20 THINGS I KNOW ABOUT AFTER EFFECTS LIGHTS …

            

1-Which type of light would be best to replicate a bare light bulb?

            Point.

2- How do lights affect 2D and 3D objects differently?

            2D layers ignore lights where 3D layers are affected by them.

3- What is Ambient Light?

            Light that does not have an identifiable source.

4- How is an Ambient Light different from a Source Light?

            Source light has a clear and identifiable source and direction, which can be positioned within            the composition. Ambient light doesn’t consider a specific source and illuminates compositions evenly.

5- What is a Parallel Light, and why would one use it?

            It is a variation of point light that lacks a cone structure.

6- Describes what happens to the illumination of an object as it moves away from a light.

            The further you move the object away from the light source; the illumination of the object itself begins to decrease.

7- What happens to a layer as it rotates away from the light source.

            The illumination of the object decreases.

8- Describe a light's Cone Angle?

            We use the cone angle for a light to control how spread out we want our light rays to be. The wider the angle is, the more area is illuminated. The smaller it is, the more focused on one area we become.

                  

9- How do I move the light without moving the POI?

            You manipulate the light’s actual position and location.

10- How do I move BOTH the light AND POI at the same time?

            By manipulating the position of the light within the comp layer.

11- Which type of light is the ultimate 'FILL' light?

            Ambient Light.

12- What does the term 'Diffuse' mean?

            It is the scattering of light. It will generally soften an object, reducing sharpness an reflection.

13- What does the term 'Specular' mean?

            The area of reflection of light that is the strongest highlight on an object.

14- Can a precomp layer cast shadows?

            Yes

15- What are the 5 requirements that must be met for shadows to work?

            1) A non-ambient light must be directed at both the layer you want to cast a shadow and a layer to receive the shadow.

            2) Cast shadows option enabled.

            3) The layer casting a shadow must have cast shadows on.

            4) The layer receiving a shadow must have accepts shadows on.

            5) There must be space between both layers in z-axis.

16- As objects get closer to the layer receiving it's shadow, does the shadow get sharper or more diffused?

            The closer an object is, the sharper it becomes.

17- If a layer's  'Light Transmission' is set for 100%, how does that affect the layer?

            It mixes with the layer’s colors. The back of the layer are also illuminated and become transparent.

18- A 'GOBO' is like a stencil placed in front of a light.  Does the layer have to have an alpha, or can             the luminosity of the image work?

            It must have an alpha.

19- Adding lights really slows down the render of a scene, what are 3 things that you can do to speed up visual feedback?

            1) You can turn off lights that you don’t need as you work.

            2) Turn off realtime updating by pressing Option (alt) as you scrub.

            3) Enable Draft 3D.

20- Can I adjust the brightness intensity of a light below the value of 0?  What happens if I do?

            Yes, it removes illumination.