Lesson 4: Diffusion, Direction, Using One Light Source (Continuous)

In this class, we examined the impact the direction of light has on the highlights and shadows in a photograph. We began by observing a single light source on a sphere, taking note of the way light falls onto its surface.

• A highlight side is created
• A shadow side is created
• A core is created in the transition of the highlight and the shadow
• A cast shadow is created
• A small amount of bounce fills the shadow side at the bottom of the object because it is on a white surface (at bottom left of object in this image)
• (Not shown: a specular highlight is created when we can see the reflection of the light source in our subject)

It’s important to remember that the positioning of the light changes the way the light falls on your subject. 

Next we observed how placement of a single light source can change the shadows and therefore dimension of a 3D object such as a cube. 

Goal 1: Make all three sides the same tone. To do this, we moved the light to sit right above the camera.

Goal 2:  Light the styrofoam cube so that each side had a different value: highlight, mid-tone, and shadow. To do this, we had to place the light to the right of the camera and slightly above the cube. 

In our first example the light is placed directly next to and slightly above the camera which creates a very even light and not much shadow. 

In the second example the light was placed above and to the right of the subject so that one face was in shadow, one face was a highlight and the third side was in the middle (about one stop difference between each side). A black piece of mat board was placed on the white surface below the cube, acting as flag that blocked any bounce/spill, thus further darkening the shadow side of the cube. 

Next we observed different types of diffusion material and how it can change the quality of light.

First we looked at different densities of Rosco Tough Spun:

Least Dense































Most Dense




Next we looked at other types of Rosco white diffusion filters

Least Dense














More Dense











Two filters overlapped








Light diffusion (such as ¼ Tough Spun) spreads some of the light, while the hotspot from the original source remains. Heavier diffusion (such as Tough Rolux) completely spreads the beam out.


Lastly, we went over the operation of the White Lightning strobes.

Production stills by Tiancong "Jacob" Huang