Abstract: A dark field illumination device comprises an illumination light source, which emits illumination light rays, a light shielding plate, which is located between the sample and the illumination light source, and selectively shields the illumination light rays directly entering the observation optical system among the illumination light rays emitted from the illumination light source, an optical member, which directs, toward the sample, the illumination light rays passing outside the illumination light rays shielded by the light shielding plate, and a background member, which is disposed between the sample and the light shielding plate, and has a smooth surface on a side of the sample.

Abstract: There is disclosed an inverted microscope comprising an objective lens disposed under a sample, a tube lens which is disposed in a light path of an observation light emitted from the objective lens and which forms the observation light into an image, an incident light illumination optical device which is disposed between the objective lens and the tube lens, and which introduces incident light illumination into the light path of the observation light, and an input/output port which is disposed between the incident light illumination optical device and the tube lens, and which splits a light flux from the light path of the observation light or introduces the light flux into the light path of the observation light.

Abstract: The present invention broadly comprises a device, such as a slider, for performing phase contrast microscopy, the device containing a plurality of at least three phase contrast annuli. The slider is received into a microscope condenser mounted under a microscope stage and that is adapted to receive the device and align the device such that a phase contrast annulus is aligned with an appropriate microscope objective phase ring. The invention also comprises printed or engraved indicators or other markings indicating whether the bright field aperture or a particular phase contrast annulus is in position in the illumination path of the microscope. The invention further comprises a device for preventing the removal of the device from the condenser.

Abstract: There is provided an electronic component-recognizing device for taking an image of an electronic component brought to a component-sensing station, for recognition thereof. The component-sensing camera takes the image of the electronic component by utilizing reflected light from the electronic component. A lighting mechanism lights the electronic component. The lighting mechanism comprises a light-guiding element, a ring light guide, and a light source. The light-guiding element is arranged annularly such that the light-guiding element can diffuse illumination light and emit the diffused illumination light toward the electronic component obliquely from below. The ring light guide holds the light-guiding element. A light source supplies the illumination light to the light-guiding element.

Abstract: The invention relates to an optical system in the ray path of a confocal fluorescence microscope, comprising at least one laser light source (1, 2), a device positioned in the illuminating/detecting beam (3, 4, 5) for separating the exciting light (8) from the fluorescent light (9), an objective (10) arranged between the device and the object (7), and a detector (11) positioned downstream of the device situated in the detecting beam (5). The aim of the invention is to increase the fluorescence yield of the system while retaining its compact structure.

Abstract: The present invention broadly comprises a device, such as a slider, for performing phase contrast microscopy, the device containing a plurality of at least three phase contrast annuli. The slider is received into a microscope condenser mounted under a microscope stage and that is adapted to receive the device and align the device such that a phase contrast annulus is aligned with an appropriate microscope objective phase ring. The invention also comprises printed or engraved indicators or other markings indicating whether the bright field aperture or a particular phase contrast annulus is in position in the illumination path of the microscope. The invention further comprises a device for preventing the removal of the device from the condenser.

Abstract: The invention concerns an apparatus for implementing phase-contrast or modulation-contrast observation on microscopes with the aid of a modulator (7) arranged in each pupil plane in the observation beam path and containing at least one layer modifying the phase or amplitude, and of a stop (3) arranged in the illumination beam path. For stepless adaptation of the phase shift, the modulator (7) is mounted tiltably. The invention further concerns a method for implementing a defined phase shift.

Abstract: A microscope for use in total internal reflection fluorescence microscopy (TIRFM) is provided. The microscope includes a first white-light source for directing light along a first optical path; an annular slit member disposed in the first optical path, the annular slit member having an annular slit for blocking all but an annulus of light corresponding to the annular slit; and an objective lens for directing the annulus of light to a specimen such that TIRFM of the specimen is achieved. Also provided are various ways for converting the microscope to and from a TIRFM microscope and a conventional microscope.

Abstract: A microscope (10) having an improved light source assembly (40) that provides sufficient illumination for sophisticated microscopic applications while requiring so little power that it may be operated with a small, rechargeable battery pack (46) that provides over 40 hours of continuous operation from a single charge. The light source assembly (40) has a bulb life of approximately 100,000 hours and operates at temperatures significantly below the operating temperatures of conventional microscope bulbs.

Abstract: A novel microscope and method of obtaining images includes a combination of the conventional darkfield illumination technique with electronic image inversion (converting a positive to a negative image) and other improvements to further enhance the contrast and resolution of the final image. The microscope and method are referred to herein as Inverted Darkfield Contrast (IDC) and are believed to be particularly suitable for viewing live cells in real time with no staining or preparation.

Abstract: A direct-view optical microscope system is provided which uses high-energy light from a phenomenon known as non-resonant Raman scattering to illuminate a living biological specimen. One embodiment of the system combines two discrete light sources to form a combined incident light source for the microscope. The system includes a method and apparatus for modulating the intensity of the scattered light when two light waves are combined to produce the incident light. By varying the frequency of the two source light waves, the intensity of the combined Raman-scattered light can be modulated to achieve finer resolution.

Abstract: A microscope for use in total internal reflection fluorescence microscopy (TIRFM) is provided. The microscope includes a first white-light source for directing light along a first optical path; an annular slit member disposed in the first optical path, the annular slit member having an annular slit for blocking all but an annulus of light corresponding to the annular slit; and an objective lens for directing the annulus of light to a specimen such that TIRFM of the specimen is achieved. Also provided are various ways for converting the microscope to and from a TIRFM microscope and a conventional microscope.

Abstract: An optical arrangement in the beam path of a light source suitable for fluorescence excitation, preferably in the beam path of a confocal laser scanning microscope, with at least one spectrally selective element (4) to inject the excitation light (3) of at least one light source (2) in the microscope and to extract the excitation light (3) scattered and reflected on the object (10) or the excitation wavelength from the light (13) coming from the object (10) through the detection beam path (12) is characterized for variable configurations with the simplest construction in that excitation light (3, 9) of different wavelengths can be extracted by the spectrally selective element (4). Alternatively, an optical arrangement like this is characterized in that the spectrally selective element (4) can be adjusted to the excitation wavelength to be extracted.

Abstract: In performing an light emitting operation using a plurality of semiconductor light-emitting devices, these semiconductor light-emitting devices are lighted up such that the driving current is lessened and the life time of the devices is prevented from being shortened and lights can be emitted to a remote site without reducing an amount of lights. Semiconductor laser devices 23a to 23c, which emit lights through independent lenses 25a to 25c, are connected in series to each other and connected to a signal generating circuit 24, serving as a power supply, so as to perform pulse lighting, whereby making it possible to light up three semiconductor laser devices simultaneously at a driving current corresponding to one semiconductor laser device. A package of semiconductor laser devices 23a to 23c comprises three lead terminals, and an electrical connection to two lead terminals, which are electrically insulated from a metallic base, is established.

Abstract: An optical element change-over control apparatus is provided that has an optical element change-over member capable of holding a plurality of optical elements and rotating alternatively to locate a specific optical element on an optical path. A control element drives a driving element to rotate the optical element change-over member and counts positioning signals delivered from a positioning detecting element during a time interval that elapses from the instant that a point of origin of the optical element change-over member is first detected by an origin detecting element until the point of origin of the optical element change-over member is secondly detected by the origin detecting element, thereby detecting the number of change-over stages of the optical element change-over member.

Abstract: An optical device and microscope of simple construction are provided that are capable of readily attaining super resolution with good focusing performance. This comprises a light source means (2, 3, 4, 6, 8) that generates light of multiple different wavelengths, a light condensation means to focus lights of these multiple wavelengths on an object 1, and an emitted light detector means 17 for detection of light emitted from said object 1. Among said multiple lights of different wavelengths generated from said light source means, at least one light forms a condensed light pattern of multiple spatial modes. These multiple lights are condensed upon said object 1 such that part of the region of the condensed light pattern of said multiple spatial modes is made to spatially overlap with the condensed light pattern of the other light.

Abstract: The invention relates to an optical device comprising a stereomicroscope having a lens (4, 13), and a laser (5) which emits a laser beam (8) for machining a workpiece (9). The inventive device is characterised in that a tiltable mirror (10) is provided, by means of which the laser beam (8) can be guided through the lens (4, 13) over the workpiece (9).

Abstract: A microscope for use in total internal reflection fluorescence microscopy (TIRFM) is provided. The microscope includes a first white-light source for directing light along a first optical path; an annular slit member disposed in the first optical path, the annular slit member having an annular slit for blocking all but an annulus of light corresponding to the annular slit; and an objective lens for directing the annulus of light to a specimen such that TIRFM of the specimen is achieved. Also provided are various ways for converting the microscope to and from a TIRFM microscope and a conventional microscope.

Abstract: A method for generating a multicolor image of a specimen with a microscope is disclosed. The method comprises the step of determining the spacing of the focal planes of a first illuminating light beam that has a first wavelength and of a second illuminating light beam that has a second wavelength; the step of scanning the specimen with the first illuminating light beam and generating a first partial image; the step of performing a relative displacement, by an amount equal to the spacing, between the specimen and the focal plane of the illuminating light beam of the second wavelength; the step of scanning the specimen with the second illuminating light beam and generating a second partial image; and the step of superimposing the first and second partial images to yield the multicolor image. Further more a microscope and a confocal scanning microscope are disclosed.

Abstract: The invention concerns a microscope having an image sensor (5) for recording the microscope images. The specimen (3) to be examined can be scanned by means of a stop (2) in the beam path of the illumination unit and a positioning unit which moves the specimen (3) or the stop (2). Opening the stop (2) or removing it from the beam path permits the entire image to be scanned with the image sensor (5).

Abstract: An epi-illumination interference attachment according to Mirau that can be mounted onto the objective (1) of a microscope as a two-ray interference attachment module (12). The attachment has a reference mirror (6) and several beam splitters (8a-8d) which are affixed on a carrier such as turret plate (7). The beam splitters (8a-8d) show specific reflection/transmission characteristics (R/T values), especially 20/80, 35/65, 43/57, and 50/50. The reference mirror (6) shows, for instance a reflection value of 85 percent. With the installation according to this invention, objects (4) with very different reflection values can be observed and measured without any contrast problems.

Abstract: An illumination apparatus, having a light source that supplies illumination light, a collector lens that converts a divergent light flux emitted from the light source into a plurality of substantially parallel light fluxes, a fly-eye lens, comprised of a plurality of small lens elements and an exit surface, disposed at a rear focal position of the collector lens and a relay optical system that relays a pseudo plane light source which is formed on the exit surface of the fly-eye lens to an aperture stop or a surface conjugate to the aperture stop, where a focal length of at least one of the plurality of small lens elements is 8≦focal length ≦24, a radius of at least one of the plurality of small lens elements is 1≦radius ≦3 and a consistent unit of length is used for the focal length and radius.

Abstract: In the present invention, a transmission-illumination apparatus for use in a microscope has a transmission-illumination optical system comprising a condenser lens for radiating light emitted from a light source onto a sample, and an observation optical system including an objective lens for observing the sample. At least two shield members for controlling a shape of an aperture created in a pupil of the objective lens are disposed at or near positions conjugate with a pupil position of the objective lens. Thereby, a contrast can be successively varied without disposing a purpose-specific optical element, etc. in the observation optical system, and illumination with an optimal contrast can be provided for various samples.

Abstract: The substage illuminator is in the form of a housing having therein an opening disposed to register with the underside of a workpiece that is being inspected by optical gaging apparatus which is disposed to overlie the workpiece and which has an image inlet aperture registering with the opening in the substage housing. A collimating lens is mounted in the opening of the housing beneath an anti-reflection filter, and a light source which is mounted in or connected to the housing, projects a circular beam of light successively through the collimator lens and filter toward the underside of the inspected workpiece. The light source may be in the form of a plurality of radially spaced, circular arrays of LED's that can be selectively illuminated to control the diameter of the beam emitted thereby, or the source may comprise an L.C.D. aperture generator which may be energized to produce light beams of selectively different diameters.

Abstract: A stereomicroscope has a dark field illumination apparatus capable of irradiating a subject with the light from a light source at a high efficiency by providing an optical system through which regularly reflected light beams are overlapped with each other by an annular reflective member with less ununiformity of the illumination.

Abstract: An illuminator has a printed circuit board supporting a ring of light emitting diodes (LEDs). An annular Fresnel lens and the board are both mounted in a housing having a central though-hole for a camera field of view. The lens mixes light from the LEDs in the tangential direction and it also controls spread in the radial direction so there is uniform illumination over a target plane. Any individual point on the target plane receives illumination from over 25% of the light sources. The illuminator is thus particularly effective, compact, and suitable for a wide range of industrial applications. Choice of lens and the spatial arrangement allows versatility. The illuminator design is easily scaleable by changing the size and spacing between the light sources.

Abstract: The present invention concerns a double confocal scanning microscope having an illuminating beam path (1) of a light source (2) and a detection beam path (3) of a detector (4), and in order to eliminate at their cause the problems of reconstruction methods. To do so, at least one optical component (24, 25) acting on the illuminating and/or detection beam path (1, 3) is provided, and is configured in such a way that it influences the amplitude and/or phase and/or polarization of the light; and the characteristics of the double confocal illumination and/or detection are thereby modifiable.

Abstract: A differential interference contrast (DIC) microscope system is provided comprising: (a) an illumination source for illuminating a sample ; (b) a lens system for viewing the illuminated sample, including an objective, defining an optical axis; (c) at least one detector system for receiving a sample image; (d) mechanisms for wavelength multiplexing the shear direction or shear magnitude or both on the sample and demultiplexing the resultant DIC images on the detector; and (e) a mechanism for modulating the phase of the interference image. Various approaches are disclosed to accomplish wavelength multiplexing of shear direction and demultiplexing the two DIC images that result. It is possible for the two, wavelength multiplexed DIC images to differ in either or both shear direction or magnitude.

Abstract: Optical apparatus includes a first material that causes positive birefringent retardation under physical strain and a second material that causes negative birefringent retardation under physical strain. The first and second materials are arranged along a common line of sight so that under physical strain the combination of the first and second materials causes birefringent retardation having a magnitude that is less than the magnitude of the positive retardation caused by the first material and that is less than the magnitude of the negative retardation caused by the second material.

Abstract: A system for imaging is disclosed herein. The system has a numerical aperture (NA) preferably greater than 0.9, but greater than 0.65, and uses unique illumination entrances to collect reflected, diffracted, and scattered light over a range of angles. The system includes a catadioptric group, focusing optics group, and tube lens group. Illumination can enter the catadioptric optical system using an auxiliary beamsplitter or mirror, or through the catadioptric group at any angle from 0 to 85 degrees from vertical. The high NA catadioptric system can also have a relayed pupil plane, used to select different imaging modes, providing simultaneous operation of different imaging modes, Fourier filtering, and other pupil shaping operations.

Abstract: An illumination system (1) for a microscope, in which a first light source (2), a collector lens (3), an aperture diaphragm (4), and a condenser lens ((5) are arranged in the illumination beam path (6), is described. The illumination light is directed through the aperture diaphragm (4) via the condenser lens (5) into the object plane (9). Arranged in the illumination beam path (6) on the optical axis (20) is a second light source (8) that is imaged at infinity by the condenser lens (5).

Abstract: The present invention concerns a microscope having an illuminating beam path (1) of a light source (2), a detected beam path (3) of a detector (4), a component (5) combining the detected beam path (3), and at least two microscope objectives (7, 8) directed onto the specimen (6). In order to achieve enhanced detection efficiency, the present invention is characterized in that an optical component (14) arranged in the beam path (1, 3) has the property of acting on a portion of the illuminating and/or detected beam cross section in such a way that the combined detected light (15, 16) is guided in largely lossless fashion to the detector (4). Alternatively thereto, the microscope according to the present invention is characterized in that a polarizing beam splitter (19), arranged in the beam path (1, 3) and acting on the entirety of the illuminating and/or detected beam cross section, is provided.

Abstract: A microscope having a device for selectable illumination for observation of a specimen by ultraviolet light, DUV light, or by visible light, and which can keep ultraviolet light and visible light separate. The microscope includes a visible light illuminating system to illuminate a specimen with visible light, an ultraviolet light illuminating system to illuminate the specimen with ultraviolet light, a visible light observation system to observe the specimen illuminated by the visible light illuminating system, and an ultraviolet light observation system to observe the specimen by the ultraviolet light illuminating system.

Abstract: The invention concerns a microscope having an illumination beam path, in which a darkening of the illumination on the subject (21) is achieved by removing, or changing the position of, an optical component.

Abstract: A phase contrast observation device for observing a phase object (O), and phase apertures for same. The device comprises, in order along an optical axis (AX), a light source (LS) capable of providing light (L), an illumination optical system (G2 and G3) for condensing the light and illuminating the object, an aperture stop (AP) having an aperture (AO) therein, arranged in the illumination optical system, an objective lens system (G2 and G3) for converging light from the illuminated object and forming an image of the object. The device also includes one of a number of novel phase apertures (Ph1-Ph4) arranged at a position inside said objective lens conjugate to the aperture stop. The phase apertures of the present invention allow for high-contrast and low-contrast imaging regardless of the phase content of the object.

Abstract: A microscope for transmission viewing of a specimen, said microscope comprising a light source for producing a light beam; an objective lens positioned for focusing the light beam produced by said light source on an area of the specimen for illuminating said area; and a reflector means positioned for reflecting light transmitted through the specimen back through the illuminated area of the specimen.

Abstract: An epi-fluorescence microscope includes: a light guiding device that guides illuminating light emitted by a light source by reflecting the illuminating light to implement epi-lighting on a test piece, and guides fluorescent light excited by the illuminating light and generated from the test piece to an observation unit by allowing the fluorescent light to be transmitted; and an inclined member that is provided on an optical path of transmitted light which is a part of the illuminating light and has been transmitted through the light guiding device instead of being reflected by the light guiding device, and has a surface inclined relative to the optical path.

Abstract: Disclosed is a dark field illumination apparatus which is capable of performing a dark field illumination which exhibits a sufficient brightness and a sufficiently suppressed unevenness in brightness. The apparatus comprises a shaping system for shaping a light beam from a light source into approximately parallel beam having a ring- shaped section; a fly-eye optical device for forming a plurality of light source images in the vicinity of its exit plane based on the approximately parallel beam, the light source images being arranged circularly; and a light collection optical system for collecting light beams from the light source images and superposing them on an object plane.

Abstract: A stereomicroscope has a dark field illumination apparatus capable of irradiating a subject with the light from a light source at a high efficiency by providing an optical system through which regularly reflected light beams are overlapped with each other by an annular reflective member with less ununiformity of the illumination.

Abstract: A description is given of an illuminating device for a microscope (1), having a light source (2), an illuminating optical system (3) and an LCD (5) arranged in the illuminating beam path (4). The illuminating light is directed onto the object (6) from the light source (2) via the LCD (5), a transparent/opaque pattern being generated on the LCD (5) by means of a control and calculating device (7). The LCD (5) is arranged in a plane (AP′) which is conjugate with respect to the field diaphragm plane or aperture diaphragm plane (AP) and has a planar matrix composed of individual pixels arranged next to one another and of the same dimensions, the pixels each being constructed such that they can be driven individually to generate an arbitrary transparent/opaque pattern. The control and calculating device (7) is constructed as a computer with a graphics card.

Abstract: An optical unit switching apparatus having a type-display section for displaying types of all optical units mounted on a movable member for switching and moving the optical units; and indicators arranged corresponding to respective mounting positions for the optical units for indicating a type of the optical unit inserted into an optical path. Since these indicators are located at different positions with respect to the centers of the corresponding mounting positions for the optical units, the indicators point at different positions in the type-display section when switching operations are performed. Accordingly, the type of the optical unit presently inserted into the optical path can be recognized by printing the names and the like of the respective optical units at the positions pointed at by the indicators corresponding to the respective optical units.

Abstract: A removable head for an ophthalmic slit lamp assembly that replaces the conventional slit lamp microscope with a laser and binocular microscope combination. The optic axis of the laser is aligned to the optic axis of the binocular microscope so the optical head can be removed and used with another slit lamp assembly. An adaptor provides adjustable connection between the optical head and a microscope support arm of the slit lamp assembly. The adaptor consists of a base member and a frame member. The frame member is rotated and translated relative to the base member to align the optic axis of the optical head to the slit lamp optic axis.

Abstract: A lens housing has an axial bore containing a lens system for projecting through the bore the image of an illuminated object which is located beyond one end of the lens housing. The lens housing is surrounded by a lamp housing which contains a plurality of spaced lamps that are operable to direct spaced, parallel, collimated beams of light through an open end of the lamp housing, and toward the object that is to be illuminated. A paraboiloidal or ellipsoidal reflector, which is interposed between the lamp housing and the object, has in one end thereof a relatively large diameter opening which is releasably secured over the open end of the housing, and has in its opposite end a smaller opening registering with, and for accommodating a portion of the object that is to be illuminated. The collimated light beams are directed by the reflector onto the portion of the object at angles of incidence in the range of 40° to in excess of 90°.

Abstract: An illuminating system for an image processing measuring apparatus according to the present invention is composed on an inclined-incident illuminating device B mounted removably to a body tube and projecting obliquely a luminous flux to an object to be measured, a ring-shaped incident illuminating device mounted removably to the body tube and projecting a ring-shaped luminous flux to the object other than a vertical-incident illuminating device projecting the luminous flux emitted from an optical source from the direction just above the object, and a switching for switching the luminous flux emitted from the light source to either of the inclined-incident illuminating device and the ring-shaped incident illuminating device.

Abstract: A light transmitting device for use in a viewing apparatus or optical device, particularly a night vision device. The device is composed of a material which is capable of transmitting light from a remote source. Light from a visible indicator such as an LED is transferred through at least one outer flat to an inner flat of the device. The inner flat provides a signal to the user that the power supply is low. An additional outer flat and inner flat provides a signal to the user that the infrared illuminator is in operation. A projection formed along the outer periphery of the device prevents rotation and aids in assembling the device in a viewing apparatus. With the light transmitting device, there is no need for a separate device attached to the housing of an optical device for indicating power supply.

Abstract: A system for multiple mode imaging is disclosed herein. The system is a catadioptric system preferably having an NA greater than 0.9, highly corrected for low and high order monochromatic aberrations. This system uses unique illumination entrances and can collect reflected, diffracted, and scattered light over a range of angles. The system includes a catadioptric group, focusing optics group, and tube lens group. The catadioptric group includes a focusing mirror and a refractive lens/mirror element. The focusing optics group is proximate to an intermediate image, and corrects for aberrations from the catadioptric group, especially high order spherical aberration and coma. The tube lens group forms the magnified image. Different tube lens groups can be used to obtain different magnifications, such as a varifocal tube lens group to continuously change magnifications from 20 to 200.times.. Multiple imaging modes are possible by varying the illumination geometry and apertures at the pupil plane.

Abstract: An optical microscope has an illuminator from which light emanates to illuminate an object under examination, and an auxiliary magnifying lens unit which magnifies an image of the object formed by the light reflecting from the object. A reflective cover is connected to the bottom of the ocular lens unit of the microscope. An auxiliary magnifying unit, made up of the auxiliary magnifying lens mounted in a casing, is disposed within the reflective cover adjacent the bottom of the ocular lens unit. The illuminator is located between the reflective cover and the casing of the auxiliary magnifying unit. The auxiliary magnifying lens is thus shielded from the illuminator. The light emitted from the illuminator is prevented from propagating directly to the auxiliary magnifying lens (along any straight line from the illuminator) or indirectly to the auxiliary magnifying lens via reflection from the inner wall of the reflective cover. Accordingly, a clear image of the object is produced.

Abstract: An apparatus and method for imaging fired bullets and/or cartridges for forensic examination, which facilitate mounting of the ammunition to be imaged. The apparatus comprises a mounting support including a fired bullet holding device and a fired cartridge holding device, a microscope, an illumination device and a mechanical device for selectively aligning the optical axis of the microscope with a bullet section or the longitudinal axis of the cartridge showing its head surface. The bullet holding device comprises a rotary member extending through a mounting support and ending with an adjustable bullet holder for maintaining the bullet in a desired angular orientation with respect to a transverse reference plane aligned with the optical axis of the microscope, while the rotary member is being rotated about its rotation axis to scan the imaged surface area.

Abstract: An illumination apparatus with a specimen slide holder, an illumination source, an optical cavity producing multiple reflection of illumination light to a specimen comprising a first and a second reflective surface arranged to achieve multiple reflections of light to a specimen is provided.

Abstract: The apparatus has a fired cartridge mounting device for holding the cartridge substantially aligned with a longitudinal axis with a primer surface of the cartridge substantially perpendicular to the axis, a cartridge microscope mounted with its optical axis substantially parallel to the longitudinal axis, a focusing mechanism for focusing the microscope to image a breech face impression on the primer surface and a firing pin impression surface in the primer surface, and an axisymmetric light source mounted to project axially symmetric light onto the breech face impression and the firing pin impression surface about the longitudinal axis. Images of the breech face and the firing pin impressions can be used for comparative analysis independently of an angular orientation of the cartridge held by the mounting device.