ASTM E883-11(2024)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E883 − 11 (Reapproved 2024)
Standard Guide for
Reflected–Light Photomicrography
This standard is issued under the fixed designation E883; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope mine the applicability of regulatory limitations prior to use.
Specific precautionary statements are given in X1.7.
1.1 This guide outlines various methods which may be
1.5 This international standard was developed in accor-
followed in the photography of metals and materials with the
dance with internationally recognized principles on standard-
reflected-light microscope. Methods are included for prepara-
ization established in the Decision on Principles for the
tion of prints and transparencies in black-and-white and in
Development of International Standards, Guides and Recom-
color, using both direct rapid and wet processes.
mendations issued by the World Trade Organization Technical
1.2 Guidelines are suggested to yield photomicrographs of Barriers to Trade (TBT) Committee.
typical subjects and, to the extent possible, of atypical subjects
2. Referenced Documents
as well. Information is included concerning techniques for the
enhanced display of specific material features. Descriptive
2.1 ASTM Standards:
material is provided where necessary to clarify procedures.
E7 Terminology Relating to Metallography
References are cited where detailed descriptions may be
E175 Terminology of Microscopy (Withdrawn 2019)
helpful. E768 Guide for Preparing and Evaluating Specimens for
Automatic Inclusion Assessment of Steel
1.3 The sections appear in the following order:
E1951 Guide for Calibrating Reticles and Light Microscope
Referenced documents 2
Magnifications
Terminology 3
2.2 Other Standard:
Significance and use 4
Magnification 5
MSDS Mercury-Material Safety Data Sheet
Reproduction of photomicrographs 6
Optical systems 7
3. Terminology
Illumination sources 8
Illumination of specimens 9
3.1 Definitions—For definitions of terms used in this guide,
Focusing 10
see Terminologies E7 and E175.
Filters for photomicrography 11
Illumination techniques 12
4. Significance and Use
Instant-processing films 13
Photographic materials 14
4.1 This guide is useful for the photomicrography and
Photographic exposure 15
Photographic processing 16 photomacrography of metals and other materials.
Keywords 17
4.2 The subsequent processing of the photographic materi-
Suggestions for visual use of metallographic Appendix
microscopes X1
als is also treated.
Guide for metallographic photomacrography Appendix
X2
5. Magnification
Electronic photography Appendix
X3
5.1 Photomicrographs shall be made at preferred
magnifications, except in those special cases where details of
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the the microstructure are best revealed by unique magnifications.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
1 3
This guide is under the jurisdiction of ASTM Committee E04 on Metallogra- The last approved version of this historical standard is referenced on
phyand is the direct responsibility of Subcommittee E04.03 on Light Microscopy. www.astm.org.
Current edition approved April 1, 2024. Published April 2024. Originally Available from United States Environmental Protection Agency (EPA), William
approved in 1982. Last previous edition approved in 2017 as E883 – 11(2017). DOI: Jefferson Clinton Bldg., 1200 Pennsylvania Ave., NW, Washington, DC 20460,
10.1520/E0883-11R24. http://www.epa.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E883 − 11 (2024)
5.2 The preferred magnifications for photomicrographs, are: 7.5 The resolution of the microscope depends primarily on
25×, 50×, 75×, 100×, 200×, 250×, 400×, 500×, 750×, 800×, the numerical aperture of the objective in use (1) . The term
and 1000×. empty magnification is used to describe high magnifications
(above approximately 1100 times the numerical aperture of an
5.3 Magnifications are normally calibrated using a stage
objective), which have been shown to offer no increase in
micrometer. Calibration procedures in Guide E1951 should be
image resolution. Nevertheless, some types of information,
followed.
such as the distance between two constituents, may be more
easily obtained from microstructures examined at moderate
6. Reproduction of Photomicrographs
empty magnifications.
6.1 Photomicrographs should be at one of the preferred
8. Illumination Sources
magnifications. A milli- or micrometre marker shall be super-
imposed on the photomicrograph to indicate magnification, in
8.1 Metallographic photomicrography typically uses Köhler
a contrasting tone. The published magnification, if known,
illumination. To obtain Köhler illumination, an image of the
should be stated in the caption.
field diaphragm is focused in the specimen plane, and an image
of the lamp filament or arc is focused in the plane of the
6.2 Photomicrograph captions should include basic back-
aperture diaphragm. Specific steps to obtain Köhler illumina-
ground information (for example, material identification,
tion vary with the microscope used. The manufacturer’s
etchant, mechanical or thermal treatment details) and should
instructions should be followed closely.
briefly describe what is illustrated so that the photomicrograph
can stand independent of the text. 8.2 For incandescent lamps, the applied voltage determines
the unit brightness and the color temperature of the source.
6.3 Arrows or other markings, in a contrasting tone, shall be
Evaporated tungsten blackens the envelope, resulting in dimin-
used to designate specific features in a photomicrograph. Any
ished brightness and color temperature as the lamp ages.
marking used shall be referenced in the caption.
Tungsten-halogen lamps minimize envelope blackening, main-
taining constant brightness and color temperature for most of
7. Optical Systems
their life. The high brightness and 3200 K color temperature of
7.1 Microscope objectives are available in increasing order
these lamps makes them especially suitable for color photomi-
of correction as achromats, semiapochromats (fluorites) and
crography.
apochromats (see Terminologies E7 and E175). Plan objectives
8.3 With arc sources, brightness per unit area is substan-
are recommended for photographic purposes because their
tially higher than that from any incandescent source. Their
correction provides a flatter image. The objective lens forms an
spectral output contains high energy spikes superimposed on a
image of the specimen in a specific plane behind the objective
white-light continuum. They also contain significant ultraviolet
called the back focal plane. (This is one of several possible real
(UV) and infrared (IR) emissions that should be removed for
image planes, called intermediary planes, where reticles may
eye safety (and for photographic consistency, with UV); see
be inserted as optical overlays on the image.)
8.4, 11.3.1, and 11.5.2.
7.2 The eyepiece magnifies the back focal plane (or other) 8.3.1 Xenon arcs produce a spectral quality close to daylight
intermediary image for observation or photomicrography. Eye- (5600K), with a strong spike at 462 nm. Strong emissions in
pieces are sometimes also used to accomplish the full correc- the IR should be removed. Xenon arcs that do not produce
tion of the objective’s spherical aberration and to improve the ozone are recommended.
flatness of field. 8.3.2 Carbon arcs have a continuous output in the visible
portion of the spectrum, with a color temperature near 3800K
7.2.1 The pupil of the observer’s eye must be brought to
and a strong emission line at 386 nm.
coincidence with the eyepoint of the visual eyepiece to view
8.3.3 Mercury arcs have strong UV and near-UV output,
the entire microscopical image. High-eyepoint eyepieces are
and are particularly useful to obtain maximum resolution with
necessary for eyeglass users to see the entire image field.
a blue filter. The color quality is deficient in red; it cannot be
7.2.2 Most microscopes have built-in photographic capa-
balanced for color photomicrography. Warning—Mercury has
bilities that use an alternate image path through the microscope
been designated by EPA and many state agencies as a hazard-
leading to a camera attachment port or to a viewscreen. A
ous material that can cause central nervous system, kidney, and
projection eyepiece delivers the image to the camera port or
liver damage. Mercury, or its vapor, may be hazardous to
screen.
health and corrosive to materials. Caution should be taken
7.3 Intermediate lenses (relay or tube lenses) are often
when handling mercury and mercury-containing products. See
required to transfer the specimen image from the intermediary
the applicable product Material Safety Data Sheet (MSDS) for
plane of the objective to that of the eyepiece. They may also
details and EPA’s website (http://www.epa.gov/mercury/
add their own magnification factor, either fixed or as a zoom
faq.htm) for additional information. Users should be aware that
system.
selling mercury or mercury-containing products, or both, in
your state may be prohibited by state law.
7.4 The objective, the eyepiece, and the compound micro-
scope (including any intermediate lenses) are designed as a
single optical unit. It is recommended to use only objectives
The boldface numbers in parentheses refer to the list of references at the end of
and eyepieces which are intended for the microscope in use. this standard.
E883 − 11 (2024)
8.3.4 Zirconium arcs have strong spectral output lines in the diameter. This can be observed by removing the eyepiece and
near IR, requiring filtration. Within the visible region, they are inspecting the back of the objective, either directly or with a
rated at 3200K color temperature. pinhole eyepiece. The aperture diaphragm should never be
used as a light intensity control.
8.4 Arc lamps require heat protection for filters and other
optical components, and certainly for eye safety. Infrared 9.5 See Fig. 1 for an illustration of a typical vertical
removal may be obtained by: “hot” mirrors in the illumination illumination system.
beam to reflect IR while transmitting visible light; heat-
absorbing filters to transmit visible light while absorbing IR, 10. Focusing
for example, solid glass filters or liquid-filled cells.
10.1 Sharp focus is necessary to obtain good photomicro-
8.5 A detailed discussion of illumination sources and the graphs.
quality of illuminants is given by Loveland (2).
10.2 There are two systems for obtaining sharp focus:
8.6 Some advice on using metallographic microscopes for ground-glass focusing and aerial image focusing.
visual observation has been compiled in Appendix X1.
10.2.1 For ground-glass focusing, relatively glare-free sur-
roundings and a magnifier up to about 3× are required. To
9. Illumination of Specimens
focus, the focusing knob is oscillated between underfocus and
9.1 Photomicrographs are made with a compound micro- overfocus in succeedingly smaller increments until the image is
scope comprised at least of an objective lens and an eyepiece sharp.
with a vertical illuminator between them. Field and aperture 10.2.2 There are four possible variations for focusing an
diaphragms, with a lamp and lamp condenser lenses, are aerial image.
integral parts of the system. The microscope should allow 10.2.2.1 The simplest case is a transparent spot on a
sufficient adjustment to illuminate the field of view evenly and ground-glass containing a fiduciary mark in the film plane. The
to completely fill the back aperture of the objective lens with specimen image is focused to coincide with the fiduciary mark,
light. using a magnifying loupe of about 3× to 5×. When the focus is
correct, the specimen image and the fiduciary mark will not
9.2 The vertical illuminator is a thin-film-coated plane glass
move with respect to each other when the operator’s head is
reflector set at 45° to the optical axis behind the objective. It
moved.
reflects the illumination beam into the objective and transmits
10.2.2.2 A second case uses a reticle fixed within the optical
the image beam from the objective to the eyepiece. In some
system at an intermediary plane. Focusing is a two-step
microscopes prism systems are used to perform this function.
process: focus the eyepiece on the reticle; bring the image into
9.3 The field diaphragm is an adjustable aperture which
focus against the reticle figure.
restricts the illuminated area of the specimen to that which is to
10.2.2.3 In the third case, a reticle is inserted into a focusing
be photographed. It eliminates contrast-reducing stray light.
eyepiece. Depending on equipment used, this can be either a
The field diaphragm is also a useful target when focusing a
two or three-step process: focus the reticle within the eyepiece;
low-contrast specimen.
next, set the proper interpupiliary distance, if required (some
9.4 The aperture diaphragm establishes the optimum bal- equipment requires a specific interpupiliary distance for eye-
ance between contrast, resolution, and depth of field. It should piece focus to coincide with camera focus); then focus the
be set to illuminate about 70 % of the objective’s aperture image coincident with the reticle.
FIG. 1 Vertical Illuminating System for a Metallurgical Microscope
E883 − 11 (2024)
10.2.2.4 The fourth case uses a single-lens reflex camera filter is used with a color complementary to that of the feature
body, where the camera focusing screen is the plane of (for example, a cyan filter for reddish copper plating; a blue for
reference. An eyepiece magnifier for the camera is an impor- yellow carbonitride particles). When maximum detail in a
tant accessory for this case. An aerial image focusing screen is colored phase must be shown, choose a filter with the same
preferred.
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