Glossary

M

magnification
The ratio of image to object size. It can be measured in the X,Y directions orthogonal to the optical axis (lateral magnification) or in the Z directions parallel to the optical axis (axial magnification).
See also: lateral magnification, axial magnification
magnification changer
An optical component that can be shifted into the optical path to alter the magnification of the system.
See also: magnification
magnification of an eyepiece
The magnification imparted by the eyepieces, commonly 10-15x.
See also: magnification, eyepieces
magnified analysis of proteome
see expansion microscopy
magnifier
A lens of lens system designed to create a magnified image of an object and intended for visual observation, such as an eyepiece or jeweler's loupe.
See also: eyepiece, magnification, magnification changer
marginal ray
The ray that can be traced from the optical axis (in the center of the field of view) to the outermost edge of the lens aperture.
See also: ray, ray tracing, characteristic rays, principal ray, geometric optics, chief ray
marking of optical components
Standardized labels for components such as objective lenses, which have different colored bands to indicate magnification and immersion-type.
See also: objective lens
mass extinction coefficient
see extinction coefficient
maximum intensity projection (MIP)
A resultant image formed by taking the highest-intensity value at each particular pixel position across an image stack, such as a Z stack or timelapse. Useful for visualization, cropping, and analysis purposes.
See also: image, image stack, Z stack
mechanical stage
A type of stage that allows for the precise and independent translation of the sample in the X and Y directions using a pair of rotatable knobs, and typically using a rack and pinion design.
See also: stage
mechanical tube length
The distance between the objective-locating nosepiece flange and eyepiece-locating observation tube flange of a microscope, it was standardized at 160 mm for fixed tube length systems by the Royal Microscopical Society (RMS).
See also: tube, eyepiece-locating observation tube flange, objective-locating nosepiece flange, fixed tube length system, optical tube length
mercury arc lamp
Light source wherein light is produced by the arcing of electricity through vaporized mercury contained in a bulb.
Synonyms: mercury lamp
See also: light source, lamp, illuminator, bulb, metal-halide arc lamp
mercury lamp
see mercury arc lamp
metal-halide arc lamp
A light source wherein light is produced by the arcing of electricity through a mixture of vaporized metal halides and mercury contained in a bulb.
See also: light source, lamp, illuminator, bulb, mercury arc lamp
Michel Lévy chart
see second order blue
Michel-Lévy color chart
A chart relating the interference colors produced by a birefringent sample observed using polarized light microscopy with the sample thickness to provide a measure of the birefringence.
Synonyms: Michel Lévy chart
See also: birefringence, polarized light microscopy, interference, polarized light, interference colors
microchannel plate (MCP)
An electron multiplier made from resistive material which is used to detect photons and then amplify the resulting signal into a quantized value.
See also: area detector
micrograph
An image acquired using a microscope.
Synonyms: microscope image
See also: image
microinjection
A method for injecting biological or genetic material, drugs, and other substances directly into a cell via a microscopic pipette.
microlens
A small lens with a diameter smaller than one millimeter. It is often used in an array for applications such as light field microscopy.
See also: lens, light field microscopy
micromanipulator
A device enabling precise mechanical interaction with a sample under a microscope.
micrometer
One one-thousandth of a millimeter. This is a common length scale for subjects of microscopy such as cells.
Synonyms: µm
micrometer eyepiece
An eyepiece featuring a labelled measurement reticule that appears overlaid over the image and can be translated using a micrometer screw. It enable visual measurement of sample features.
Synonyms: filar eyepiece, micrometer screw eyepiece
See also: eyepiece
micrometer screw eyepiece
see micrometer eyepiece
micrometry
The use of an eyepiece graticule/reticle to make linear measurements of objects viewed using a microscope.
Synonyms: linear measurements
See also: graticule, micrometer eyepiece
microphotography
The field of acquiring photographic images of small objects with the use of a microscope.
microprojector
A microscope combined with projection optics which can display a large-format view of a specimen.
microscope
An optical instrument that enables visualization of objects and features that are too small to observe by eye - principally on the scale of micrometers.
See also: micrometer, optical train, microscope base, inverted microscope, upright microscope
microscope base
The primary body or base of a microscope that serves as the main hub for the attachment of other optical components, such as illuminators, cameras, observation tubes, etc. It contains the body tube and is designed for to accept intermediate tubes, observation tubes, etc.
Synonyms: microscope stand, stand
See also: microscope, observation tube, intermediate tube, body tube
microscope entrance pupil
The plane of the virtual image of the limiting aperture stop as seen by the object, its diameter defines the range of rays that will be accepted by the microscope from the object.
Synonyms: entrance pupil of the microscope
See also: microscope exit pupil
microscope exit pupil
The image of the limiting aperture stop as viewed from the image space, it can be a real or virtual image depending on the design. It is usually located after the eye lens and coinciding with the entrance pupil of the human eye.
Synonyms: exit pupil of the microscope, Ramsden disc
See also: microscope entrance pupil, eye lens, conjugate planes, aperture plane
microscope field-of-view
see field of view
microscope image
see micrograph
microscope lamp
A type of illuminator consisting of a lamp that is optically coupled to a microscope.
See also: lamp, light source, illuminator
microscope stand
see microscope base
microtome
An instrument capable of slicing very thin section of a sample such as thick tissue, with 4 µm considered a standard thickness for histology.
Mie scattering
A type of elastic scattering that occurs upon interaction of light with a spherical particle comparable in size to its wavelength, it occurs predominantly in the forward direction.
See also: elastic scattering, Rayleigh scattering
minimum resolvable distance
The minimum distance at which objects can be distinguished from one another. It may be defined using a standard such as the Rayleigh criterion.
Synonyms: spatial resolution, resolving power
See also: resolution, numerical aperture
mirror
An optical component that reflects light (specular reflection).
See also: lens, catoptric
modulation contrast
A label-free brightfield contrast technique using illumination through a slit aperture (positioned in an aperture plane in the illumination optics) and detection through an intensity modulator (in a conjugate aperture plane in the detection optics). It enables visualization of phase gradients.
Synonyms: Hoffman modulation contrast
See also: Nikon advanced modulation contrast, label-free
modulation transfer function (MTF)
The real part of the complex-valued optical transfer function (OTF), it describes the relative contrast with which different spatial frequencies are transmitted, irrespective of phase effects.
See also: optical transfer function, contrast transfer function, phase transfer function
Moiré fringes
see Moiré patterns
Moiré patterns
An emergent lower frequency pattern resulting from overlaying a pair of regular patterns.
Synonyms: Moiré fringes
See also: interference, aliasing
molar absorption coefficient
see extinction coefficient
monochromat
An optical component designed for a small range of specific wavelengths.
See also: objective lens, monochromatic radiation
monochromatic aberrations
Optical aberrations that occur even if only a single wavelength is observed. These include distortion, astigmatism, spherical aberration, and coma.
See also: aberration, astigmatism, coma, spherical aberration, distortion, curvature of image field
monochromatic radiation
Electromagnetic radiation of a specific wavelength.
See also: radiation, electromagnetic spectrum
monochromaticity
see phase difference
monocular microscope
A microscope featuring a single eyepiece.
See also: microscope, eyepiece, observation tube, monocular tube
monocular tube
An observation tube that transfers a microscope image along a single path, in contrast to a binocular or trinocular tube which can selectively transmit images to eyepieces and/or a camera, for example.
See also: observation tube, binocular tube, trinocular tube, quadrocular tube, eyepiece
mounting medium
A chemical solution used as an immersive medium when mounting a specimen for observation (e.g., when mounting using microscope slide and coverslip). Matching the refractive index of the immersion medium of the objective to the mounting medium reduces optical aberrations and improves resolution.
See also: immersion medium, coverslip, refractive index
multi-alkali photomultiplier tube (MA PMT)
A photomultiplier tube featuring a multi-alkali photocathode material, providing improved sensitivity to red - near-infrared wavelengths. It is popular for point-scanning confocal microscopy.
Synonyms: multialkali PMT, SbNa2 KCs PMT
See also: photomultiplier tube, point-scanning confocal microscopy
multi-immersion objective (MI)
An objective lens that can be adjusted via correction collar for use with immersion media covering a wide range of refractive indices.
See also: correction collar, immersion medium, immersion objective, objective lens, refractive index
multi-mode fiber
A light-transmitting fiber featuring a much wider core than a single mode fiber, thereby transmitting multiple modes of light simultaneously. The beam exiting a multi-mode fiber exhibits a flatter profile compared to the sharp gaussian profile of a single-mode fiber beam.
See also: single-mode fiber
multi-view fusion
A technique in which the sample is imaged from multiple perspectives and the resulting data is combined to form a reconstruction with more isotropic resolution. This is commonly used in light sheet fluorescence microscopy, which routinely uses multiple objectives to detect light.
See also: light sheet fluorescence microscopy
multialkali PMT
see multi-alkali photomultiplier tube
multidimensional image dataset
see image stack
multiphoton
see multiphoton microscopy
multiphoton excitation
Excitation of a system by simultaneous interaction with photons that are 2- or 3- times the wavelength of the usual one-photon excitation wavelength.
See also: multiphoton microscopy, one-photon excitation, two-photon excitation, three-photon excitation
multiphoton microscopy
A non-linear technique in which a system is excited by wavelengths that are roughly 2- or 3- times the usual 1-photon excitation wavelength. The high photon flux necessary for multiphoton excitation usually only occurs at the focus of the objective lens, providing optical sectioning. Deep imaging is further supported by the decreased scattering of the longer wavelength light.
Synonyms: multiphoton
See also: confocal laser scanning microscopy, multiphoton excitation, two-photon excitation, three-photon excitation, second harmonic generation microscopy, third harmonic generation microscopy, incident optical unit, optical sectioning
multiple-beam interference
An optical phenomenon accomplished by situating two surfaces of high reflectivity in close proximity. By using a lens to converge beams which have undergone multiple-reflection between these surfaces, an interference pattern can be observed, allowing for precise topographical measurements to be made in the specimen.
See also: interferometry
µm
see micrometer