Optical instruments

thumb|A direct-readout theodolite, manufactured in the Soviet Union in 1958 and used for topographic surveying

thumb|250px|Figure 1. The light path through a Michelson interferometer. The two light rays with a common source combine at the half-silvered mirror to reach the detector. They may either interfere constructively (strengthening in intensity) if their light waves arrive in phase, or interfere destructively (weakening in intensity) if they arrive out of phase, depending on the exact distances between the three mirrors.

thumb|A photometer A photometer is an instrument for measuring photometric quantities such as luminous flux, illuminance, or luminance.

combined electronic theodolite and electronic distance meter; used in surveying and building construction

optical instrument used to establish or check points in the same horizontal plane

instrument using light waves for image viewing

upright=1.5|thumb|Operating principle of an optical polarimeter. 1. Light source 2. Unpolarized light 3. Linear polarizer 4. [[Linearly polarized light 5. Sample tube containing chiral molecules under study 6. Optical rotation due to molecules 7. Rotatable linear analyzer 8. Detector]]

measurement device for objective color measurements

thumb|alt=A common spherometer.|A common spherometer. A spherometer is an instrument used for the precise measurement of the radius of curvature of a curved surface. Originally, these instruments were primarily used by opticians to measure the curvature of the surface of a lens.

medical device, microscope with a light source that can be projected into a linear beam

right|thumb|A cathetometer

thumb|250px|right|T100 autocollimatorAn autocollimator is an optical instrument for non-contact measurement of angles. They are typically used to align components and measure deflections in optical or mechanical systems. An autocollimator works by projecting an image onto a target mirror and measuring the deflection of the returned image against a scale, either visually or by means of an electronic detector. A visual autocollimator can measure angles as small as 1 arcsecond (4.85 microradians), while an electronic autocollimator can have up to 100 times more resolution.

A rhinoscope (or nasoscope) is a thin, tube-like instrument used to examine the inside of the nose. A rhinoscope has a light and a lens for viewing and may have a tool to remove tissue. thumb|Endoscopic rhinoscope |alt=Photo of rhinoscope used to visualise the nasopharynx and oropharynx through the nose

eyewear used in experimentation that inverts the wearer's view

thumb|right|Gloss meter in action

thumb|Dipleidoscope A dipleidoscope is an instrument used to determine true noon; its name comes from the Greek for double image viewer. It consists of a small telescope and a prism that creates a double image of the sun. When the two images overlap, it is local true noon. The instrument is capable of determining true noon to within ten seconds.

A dynameter is an instrument that measures the magnification of a telescope. It is usually a double-image micrometer used to measure the diameter of the image of the object glass. The magnifying power is found by comparing the actual diameter of the glass with the measured diameter of the image of the glass. thumb|350px|left|thumb|350px|center|

type of ammeter