below. A value of zero means the IES file is being used in its default state—typically, directly facing the ground.

As the Tilt increases, the light fixture will tilt in the direction the block is facing. For example, if the block is pointing right, the light fixture will tilt to face right; if it is pointing left, the light fixture will tilt to face left.

The Arm Length value controls the distance from the light fixture to its origin (typically the insertion point of the block), as shown in the image below.

As the Arm Length increases, the light fixture will extend in the direction the block is facing. For example, if the block is pointing right, the light fixture will extend to the right; if it is pointing left, the light fixture will extend to the left.

AThe Elevation/Mounting Height value controls the distance from the light fixture to the ground, as shown in the image below.