Introduction
In this chapter we'll talk about Antialiasing (Sampling) settings in the context of achieving two effects which mimic physical cameras - DoF (Depth of Field) and Motion Blur. We'll cover them briefly, as we've already covered them in detail in the topic about Physical Camera (DoF and MB).
Image Sampling
Depth of Field
- Primary Parameter to affect DoF is F-number
- Also known as F-Stop or Aperture setting
- The Focal Length also plays a role in determining how far the distance is between completely in focus and completely out of focus within the shot
- Adjust the F-number will change the exposure of the shot
- Lower numbers mean more light will be taken into the camera and the render will be brighter
- Higher numbers mean less light makes it into the camera and the render will be darker
Motion Blur
- Primary Parameter that affects Motion Blur is a camera’s Shutter Speed
- Shutter Speed is how long the camera is open to expose the image sensor (or film) to capture an image
- Measured in fractions of a second
- Becomes Shutter Angle and Shutter Offset when using a cinema camera over a photography camera
Effects
Anti-Aliasing for Depth of Field
- The higher Max Subdivs and lower Threshold (from AA Quality) will improve the quality of your Depth of Field effect
- A higher Shading Quality (Min shading rate) will put more rays to secondary shading effects and less towards primary AA rays (which affects Depth of Field)
Shading Quality: 6%
AA Quality: 1-4 Threshold: 0.02
Shading Quality: 6%
AA Quality: 1-12 Threshold: 0.005
Anti-Aliasing for Motion Blur
- The noise in the motion blur is reduced with a higher Max subdivs amount
- The Threshold value controls how many samples are used within the min/max range. The lower the threshold, the closer the samples get to the max amount.
AA Quality Min/Max: 1/4 Threshold: 0.02
AA Quality Min/Max: 1/24 Threshold: 0.005