Mirrors and Lenses in Optical Instruments

• Optical Instruments are devices that extend human vision through the use of mirrors and lenses to reflect and refract light and form images.
• The word "camera" evolves from a Latin term meaning "dark chamber".
• The mechanisms of a camera are based on the fundamentals of reflection.
• The film surface of a camera records the image
• An adjustable diaphragm then regulates the amount of light that enters a lens and shutter just before the light sensor.
• The function of the shutter is to expose the light sensor to a consistent amount of light.
• In the case of digital cameras, instead of using film, images are recorded on a digital sensor array known as a charge-coupled device (CCD) or complementary metal oxide semiconductor (CMOS). This sensor creates a pixel map based on the electric charge generated when photons slam into a sensitive material (photoelectric effect).
• A telescope is an optical device that has the ability to make faraway objects appear much closer.
• The larger the aperture, the lighter the telescope collects and brings to focus, and the brighter the final image.
• The more "megapixels" the camera has, the more dots of light are stored and the higher the image resolution.
• A binocular telescope, or binoculars, is composed of two identical mirrors mounted side by side and aligned to point accurately in the same direction, allowing the viewer to use both eyes when viewing distant objects.
• Objective Lens Assembly - is located at the "big end" of the binocular, which gathers light from object and forms the image at the image plane.
• Eyepiece Lens Assembly - is the part that is placed by the eyes, which allows the examination image at the image plane. It has a focusing mechanism that allows the viewer to move either eyepiece assembly or an intermediate "transfer" lens, which in turn focuses the eyepiece onto the
• Image Orientation Correction - is commonly known as the prism assembly, which insure that the image is properly oriented and not inverted or laterally reversed. The prism assembly of large binoculars enables the eyepieces to be 45 degrees or 90 degrees to the main optical tube.