"Throw" effects

Also known as a "gobo" or "cookie" (short for "cukaloris")
A very common effect in studio lighting is to put a patterned "flag" in front of the light source. It can be used to suggest off-screen elements that may not really exist, or to create more interesting patterns on otherwise dull or monotone walls.

Create a gobo effect by connecting a texture to the light's color (spotlights work best but you can texture a point light as well).

Color textures work also - great for stained-glass window light or other effects.

Light Fog

Add fog to a spot light. If the light casts depthmap shadows it will render the shadow patterns in the beam of light. You can adjust how defined the cone's edge of the fog is as well as the intensity and color. (You could even texture map a 3D texture to the fog).

If the fog shadows become grainy with higher intensity, adjust the Fog Samples setting.

You can also add global fog to a scene for depth-fading effects. Global fog does not cast shadows the way Light Fog does.

Lens Flare

This is a subset of Light Glow - available once the Optical FX node is added. Again, there are many attributes that allow for tweaking the lens flare pattern. Numerous flare patterns are indicative of a zoom lens (multiple glass elements in the lens).

Adjusting the Flare vertical and/or horizontal settings can get the angle across the screen fine-tuned.

If you really really must have a lens flare, a good idea is to render it in a separate pass and then composite it over the scene in post. That way you can make it more subtle if needed, or drop it out altogether if you decide it looks too cheesy.

Incandescence and Glow

An object can have the illusion of being a light source. This is a lighting effect that may not involve any lights!

In this example, the "glow stick" model has a shader with bright green in the incandescent attribute of the shader.  In addition, there is a "special effects" attribute for shaders where you can add a level of "glow intensity" that is creating the halo effect around the model.

Lastly, a green volume light (set as a cylinder) is casting the green light on the surrounding models.

Incandescence and Glow

Here, white incandescence is added to the shader for the light fixture, and glow intensity is added. A point light casting depthmap shadows is placed a short distance below each light "source".

NOTE: For all "glow" effects, a good idea is to render your glowing objects in a separate render pass for animations. Perhaps not using the Maya glow effect at all, but rather to use blur and add effects in your compositing software. This can allow for much greater control over glows and diffusion effects in your final result.

Incandescence and Glow

Another example of this technique. Here, a fluorescent panel effect is achieved with incandescence and glow on the shader. A few point lights are placed a short distance beneath each panel. Low resolution depthmap shadows are rendered with a filter factor of 3.

Incandescence in Shader Ramps

This is yet another variation on the use of incandescence in a shader. This time a ramp is mapped to the shader's incandescence attribute. Since the model is a NURBS surface, the texture conforms to the UV space of the model. The ramp gives the illusion of soft glowing light in a gradient across the surface.

This is a good trick for these kind of real-world "effects lighting", because it doesn't illuminate any neighboring objects.

Negative Lights

There are no shadow-casting lights in this scene.

There is a key light to the right, and a fill light on the left.

Inside the sphere is a point light with its intensity set to -1.

Negative lights can be used for fine-tuning an area as part of a larger lighting setup.

Shadow-Only Lights

In this image, the shadow is in the wrong direction from the light source. The key light is not casting any shadow, and the shadow is coming from a source that is not emitting any light.

To create a shadow-only light in Maya, create one light and adjust it to cast the shadow. Duplicate the light, keeping it in the exact same position. For the duplicate, turn off shadow-casting and set the intensity to the negative value of the original (e.g., -1.00).

Ambient Occlusion simulations

A common trick to create the global illumination effect of self-shadowing surfaces. One way to achieve this in Maya without the high overhead of true global illumination calculations is to create a "dome" of directional or spot lights with soft depthmap shadows. A range between 30-60 lights can be used for good effect.

If this is all that is used, the end result is like "sky light on a cloudy day". Instead, use it as a base for ambient lighting and add a key with specular highlight and stronger shadow-casting.

In some rendering systems, such as Renderman, ambient occlusion is done in a separate render pass and composited into the final image.