Optics Vocab Flashcards
Image (pinhole cameras)
The image which appears on the screen of the pinhole camera and resembles the object
Object
The thing giving off light
Inverted (pinhole cameras)
Image is upside down
Focused
Sharp/well defined image
Real (pinhole cameras)
A type of image which can be formed on a screen as light rays pass through the image
Umbra
Full shadow with clear edges
Penumbra
Shadow containing some light and blurred edges
Light
White appearance, contains all colours of rainbow, waves or photons, carries energy
Visible light
A form of energy detectable by human eyes
Luminous sources
Produce their own visible light eg. sun, filament, candle
Illuminated objects
Don’t give our light but reflect light from luminous sources into our eyes. Most objects are illuminated
Speed of light
3x10 8 m/s
Shadow
Formed when some light rays continue and others are impeded by an object
Law of reflection
Angle of incidence = angle of reflection
Solar eclipse
Moon covers sun (total- whole centre covered, partial- partially covered, annular- ring (if moon is further away than normal))
Lunar eclipse
Moon in earths shadow, moon goes dark
Super imposed
Lots of images on top of each other
Refractive index
Tells us how optically dense a material is:
Speed of light in vacuum/speed of light in material (that it enters)
OR n= Vv/Vm
Critical angle
The angle at which light is refracted along the top of a prism Sin c (critical angle) = 1/n (refractive index) OR n=sin i/sin r (i bigger)
Total internal reflection
When a ray of light hits a transparent surface at more than the critical angle it is reflected
