Ghost Image

Ghost image (optics)

An undesired image appearing at the image plane of an optical system. Each surface of an optical system divides the incoming light into two parts: (1) the reflected light, which returns into the first medium, and (2) the refracted light. The reflected light is again divided into two parts when it in turn strikes another dividing surface. The light thus reflected twice forms an image which may be near the plane of the primary image. This may be a false image of the object or an out-of-focus image of a bright source of light in the field of the optical system. Thus a large number of undesired or ghost images may appear. See Optical image, Reflection of electromagnetic radiation, Refraction of waves

If the ghost images are far out of focus, they only diminish the contrast in the primary image, a condition known as flare. But if the ghost images are near the focal plane, they are very disturbing. This effect is especially noticeable if there is a bright light source in the field of the instrument, since the ghost image of the light source may have an even greater brightness than the image of the desired object. The coating of lenses with layers of fluorite and other materials has nearly eliminated ghost images from modern optical systems.

McGraw-Hill Concise Encyclopedia of Physics. © 2002 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Ghost Image


a secondary image that appears in the image plane of an optical system because of the reflection of light from the surfaces of components such as lenses, prisms, and plates. The chief cause of ghost images in lens systems is the multiple reflection of light from the lens surfaces. If brightly illuminated portions of the object being viewed border on sharply delineated shadows, the appearance of ghost images from such portions in the shaded parts of the primary image may noticeably distort the image of the object. Ghost images can be controlled by the use of antireflection coatings on the surfaces of the optical components.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

ghost image

[′gōst ‚im·ij]
An undesired duplicate image near the desired image on a television receiver or computer display screen.
An undesired image appearing at the image plane of an optical system; it may be a false image of the object or an out-of-focus image of a bright source of light in the field of the optical system.
A false image of a spectral line produced by irregularities in the ruling of a diffraction grating.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

ghosting server

A server that contains a group of programs to be duplicated verbatim onto other PCs. It typically contains the operating system and a selected set of applications that are preconfigured. See cloning software.
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References in periodicals archive ?
The ghost image feature appears like a floating image in one colour under or beneath the main object image, and moves on tilting or when the illumination position changes.
The ghost image is powder used in the manufacturing process to keep the inner walls of the balloon from sticking together before inflation.
It is well known that vibrating targets cannot be focused in microwave SAR images and a ghost image will generally result according to the paired echo principle.
It is when the figure's head comes rapidly into close-up that Alice captures what seems to be an image of herself or, at least, a ghost image or death image of herself.
In addition to the existing Postal Reference Number (PRN), guilloche and Quick Response (QR) code, the security features on the improved postal ID include: a hologram of a running mailman seen only at a certain angle; ultraviolet (UV) ink that lights up under UV light; and a smaller ghost image of the cardholder's photo.
In the ' censored' photograph, a ghost image of a white cutout of Lalu appears alongside the photographs of Tejashwi and Gadkari.
I had to stop myself from turning to his ghost image to my right, as I visualised him grinning hugely.
"The data chip and ghost image embedded in the passport make it nearly impossible to tamper with a passport, and replicate it for identity theft," said the official.
After opening with a shot of the filmmaker's mother in a hospital bed (upon which has been superimposed a ghost image of snow billowing into the lens), "Broken Record" actually opens in Iceland.
Yeah, kinda like a ghost image, like what our mind thinks a sound is supposed to look like.
One big difference with a touchscreen tablet over a pointer or mouse on a laptop or PC is that there's no "mouse-over" capability with a tablet, whereas a pointer on a laptop or a mouse on a desktop can hover over something on a web page to make a ghost image appear with more detailed information.
Firstly, trigger MY9268 Automatic Black Frame Insertion and within adjustable period, pull output pin to high voltage, therefore ghost image will be abated.