Glossary of Terms

Digital Cameras

Digital Cameras

 

Aperture
A space where light passes through an optical or digital instrument.

Auto Brightness
Allows the correct white balance, on a subject, instead of requiring the operator to adjust white balance manually.

Auto Focus
The ability of a camera to attain the correct focus on a subject, instead of requiring the operator to adjust focus manually.

Brightness
The luminous quality of a color along a continuum from pure black to pure white.

C-Mount Lens
A type of lens mount commonly found on movie cameras, television cameras, and trinocular microscope phototubes.

Cat. 5 Cable
Carries the video (analog) signal to the wall plate for further distribution of the signal to room devices such as TVs and projectors. The cable also carries power to the camera.

CCD Camera
A Charge-Coupled Device. In a CCD sensor, every pixel’s charge is transferred through a very limited number of output nodes to be converted to voltage, buffered, and sent off-chip as an analog (video) signal. All of the pixel can be devoted to light capture, and the uniformity of the output is high.

Chrominance
Portion of a video signal that carries hue and saturation color information.

CMOS Camera
Complementary Metal Oxide Semiconductor. In a CMOS sensor, each pixel has its own charge-to-voltage conversion, and the sensor often includes digitization circuits, so that the chip outputs digital bits which may reduce the area available for light capture. The capture chip requires less off-chip circuitry for basic operation.

Digital Video Recorder (DVR)
A device that records video without videotape to a hard-drive -based digital storage medium. The term includes stand-alone set-top boxes and software for personal computers which enables video capture and playback to and from disk.

Exposure
The amount of light reaching the imaging chip of a camera and is regulated by an internal iris or may be adjusted by using Applied Vision software.

Eyepiece Adapter
Attaches a camera with a microscope, making it a digital microscope and allows the camera to be closely aligned with the eyepiece of the microscope.

F-Stop
A camera lens opening (aperture) setting indicated by the f-number. This is the quantitative measure of lens speed.

Fluorescent Control
Will reduce the flicker caused by the fluorescent lights in a room and improves some dim light problems.

Focal Distance
The space between the lens of the camera and the surface of the object being converted into an image.

Focal Point
In cameras, as focal distance decreases the magnification increases.

Frame
One complete still image of video media.

Frame Rate
The number of times per second the image is refreshed. (NTSC 30 frames per second; PAL 25 frames per second)

Freeze
Will cause an image to be fixed (not live).

Hanover Bars
In PAL format, this alternation of color information can lead to an undesirable picture.

Image Resolution
A measurement of the quality of a video image based on the number of pixels that make up that image.

Iris
Adjusts the brightness of the image

Joint Photographic Experts Group (JPEG)
An international standard for still picture data compression.

Kensington Lock and Slot
A small hole found in the base of the camera and is used for attaching a lock secured in place with a key or pin device.

Laser Alignment
When laser is activated it ensures proper document orientation by indicating where a document should be placed for best viewing on the table below the camera. Laser displays for five seconds when the camera is first powered on.

Light Emitting Diode (LED)
The light source does not generate significant heat, nor destroys living specimens.

Light Sensitivity
The amount of incident light needed to activate the camera chip; the smaller the number the less light needed to produce an image on the camera.

Luminance
The black and white portion of a video signal representing picture contrast and brightness.

Megapixel
One million pixels, used as a measure of the resolution of digital cameras.

Pixel
The smallest element in a graphic image. Picture quality increases as the number of pixels increase.

RJ-45
Connectors on either end of the Cat. 5 cable provided with a camera, and it provides S-video, composite video, power, and RS-232 control, between the camera and the wall plate.

RJ-232
Found on a wall plate and is used to connect the camera to the control system such as Crestron or AMX.

Universal Serial Bus (USB) Adapter
An accessory allowing the conversion of an analog signal to a digital signal.

Universal Serial Bus (USB) Controller
A standard connection to interface devices such as a digital camera and a digital microscope to a computer, projector, interactive white board, etc.

Video Cassette Recorder (VCR)
Records images captured on camera or from an analog source.

Video Output Composite
The format of an analog television signal before it is combined with a sound signal.

Wall Plate
Provides the connecting site for the signal being transmitted from the camera, and allows output of a composite or S-Video signal, which in turn may be connected to a projector, TV, VCR or DVR.

White Balance
Adjusting a camera’s light filtering system to ensure that the camera accurately records true colors.

Zoom
To change the focal length to/from wide-angle and telephoto.

Microscopes

Microscopes

 

Abbe Condenser
A moveable lens system under the stage that can be moved up and down vertically, regulating the amount of light with an adjustable iris to control the beam diameter from the light source. It is very useful at magnifications above 400x.

Achromatic Lens
A combination of lenses made of different glass, used to produce images free of color distortion.

Adapter
A removable power cord that can be used as a standard wall plug in source of power for the instrument or as a charger of batteries in cordless units.

Aperture
A space where light passes through an optical or digital instrument.

Binocular Head
Two eyepieces, usually on a slide mechanism and can rotate 360°. The interpupillary distance is adjusted side-to-side, by sliding the eyepieces towards and away from each other.

Brightness
The luminous quality of a color along a continuum from pure black to pure white.

Coarse Focus
This knob is located on the side of the microscope frame, usually below the stage, which allows the observer to move the objective lens up and down. It is used in conjunction with the fine focus knob.

Coaxial Controls
Consists of two knobs where one smaller knob (fine adjust) is centered on top of another, larger knob (coarse adjust), both on the same axle.

Comparison Microscope
Contains two sets of objectives with a binocular head enabling side-by-side viewing of two different specimens. This is perfect for teaching forensics and comparative sciences.

Compound Microscope
A modern high-powered compound microscope has multiple objective lens within a single eye tube, and a series of three or four objective lenses on the ‘head’ which can be rotated into place. The image produced is a two dimensional (2-D) image.

Condenser
In compound microscopes, a lens found in or below the stage that concentrates the light on a specimen and increases the resolution.

Cordless Microscope
Can be operated for approximately 40 hours between charges and are typically illuminated by a LED system that uses rechargeable batteries.

Depth of Field
The area between the nearest object that is in focus and the furthest object in focus.

Diaphragm
Regulates the intensity of light entering through the slide and into the objective lens.

Digital Microscope
A microscope with a built in digital camera with a digital output such as a USB and can be display images on a PC, projector, or TV.

DIN (Deutsche Industrie Normen)
Represents an international standard for microscope objectives. This standard specifies the exact threading and focal length, and insures compatibility with lenses from any microscope manufacturer in the world.

Diopter
Allows for a difference in eyesight acuity between two users, the two eyes of a single user, and between a camera and eyepiece.

Disc Diaphragm
Regulates the light intensity entering through the slide and into the objective lens by a series of 6 or 8 openings (apertures) of increasing diameter, located just below the stage.

Dissecting Microscope
Designed for looking at large objects and allows the viewer a 3-D image. Also known as a Stereo Microscope.

Doublet Lens
A lens used in wide field 10x eyepieces to obtain better color enhancement.

Dual Opposing Head
Two eyepieces, each of which are at 45o to the head of the microscope, and set at 180° from each other. This allows two observers to use the microscope simultaneously.

Eyepiece (ocular)
The lens nearest to the eye.

Eyepiece Pointer
A fine hair ‘pointer’ inside the eyepiece which goes about half way across the visual field. The purpose of the pointer is to place a specific part of the field at the end of the pointer, allowing the user to share it with another user.

Field Diaphragm
An iris type light control, located between the light source and the sub-stage condenser, allowing even greater control of light.

Fine Focus
A smaller knob used to adjust the fine focus of a specimen in conjunction with the coarse adjustment knob.

Field of View
The diameter of light in a circle seen through the microscope.

Floating Stage
A microscope stage which may be moved in multiple directions with the microscope slide clipped on its surface.

Fluorescent
A whitish light source based on a gas discharge process. Primary benefit is the amount of heat generated by the illuminator is severely reduced from a traditional tungsten filament light.

Focal Distance
The distance between the end of an objective and the surface of the specimen.

Focal Point
In microscopes, as magnification increases the focal distance decreases.

Halogen
Microscopes with halogen lamps emit more intense white light, but also emit a considerable high heat which can quickly destroy living specimens.

Immersion Oil
A special oil used with an 100x objective to increase resolution and concentrate the light on the slide. A drop of oil must be placed on the cover slip and the 100x objective must touch the oil.

Incident Light
Any light that falls on the specimen or slide on the microscope.

Infinity
The objective lenses are designed to project their images to infinity, not to some finite distance. It provides an “infinite” region of parallel light between objective and eyepiece.

Infinity Achromatic
A quality flat field of focus for 60% of the field of view projecting the image to infinity.

Infinity Plan
The highest quality flat field of focus for 100% of the field of view projecting the image to infinity. Parts of the specimen at the edge of the field of view are as well-focused as the center part of the specimen.

Infinity Semi-Plan
A high quality flat field of focus for 80% of the field of view projecting the image to infinity.

Interpupillary Distance
The distance between the two eyepieces, usually adjustable, on a binocular microscope to fit the user.

Iris
Adjusts the brightness of the image

Iris Diaphragm
A device consisting of thin, overlapping metal plates that can be adjusted to form an opening (aperture) of varying diameter regulating the amount of light entering the microscope.

Kohler Illumination
Uses a field diaphragm and an aperture iris diaphragm to control illumination. This allows the user to look at a specimen at high magnification without glare and minimum heating of the specimen.

Light Emitting Diode (LED)
A light source that does not generate significant heat, nor destroy living specimens.

Light Rheostat
A device which allows for adjustment of light intensity on a microscope, similar to a room dimmer switch.

Magnification
In microscopes, to make something larger in size by use of lenses. Total magnification is determined by multiplying the magnification of the eyepiece lens by that of the objective lens. (For example, eyepiece 10x and objective 40x= 400 times magnification.)

Mechanical Stage
A specialized mechanism, into which a slide may be inserted and moved around with great precision in very small increments. Most mechanical stages have both an ‘X’ and a ‘Y’ Vernier axis, allowing exact marking of location of an object on a microscopic slide.

Monocular Head
A microscope with a single eye tube, set at 45o to the head for viewing by one observer at a time.

NiMH (Nickel Metal Hydride) Battery
For cordless microscopes, the NiMH battery can have two to three times the capacity of an equivalent size NiCd (nickel cadmium) battery.

Nosepiece
The upper part that holds the objective lens in a compound microscope, sometimes referred to as a turret.

Numerical Aperture
The measure of the diameter of the aperture (opening) compared to the focal length of the lens and it indicates the resolving power of a lens. A lens with a larger numerical aperture will be able to visualize finer details than a lens with a smaller numerical aperture.

Objective Lens
The lens closest to the specimen that first receives light emitted by the light source and forms an image in the focal plane of the eyepiece. Objective lenses are designed to maximize the ultimate resolution of the microscope.

Oil Immersion Lens
An 100x or higher objective lens designed to work with a drop of immersion oil.

Parcentered
The image of the specimen stays centered when moving to the next objective lens.

Parfocal
The image of the specimen stays in focus when moving to the next objective lens.

Phase Contrast
A technique that shifts the light phase wavelength, thus causing the light deviated by the specimen to appear dark on a light background.

Plan Objective
A lens that is corrected for flatness of field, so when in focus the entire image is greatly enhanced and 100% of the field of view is in focus.

Rack and Pinion
Refers to the interlocking of a series of gears and cams that allows the coarse and fine adjustment knobs to interact.

Resolution
The ability of the lens to show the fine details of the specimen.

Seidentopf Binocular Head
Two eyepieces, with the 360° rotating head designed so that by increasing or decreasing the distance between the two eyepieces (interpupillary distance) is done by twisting the eyepieces in an up and down arc motion similar to most binoculars.

Semi-Plan Objective
A lens that is partially corrected for flatness of field, so when in focus the entire image is improved.

Singlet Control
One knob does both coarse and fine adjustment.

Stage Clips
Clips attach the slide to the stage.

Stereo Microscope
See Dissecting Microscope

Transmitted Light
Light emitted from the illuminator (light source) and passing through the slide or specimen to the objective lens.

Trinocular Head
A microscope that has a binocular head for viewing and an additional eyepiece for a camera mount.

Tucked Reverse Head
In a compound microscope, the objectives are placed such that they are positioned back towards the arm of the microscope allowing for ease of inserting or removing slides from the stage.

Tungsten
A light that gives intense, white light, but also emits considerable heat which can quickly kill living specimens.

Universal Serial Bus (USB) Adapter
An accessory allowing the conversion of an analog signal to a digital signal.

Universal Serial Bus (USB) Controller
A standard connection to interface devices such as a microscope and camera to a computer, projector, interactive white board, etc.

Vernier Scale
A small moveable, calibrated scale that slides along a main scale to indicate fractional differences.

Vertical Binocular Head
The binocular lens is placed vertically, directly above the objective lens.

Wide Field Eyepiece
An eyepiece with an achromatic doublet lens which allows the observer to view through the whole lens diameter rather than being limited to viewing only in the center of the field.

x/y Floating Stage
Allows movement of the stage along the X and Y axes, but not Z, so therefore not 360°.