Image Formation
Barrel vs pincushion distortion
Barrel distorts "out"
Pincushion distorts "in"
Linear perspective is determined by _____ not _____
object distance
focal length
Can you truly sharpen an image?
No, must be sharp at capture
Can only create illusion of sharpness
Most common FPS in the US
24 FPS (or 30)
Most common aspect ratio
Optimum pinhole diameter
Inches - sqrt f/141
MM - sqrt f/28
Image size is _____ proportional to focal length and _____ proportional to object distance
Directly
Inversely
Is raw or JPEG sharper?
JPEG, raw has less processing
How many pixels are in 1080p frame?
1920 x 1080
How many pixels are in a 4k frame?
3840 x 2160
2 types of aberration
Chromatic - all colors of light do not come to focus at the same point (corrected with achromatic doublet)
Spherical - when all the rays passing through a lens come to focus at different points
Binocular vision
2 forward facing eyes
Allows for depth perception
Sharpening workflow
Capture - loss of sharpness from optics, etc.
Creative - subjective visual emphasis
Output - printing causes loss of sharpness
Most common CODEC
H.264
3 frames in interframe compression
I - key frame
B - bidirectional frame
P - predictive frame
Hyperfocal distance
Closest distance that appears sharp when lens is focused on infinity
Closest distance that can be focused on and have an object at infinity appear sharp
3 keys to linear perspective
Horizon line
Vanishing point
Orthogonal lines
Pixel point vs pixel group processing
Point - altering a single pixel (ex removing dust)
Group - altering a pixel based on those around it (filtering, scaling)
3 kinds of choma subsampling
4:4:4 (most info)
4:2:2
4:2:0
3 characteristic of human eyesight that make video possible
Beta movement
Flicker fusion
Persistence of vision
Permissable circle of confusion
Largest circle that appears as a point
4 methods of achieving perspective
Depth of field, lighting, overlap, aerial haze, color, stereophotography, holography, linear perspective
3 types of Kernels, what do they do?
Blurring - reduces digital counts
Sharpening - increases contrast on edges
Edge detection
Rolling vs global shutter
Rolling shutter captures and outputs the frame from sensor to processing in a certain amount of time
Global shutter captures and outputs the entire scene all at once
Inter vs Intraframe compression
Inter - encodes the differences between frames
Intra - compresses each individual frame independently