ISO 10934:2020

DRAFT INTERNATIONAL STANDARD
ISO/DIS 10934
ISO/TC 172/SC 5 Secretariat: DIN
Voting begins on: Voting terminates on:
2019-10-09 2020-01-01
Microscopes — Vocabulary for light microscopy
ICS: 01.040.37; 37.020
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Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 Terms and definitions relating to light microscopy . 1
3.2 Terms and definitions relating to advanced techniques in light microscopy .45
Bibliography .54
Index .55
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Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
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organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
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.org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 172, Optics and photonics, Subcommittee
SC 5, Microscopes and endoscopes.
This first edition cancels and replaces ISO 10934-1:2002 and ISO 10934-2:2007, which have been
combined and technically revised.
The main changes compared to the previous edition are as follows:
— update of the title;
— added new terms for light microscopy: focal length of normal tube lens, objective field number,
pixel, pixel size, Airy unit, excitation wavelength, excitation wavelength band, detection wavelength
band, OSTD added as new terms;
— added new terms for advanced techniques in light microscopy: coherent anti-stokes Raman
scattering microscopy, stimulated Raman scattering microscopy, structured illumination
microscope, super-resolution microscopy, localization microscopy, stimulated emission depletion
microscopy, super-resolution SIM, light sheet microscopy, digital holographic microscopy, optical
coherence (tomography) microscopy;
— Terms amended: diffraction limit of resolving power, resolution;
— Editorially revised.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/members .html.
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DRAFT INTERNATIONAL STANDARD ISO/DIS 10934:2019(E)
Microscopes — Vocabulary for light microscopy
1 Scope
This document specifies terms and definitions to be used in the field of light microscopy and advanced
techniques in light microscopy.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http: //www .electropedia .org/
— ISO Online browsing platform: available at http: //www .iso .org/obp
3.1 Terms and definitions relating to light microscopy
3.1.1
Abbe test plate
device for testing the chromatic (3.1.4.2) and spherical aberration (3.1.4.7) of microscope (3.1.99)
objectives (3.1.106)
Note 1 to entry: When testing for spherical aberration, the cover glass thickness for which the objective is best
corrected is also found. The test plate consists of a slide on which is deposited an opaque metal layer in the
form of parallel strips arranged in groups of different width. The edges of these strips are irregularly serrated to
allow the aberrations to be judged more easily. In its original and most common form, the slide is covered with a
wedge-shaped cover glass, the increasing thickness of which is marked on the slide. Additional versions without
the cover glass and/or with reflective stripes are also in use.
3.1.2
Abbe theory of image formation
explanation of the mechanism by which the microscope (3.1.99) image (3.1.75) is formed
Note 1 to entry: It assumes coherent illumination and is based on a three-step process involving diffraction.
a) First step: the object diffracts light coming from the source.
b) Second step: the objective collects some of the diffracted beams and focuses them, according to the laws of
geometrical optics, in the back focal plane of the objective to form the primary diffraction pattern of the object.
c) Third step: the diffracted beams continue on their way and are reunited; the result of their interference is
called the primary image of the microscope.
This explains the necessity for the maximum number of rays diffracted by the object to be collected
by the objective, so that they may contribute to the image. Fine detail will not be resolved if the rays it
diffracts are not allowed to contribute to the image.
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3.1.3
aberration
〈material and geometric form〉 deviation from perfect imaging by an optical system, caused by the
properties of the material of the lenses (3.1.87) or by the geometric forms of the refracting or reflecting
surfaces
3.1.4
aberration
〈optical system〉 failure of an optical system to produce a perfect image (3.1.75)
3.1.4.1
astigmatism
aberration (3.1.4) which causes rays in one plane containing an off-axis object (3.1.104) point and the
optical axis (3.1.107) to focus at a different distance from those in the plane at right angles to it
3.1.4.2
chromatic aberration
aberration (3.1.4) of a lens (3.1.87) or prism (3.1.119), due to dispersion (3.1.47) by the material from
which it is made
Note 1 to entry: This defect may be corrected by using a combination of lenses made from glasses or other
materials of different dispersion.
3.1.4.2.1
axial chromatic aberration
aberration (3.1.4) by which light (3.1.88) of different wavelengths is focused at different points along
the optical axis (3.1.107)
3.1.4.2.2
lateral chromatic aberration
chromatic difference of magnification
aberration (3.1.4) by which the images (3.1.75) formed by light (3.1.88) of different wavelengths, although
they may be brought to the same focus (3.1.65) in the optical axis (3.1.107), are of different sizes
3.1.4.3
coma
aberration (3.1.4) in which the image (3.1.75) of an off-axis point object (3.1.104) is deformed so that the
image is shaped like a comet
3.1.4.4
curvature of image field
aberration (3.1.4) resulting in a curved image field (3.1.54.4) from a plane object field (3.1.54.5)
Note 1 to entry: Curvature of the image field is particularly obvious with objectives of high magnification and
large numerical aperture, which have a restricted depth of field. It may largely be eliminated by additional
correction.
3.1.4.5
distortion
aberration (3.1.4) in which lateral magnification (3.1.90.8) varies with distance from the optical axis
(3.1.107) in the image field (3.1.54.4)
3.1.4.5.1
barrel distortion
negative distortion
difference in lateral magnification (3.1.90.8) between the central and peripheral areas of an image
(3.1.75) such that the lateral magnification is less at the periphery
EXAMPLE A square object in the centre of the field thus appears barrel shaped (i.e. with convex sides).
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3.1.4.5.2
pincushion distortion
positive distortion
difference in lateral magnification (3.1.90.8) between the central and the peripheral areas of an image
(3.1.75) such that the lateral magnification is greater towards the periphery
EXAMPLE A square object in the centre of the field thus appears pincushion shaped (i.e. with concave sides).
3.1.4.6
monochromatic aberrations
collective term for all aberration (3.1.4) outside the Gaussian space which appear for monochromatic
(3.1.123.2) light (3.1.88)
Note 1 to entry: The monochromatic aberrations are: spherical aberration, coma, astigmatism, curvature of
image field and distortion.
3.1.4.7
spherical aberration
aberration (3.1.4) resulting from the spherical form of the wavefront arising from an object (3.1.104)
point on the optical axis (3.1.107), on its emergence from the optical system
Note 1 to entry: As a consequence, the rays emanating from an object point on the optical axis at different angles
to the axis, or rays entering the lens parallel to the optical axis but at differing distances from it, intersect the
optical axis in the image space before (undercorrection) or behind (overcorrection) the ideal image point formed
by the paraxial rays.
3.1.5
achromat
〈lens element〉 lens (3.1.87) in which the axial chromatic aberration (3.1.4.2.1) is corrected for two
wavelengths
EXAMPLE One wavelength less than about 500nm, the other greater than about 600 nm.
3.1.6
achromat
〈microscope objective〉 microscope (3.1.99) objective (3.1.106) in which chromatic aberration (3.1.4.2) is
corrected for two wavelengths and spherical aberration (3.1.4.7) and other aperture-dependent defects
are minimized for one other wavelength which is usually about 550nm
EXAMPLE One wavelength less than about 500 nm, the other greater than about 600nm.
Note 1 to entry: This term does not imply any degree of correction for curvature of image field; coma and
astigmatism are minimized for wavelengths within the achromatic range.
3.1.7
Airy pattern
image (3.1.75) of a primary or secondary point source (3.1.135.1) of light (3.1.88) which, due to diffraction
(3.1.41) at a circular aperture (3.1.10) of an aberration-free lens (3.1.87), takes the form of a bright disc
surrounded by a sequence of concentric dark and bright rings
3.1.7.1
Airy disc
diffraction disc
central area bounded by the first dark ring of the Airy pattern (3.1.7)
Note 1 to entry: The Airy disc contains 84 % of the energy of the Airy pattern.
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3.1.7.2
Airy unit
AU
diameter of the theoretical first minimum of the Airy pattern (3.1.7) in the low numerical aperture
(3.1.10.4) approximation
λ
ref
Note 1 to entry: AU=12, 2
NA
3.1.8
anisotropic
having a non-uniform spatial distribution of properties
Note 1 to entry: In polarized light microscopy, this usually refers to the preferential orientation of optical
properties with respect to the vibration plane of the polarized light.
3.1.9
apertometer
device for measuring the numerical aperture (3.1.10.4) of microscope (3.1.99) objectives (3.1.106)
3.1.10
aperture
area of a lens (3.1.87) which is available for the passage of light (3.1.88)
Note 1 to entry: In microscopy, it is usually expressed as the numerical aperture.
3.1.10.1
angular aperture
〈microscopy〉 maximum plane angle subtended by a lens (3.1.87) at the centre of an object field (3.1.54.5)
or image field (3.1.54.4) by two opposite marginal rays when the lens is used in its correct working
position
Note 1 to entry: The term may be qualified by the side of the lens to which it refers (e.g. object side, illumination
side, image side).
3.1.10.2
condenser aperture
illuminating aperture
aperture (3.1.10) of the illuminating system which is defined by the diameter of the illuminating aperture
diaphragm (3.1.38.6)
3.1.10.3
imaging aperture
aperture (3.1.10) of the imaging system
Note 1 to entry: The imaging aperture is generally defined by the numerical aperture of the objective.
3.1.10.4
numerical aperture
NA
number originally defined by Abbe for objectives (3.1.106) and condensers (3.1.28), which is given by the
expression n sin u, where n is the refractive index (3.1.125) of the medium between the lens (3.1.87) and
the object (3.1.104) and u is half the angular aperture (3.1.10.1) of the lens
Note 1 to entry: Unless specified by “image-side”, the term refers to the object side.
3.1.11
aplanatic
corrected for spherical aberration (3.1.4.7) and coma (3.1.4.3)
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3.1.12
apochromat
〈lens element〉 lens (3.1.87) in which axial chromatic aberration (3.1.4.2.1) is corrected for three
wavelengths
EXAMPLE Wavelengths of about 450nm, 550nm and 650nm.
3.1.13
apochromat
〈microscope objective〉 microscope (3.1.99) objective (3.1.106) in which the chromatic aberration (3.1.4.2)
is corrected for three or more wavelengths and the spherical aberration (3.1.4.7) and other aperture-
dependent defects are minimized for about 550nm as with achromats (3.1.6)
EXAMPLE Wavelengths of about 450nm, 550nm and 650nm.
Note 1 to entry: This term does not imply any degree of correction for curvature of image field.
3.1.14
aspherical
not forming part of the surface of a sphere
Note 1 to entry: This term is also used to describe the shape of a refracting or a reflecting surface designed to
minimize spherical aberration and some other aberrations.
3.1.15
beam splitter
means whereby a beam of light (3.1.88) may be divided into two or more separate beams
3.1.16
birefringence
Δn
quantitative expression of the maximum difference in refractive index (3.1.125) due to double refraction
(3.1.48)
3.1.17
bright field
system of illumination (3.1.73) and imaging in which the direct light (3.1.45) passes through the objective
(3.1.106) aperture (3.1.10) and illuminates the background against which the image (3.1.75) is seen
3.1.18
bulb
envelope of a lamp (3.1.85), which is usually out of glass or fused silica
Note 1 to entry: This term is commonly used to describe the lamp itself.
3.1.19
catadioptric
having optical arrangements оr optical elements which operate by both reflection and refraction
3.1.20
catoptric
having optical arrangements оr optical elements which operate by reflection
3.1.21
centring telescope
auxiliary telescope
two-stage magnifier, designed for use in place of the eyepiece (3.1.52) to enable an image (3.1.75) of the
back focal plane (3.1.62.1) of the objective (3.1.106) to be inspected
Note 1 to entry: The centring telescope is used principally for adjustment of the microscope illuminating system,
especially with phase contrast and modulation contrast. May also be used for conoscopic observation.
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3.1.22
circle of least confusion
smallest diameter image (3.1.75) spot formed from a point object (3.1.104) when spherical aberration
(3.1.4.7) and astigmatism (3.1.4.1) are present
3.1.23
clear focusing screen
sheet of clear glass or plastic material used for focusing (3.1.67) in photography and photomicrography
(3.1.115) in which a figure on the screen (3.1.132) (e.g. cross lines) serves to define the plane (3.1.117 )
in which the aerial image (3.1.75.1) observed with a focusing magnifier (3.1.92.1) shall be located
3.1.24
coarse adjustment
focusing mechanism (3.1.68) designed to make large and rapid alterations in the distance along the
optical axis (3.1.107) between the object (3.1.104) and the objective (3.1.106)
3.1.25
coating of optical surfaces
deposit of one or more thin dielectric and/or metallic layers on a surface of an optical element for the
purpose of decreasing or increasing reflection and/or transmission
EXAMPLE Optical elements such as a lens, mirror, prism, or filter.
3.1.26
collector
lens (3.1.87) which serves to project a suitably sized image (3.1.75) of the source (3.1.135) into a given
plane (3.1.117) (e.g. in Köhler illumination (3.1.73.3) into the aperture plane (3.1.117.1) of the condenser
(3.1.28))
Note 1 to entry: Sometimes known as the “lamp collector”.
3.1.27
compensator
retardation plate (3.1.130) of fixed or variable optical path length difference (3.1.108.1) used to measure
the optical path length differences within an object (3.1.104)
Note 1 to entry: Many types of compensator exist, often designated by the name of their originator e.g. Babinet,
Berek, Senarmont.
3.1.27.1
first-order red compensator
first-order red plate
sensitive tint plate
retardation plate (3.1.130) producing an optical path length difference (3.1.108.1) of one wavelength,
giving rise to the interference colour (3.1.82) having the typical tint of the first-order red (3.1.57)
3.1.27.2
half-wave compensator
half-wave plate
retardation plate (3.1.130) producing an optical path length difference (3.1.108.1) of half a wavelength,
the reference wavelength being taken to be 550nm
3.1.27.3
quarter-wave compensator
quarter-wave plate
retardation plate (3.1.130) producing an optical path length difference (3.1.108.1) of a quarter of a
wavelength
Note 1 to entry: The reference wavelength is selected according to the application and is individually indicated.
When oriented at 45° to the plane of polarization, it changes plane-polarized light into circularly-polarized light
and vice versa.
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3.1.27.4
quartz-wedge compensator
retardation plate (3.1.130) consisting of a wedge of quartz (or two such wedges in the subtraction
position) producing optical path length differences (3.1.108.1) continuously variable between 0 λ and 3 λ
or 4 λ along its length
Note 1 to entry: This property results in the production of a series of interference colours in the form of fringes
perpendicular to the length of the wedge. With monochromatic light, the coloured fringes are seen as alternating
dark and bright bands.
3.1.28
condenser
part of the illuminating system of the microscope (3.1.99) which consists of one or more lenses (3.1.87 )
(or mirrors) and their mounts, usually containing a diaphragm (3.1.38), and designed to collect, control
and concentrate radiation (3.1.123) into the illuminating numerical aperture (3.1.10.4)
Note 1 to entry: In bright field microscopy by epi-illumination, the objective serves as its own condenser.
3.1.28.1
Abbe condenser
condenser (3.1.28) of simple design introduced by Abbe, in which there is only limited correction (3.1.33)
for spherical aberration (3.1.4.7) and none for chromatic aberration (3.1.4.2)
3.1.28.2
achromatic-aplanatic condenser
condenser (3.1.28) in which chromatic aberrations (3.1.4.2) and spherical aberrations (3.1.4.7) have
been reduced
Note 1 to entry: Achromatic-aplanatic correction is particularly advantageous for high numerical aperture, oil
immersion condensers.
3.1.28.3
cardioid condenser
dark-field condenser (3.1.28.4) for transmitted-light illumination (3.1.73.6), in which the correction
(3.1.33) for spherical aberration (3.1.4.7) and coma (3.1.4.3) is calculated for a reflecting surface with
the shape of a cardioid of revolution
Note 1 to entry: In practice, the correction is achieved by using a zone of a spherical surface which differs
imperceptibly in its corrective effect from a true cardioid surface.
3.1.28.4
dark-field condenser
dark-ground condenser
condenser (3.1.28) designed for dark-field (3.1.35) microscopy
Note 1 to entry: For transmitted-light microscopy, this condenser is a separate component; for reflected-light
microscopy, it is generally within the mount of the objective, surrounding the imaging system of the objective.
3.1.28.5
pancratic condenser
condenser (3.1.28) containing a variable “zoom” (pancratic) lens (3.1.87) which allows the size of the
illuminated field (3.1.54.3) at the object (3.1.104) to be varied while the illuminated field diaphragm
(3.1.38.5) remains of constant size
Note 1 to entry: The size of the illuminating aperture varies inversely with that of the illuminated field at the
object, and the product of both sizes remains a constant.
3.1.28.6
phase-contrast condenser
condenser (3.1.28) designed for phase contrast (3.1.32.4) microscopy which forms on the phase plate
(3.1.112) in the back focal plane (3.1.62.1) of the objective (3.1.106) a suitably sized image (3.1.75) of a
diaphragm (3.1.38) (generally annular) positioned in the front focal plane (3.1.62.2) of the condenser
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3.1.28.7
substage condenser
condenser (3.1.28) designed to fit beneath the stage (3.1.136) of a microscope (3.1.99)
3.1.28.8
swing-out top lens condenser
condenser (3.1.28) designed so that its top lens (3.1.87) can conveniently be removed from the optical
path by operating a lever, thus increasing the condenser’s (3.1.28) focal length (3.1.61) in order to
increase the area of the illuminated field (3.1.54.3) and decrease the illuminating numerical aperture
(3.1.10.4) for use with objectives (3.1.106) of low magnification (3.1.90)
3.1.28.9
universal condenser
condenser (3.1.28) designed for multiple contrast techniques such as bright field (3.1.17), dark-field
(3.1.35), phase contrast (3.1.32.4), differential interference contrast (3.1.32.2.1), polarized light (3.1.88.1)
and modulation contrast (3.1.32.3)
3.1.29
conjugate planes
planes (3.1.117) perpendicular to the optical axis (3.1.107) which are imaged onto another in accordance
with the rules of geometrical optics
3.1.30
conoscopic figure
interference pattern of curves linking points of equal retardation (3.1.129), formed in the back focal
plane (3.1.62.1) of the objective (3.1.106) when an optically anisotropic (3.1.8) object (3.1.104) is placed
between crossed polars (3.1.118.2) or, exceptionally, parallel polars (3.1.118.3)
3.1.31
conoscopy
observation of the conoscopic figure (3.1.30) by means of a pinhole diaphragm (3.1.38) or a centring
telescope (3.1.21) in place of the eyepiece (3.1.52), or by means of a Bertrand lens (3.1.87.2)
3.1.32
contrast
distinction between regions in an image (3.1.75) due to differences in brightness and/or colour
3.1.32.1
interference contrast
〈term〉 contrast (3.1.32) in the image (3.1.75) caused mainly by interference
3.1.32.2
interference contrast
〈phenomenon〉 enhancing the contrast (3.1.32) between features having different optical path lengths
(3.1.108)
3.1.32.2.1
differential interference contrast
contrast (3.1.32) due to double-beam interference (3.1.81.1) in which two waves which fall on the object
plane (3.1.117.5) or image plane (3.1.117.3) are separated laterally by a distance similar to the minimum
resolvable distance (3.1.128.2)
Note 1 to entry: This kind of contrast is characterized by an impression of unilateral oblique illumination.
Variations in optical path length due to gradients in surface relief (reflected light) or in physical thickness or
refractive index (transmitted light) appear as relief contrast in the image.
3.1.32.2.2
Nomarski differential interference contrast
form of differential interference contrast (3.1.32.2.1) using Nomarski prisms (3.1.119.2)
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3.1.32.3
modulation contrast
contrast (3.1.32) technique due to Hoffman which uses a modulator in the back focal plane (3.1.62.1) of
the objective (3.1.106) or in a succeeding conjugate plane (3.1.29), and a slit aperture (3.1.10) in the front
focal plane (3.1.62.2) of the condenser (3.1.28)
Note 1 to entry: The modulator is a filter composed of three regions: a dark region, a grey region onto which the
slit in the condenser is imaged and a bright region. The modulator influences the direct light and diffracted light
in order to increase contrast.
3.1.32.4
phase contrast
form of interference contrast (3.1.32.2) (in its widest sense) due to Zernike, in which the image contrast
(3.1.32) of a phase object (3.1.111) is enhanced by altering phase (3.1.110) and amplitude of the direct
light (3.1.45) with respect to those of the diffracted light (3.1.40) and which is achieved by the action of
a phase plate (3.1.112), usually in the form of an annulus, placed in the back focal plane (3.1.62.1) of the
objective (3.1.106) (or in a succeeding plane conjugate (3.1.29) with this) conjugate with an appropriate
illuminating aperture diaphragm (3.1.38.6) in the front focal plane (3.1.62.2) of the condenser (3.1.28)
Note 1 to entry: The phase plate has two properties: it shifts the phase of the direct light by 90° and absorbs some
of its intensity. Contrast is achieved by conversion of phase differences within the light leaving the object into
intensity differences in the image. Two kinds of phase contrast are available, depending on the characteristics
of the phase plate; in positive phase contrast, objects which retard the phase of the diffracted light by a small
amount appear darker than the background, while in negative phase contrast they appear brighter.
3.1.32.5
relief contrast
form of contrast (3.1.32) which presents gradients of geometrical or optical path length differences
(3.1.108.1) in the object (3.1.104) in the form of a distribution of brightness in the image (3.1.75) which
gives an impression of relief (3.1.126)
Note 1 to entry: This impression occurs because the distribution of brightness in a relief contrast image is similar
to the distribution of light and shadow in the image of a three-dimensional object illuminated from one side.
3.1.33
correction
process whereby the aberrations (3.1.4) of an optical system are minimized
3.1.33.1
correction class
type of correction (3.1.33) of an optical system (achromatic, plan, etc.)
3.1.33.2
correction collar
mechanism provided on some objectives (3.1.106) in order to adapt their correction (3.1.33) for spheri
...