Cinematography • Ep. 02 • Lens Parameters

Introducing the second episode of our Cinematography Series for Digital Artists. This time, we focus our attention on Lens Parameters.

Cinematography is Everything

In the first video we established what is Cinematography and why it is such an essential skill for everyone working in Game, Visual Effects and Animation.

In order to bring our virtual worlds and creations to life, we must look beyond our digital skills. We need to master light and we need to understand how cameras capture our 3D scenes. Wihtout light there’s simply nothing to see. And without cameras there’s no image.

In other words, what you create doesn’t exist without Cinematography. As simple as that.

The Parameters

In this schematic representation of the camera, the parameters are represented in blue and yellow, respectively related to light and composition. As for the elements in orange, those are not parameters but visual by-products.

Most lenses, real or virtual, provide 3 points of control:
• Focus (or Focal Point)
• Focal (or Focal Length)
• Aperture

Let’s explore these 3 lens parameters in details…

Aperture

The Aperture is actually a series of blades inside the lens. It’s originally designed to control the amount of light which eventually reaches the sensor, just like the iris in our eyes. The wider the aperture, the higher the exposure, and vice versa. Aperture is expressed in ‘stops’ and the difference between 2 stops is twice the amount of light.

Focal Length

The Focal Length determines 2 distinct factors:

• Field of View
It’s the Angle ‘seen’ by the camera.
The lower the value of the focal length, the wider the angle.

• Optical Compression
Defines the perceived compression of the scene’s depth, or the perceived distance between objects. A higher focal length will optically compress the depth of the scene. A wide focal length will make objects look further apart than what the actually are. A Neutral, or Standard focal length will provide a perception similar to that of the naked eye.

Focal Point

The Focal Point, or Focus, is simply the distance between the sharpest point of your image and the camera. It’s expressed in meters or feet.

Depth of Field

These 3 parameters combined will affect the Depth of Field.

The Depth of Field is not a parameter created by design. It’s a visual artefact. It’s the visual consequence of Focal Length, Focal Poitn and Aperture, interacting together.

The Depth of Field is the resulting area of sharpness around the Focal Point.