Create a light with Spotlight distribution. > Spotlight Parameters rollout
The Spotlight Parameters rollout appears when you select a Target Spot or Free Spot, or a photometric light with spotlight distribution.
To see the spotlight cone in viewports:
The cone is always visible while the light is selected. This setting keeps the cone visible when the light is unselected.
In the Spotlight Parameters rollout > Light Cone group, turn on Show Cone.
Select another object, deselecting the light.
A wireframe outline of the light's cone appears. The hotspot region is outlined in light blue, and the falloff region is outlined in dark gray.
Note: The cone is always visible while the light is selected.
Tip: The hotspot and falloff borders are not visible in shaded viewports. Use controls in the Light Cone group to adjust hotspot and falloff in the viewport. Render the scene to see the full effect of the light's border.
When the hotspot and falloff values are close in value, the light casts a hard-edged beam.
To set the shape of the light beam:
Choose either Rectangle or Circle.
The shape of the light's cone changes to reflect the shape you chose.
If you chose Circle, you are done. If you chose Rectangle, you can now adjust the aspect ratio of the rectangular light in the Aspect field.

These parameters control hotspots and falloff for spotlights.
Show Cone—Turns display of the cone on or off.
Note: The cone is always visible when a light is selected, so turning off this check box has no apparent effect until you deselect the light.
Overshoot—When Overshoot is set, the light casts light in all directions. However, projections and shadows occur only within its falloff cone.
Hotspot/Beam—Adjusts the angle of a light's cone. The Hotspot value is measured in degrees. Default=43.0.
For photometric lights, the Beam angle is the angle at which the light's intensity has fallen to 50 per cent of its full intensity. (As opposed to the Hotspot, where intensity is still 100 per cent.)
Falloff/Field—Adjusts the angle of a light's falloff. The Falloff value is measured in degrees. Default=45.0.
For photometric lights, the Field angle is comparable to the Falloff angle. It is the angle at which the light's intensity has fallen to zero.
You can also adjust hotspot and falloff angles in a Light viewport (looking at the scene from the point of view of the spotlight).
Circle/Rectangle—Determine the shape of the falloff and hotspot areas. Set Circle when you want a standard, circular light. Set Rectangle when you want a rectangular beam of light, such as light cast through a window or doorway.
Aspect—Sets the aspect ratio for the rectangular light beam. The Bitmap Fit button lets you make the aspect ratio match a specified bitmap. Default=1.0.
Bitmap Fit—If the light's projection aspect is rectangular, sets the aspect ratio to match a particular bitmap. This is useful when you are using the light as a projector light.