Optics And Vision Exam Flashcards
(62 cards)
Define Transparent
Describes materials that allow light to pass through with little or no reflection; for example glass
Define Opaque
Describes materials that do not allow
light to pass through; for example, wood, metal, cardboard, etc
Define Reflection
Is the changing of direction of light as it hits an opaque material
Define Umbra
The fully shaded region of a shadow
Define Penumbra
The partially shaded region of a shadow, formed by some light passing an opaque object
Define Specular Reflection
Reflection off smooth surfaces
Define Diffuse Reflection
Reflection of light off an uneven surface, which results in light scattering in many directions
Define Real Image
An image that appears on the same side of a concave mirror as the object; light rays pass through the object location and the image can be projected on to a screen
Define Virtual Image
An image that appears to be on the other side of a plane mirror; light rays do not pass through the image location
Define Refraction
Change in direction of light as it travels from one material to another
Define Visible Light Spectrum
Colours of visible light which can be seen by the eye; the colours seen in a rainbow or when light is split by a prism
Define Electromagnetic Radiation
All forms of radiated energy: visible light, infrared radiation, ultraviolet radiation, radio waves, X-rays, etc
Define Wavelength
Distance between the top or peak of one wave to the peak of the next
Define Ray
A directed straight line that represents the path followed by light
Define Illuminance
The amount of light arriving at one place per unit area
Types of Lenses (Describe)
Convex lens - curves outward, thicker in middle
Concave lens - curves inward, thicker at edges
Eye lens - focuses light on your retina so you can see a clear image
Camera lens - focuses light on your CCD matrix to illuminate pixels
General - a piece of glass/plastic light goes through
Define Retina
Special lining on the back of your eye; when light hits the retina, receptor cells send messages to the brain, which are translated into an image
Define Aperature
Hole or opening that lets light in a camera
Define Diaphragm
Part that changes the size of the aperture of camera’s lens; it varies the amount of light that reaches the film or photosensitive elements
Define Pupil
Opening in the eye that lets light in
Define CCD Matrix
A combination of Charged Coupled Device cells in a camera which has a similar function to the retina in the eye
Define Iris
Band of muscle in your eye that controls the size of the pupil and the amount of light entering your eye
Define Myopia
Nearsightedness
Define Hyperopia
Farsightedness