Chapter 2 Flashcards
What is the purpose of a lense?
Focus light unto the sensor of the camera.
What is the optical centre?
The middle of the lens - O
What is the Focal point?
The point where parallel rays are focused by the lens. - F
What is the focal length?
Distance from optical centre to focal point - denoted f.
What is the optical axis?
The line Oand F lies on.
What is the term g in camera terms?
The distance from an obejct to the lens.
What is the term b in camera terms?
distance from optical centre to where object rays meet inside camera
What is the depth of field?
How much an individual object can be moved and still remain in focus - rays have to stay within pixel.
What is aperture?
The size of the hole that lets light into the camera. Lower aperture= larger depth of field - not as much bluring think pin-hole camera.
What is exposure time?
The amount of time the aperture stays open and light is allowed to be registered by the CHIP. High exposure times give blur when objects move.
What is an ADC?
Analog to digital converter - converts light signal from Chip to number.
Explain picture from sensor to image.
Each cell in chip converted using ADC - the cell can be different bit values - e.g. 1 byte (8 bit) - into grey level values.
Name different image coordinate systems:
1) (row,column) 1-based left upper corner
2) (x,y) -0 based in left upper corner
3) (x,y) -0 based lower left corner
