Lecture 4 - Video Analysis Flashcards
what is the key difference of quantitative and qualitative analysis
quantitative : analysis of measurement of movement
qualitative : (usually visual) analysis of the form of the movement
what is frame rate
number of pictures (frames) per second
what is the unit of frame rate
fps or Hz
what is aperture
size of the opening in the lens
what does larger aperture mean
allows more light in, but reduces the depth of field
what is aperture measured in
f-stops
what is shutter
open and closes to expose sensor to light
what does slower shutter mean
more light, but can cause motion blur
what do fast movements need in terms of shutter speed
fast shutter (and lots of light0
what lighting is best, and what may be needed if indoors
sunlight is best, indoors may need flood lighting
what is ISO
sensitivity to light
what does ISO do
can lighten darker pictures, but adds graininess
in terms of ISO what are the best quality pictures
best image quality at low ISO values, but need lots of light
what are the 3 components of exposure
- aperture
- shutter
- ISO
why is plane of movement important and how is this avoided
out of plane movement can cause perspective error
- set up camera on tripod perpendicular to plane, avoid tilting, especially if using calibration
