If we have a 5K Fresnel projecting through a 12x12 diffusion, what is considered the source?

• A. The 5K Fresnel
• B. The 12x12 Diffusion
• C. The Light Itself
• D. The Subject

Answer: (B)

The key idea is that the apparent light source is defined by what the subject actually sees. In this setup, the light energy from the 5K Fresnel is being passed through a 12x12 diffusion, and it’s the diffusion that the camera and subject perceive as the source of illumination. The diffusion is the element that shapes and distributes the light reaching the subject, so it determines the apparent size of the source, which in turn controls the softness of the shadows and the wrap of the light.

So, even though the Fresnel behind it is generating the light, the diffusion in front is what you identify as the source for practical lighting decisions, because it’s the last piece in the path that creates the light on the subject.