Blob Analysis

The purpose of a blob tool (sometimes called a connectivity tool) is to measure the parameters of discrete objects within an image.

GigE

See: GigE Vision

GigE Vision (Gigabit Ethernet for Machine Vision) is an interface standard for high-performance Machine Vision cameras.

OCR

OCR (Optical Character Recognition) is a special case of pattern recognition.

Glossary (Optics)

Aberration

See: Spherical Aberration

The images produced from a spherical lens will be subject to increasing amounts of blur towards the edges.

Aperture

See: F-number (F-stop)

The F-number, also known as F-stop or numerical aperture, defines the amount of light that can pass through any lens setup.

Aspherical Lens

Lens group comprising aspherical lenses

Back Focal Distance

The back focal distance is the mechanical distance between the mating surface of a lens on the housing of a camera and the camera sensor.

C-Mount

A very common standard in image processing for connecting a lens to a camera with a one-inch thread

Chromatic Aberration

Chromatic abberation is caused by the fact that colours have different focal points.

Coating

Anti-reflection method used for the surfaces of optical components

Cos4 Vignetting

All lenses can potentially suffer from what is called Cos4 vignetting, when the light entering from the extremities of the image strikes the sensor at a shallow angle.

Cover

See: Coating

Anti-reflection method used for the surfaces of optical components

CS-Mount

A common standard in video security monitoring for connecting a lens to a camera with a one-inch thread

CS-Mount Adapter

Spacer ring with a thickness of 5 mm.

Depth of Focus

Region in which the image of an object appears to be sharp in the direction of the optical axis.

Dichroic Filters

The term 'dichroism' derives from the Greek and in physics refers to the splitting of visible light into two colours when passing through crystals.

F-Mount

A lens connector used in image processing particularly for high-resolution cameras or line scan cameras.

F-number (F-stop)

The F-number, also known as F-stop or numerical aperture, defines the amount of light that can pass through any lens setup.

Filters

See: Dichroic Filters

The term 'dichroism' derives from the Greek and in physics refers to the splitting of visible light into two colours when passing through crystals.

Focal Distance

See: Minimum Focus Distance

Least possible distance from an object at which a lens can still be focused with no auxiliary equipment.

Focal length

The focal length of a lens is the distance between its effective centre and the point at which light from infinity will be focused to a single point.

Focal Setting

See: Focusing

Focusing of a lens.

Focusing

Focusing of a lens.

Iris (Aperture)

See: F-number (F-stop)

The F-number, also known as F-stop or numerical aperture, defines the amount of light that can pass through any lens setup.

Lens Filters

Filters can dramatically alter the character of the light that enters a lens and they can have a wide variety of uses, from simple protection of the lens surface to restricting certain wavelengths ...

Lens Types

Virtually all cameras need a lens of some kind to collect the light that is scattered from the surface of an object.

Macro Lenses

Macro lenses are specifically designed for small fields of view (FOV), which are approximately equal to the camera's sensor size.

MC

See: Coating

Anti-reflection method used for the surfaces of optical components

Mechanical Vignetting

This is governed by the maximum image circle that a lens can produce and is caused by clipping in the optical train.

Minimum Focal Distance

See: Minimum Focus Distance

Least possible distance from an object at which a lens can still be focused with no auxiliary equipment.

Modulation Transfer Function (MTF)

MTF refers to the ability of a lens to accurately reproduce an image of alternating black and white lines with a known spacing onto an image plane.

Multi Coating

See: Coating

Anti-reflection method used for the surfaces of optical components

Multi Layer Coating

See: Coating

Anti-reflection method used for the surfaces of optical components

Nikon Bajonet Mount

See: F-Mount

A lens connector used in image processing particularly for high-resolution cameras or line scan cameras.

Sensor Shading

Any image created using a lens and sensor arrangements will suffer from a non-uniform distribution of intensity, because even if the entire field of view has an even light distribution, the ...

Shading

See: Sensor Shading

Any image created using a lens and sensor arrangements will suffer from a non-uniform distribution of intensity, because even if the entire field of view has an even light distribution, the ...

Shading

See: Sensor Shading

Any image created using a lens and sensor arrangements will suffer from a non-uniform distribution of intensity, because even if the entire field of view has an even light distribution, the ...

Sharpness

See: Focusing

Focusing of a lens.

Spatial Distortion

In an ideal scenario, the image created by any lens would be an exact representation of the object in the field of view. Unfortunately all lenses suffer from distortion, to different degrees.

Spectral Transmission

Different optical materials transmit the many wavelengths of light with differing efficiencies, and all wavelengths are reflected or absorbed in varying amounts.

Spherical Aberration

The images produced from a spherical lens will be subject to increasing amounts of blur towards the edges.

Telecentric Lenses

Telecentric lenses are designed specifically for use in specialist measurement applications where per-spective projections and incorrect image scaling can cause problems.

Vignetting

All images from lenses suffer from intensity variation from the centre to the edge of the image. As this can affect the suitability of a lens for an application, it is often necessary to examine ...

Working Distance

The working distance is the distance between object and lens front edge.

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