The main difference between Hologram and Iridescent is that the hologram is a photographic recording of a light field, rather than of an image formed by a lens, and it is used to display a fully three-dimensional image of the holographed subject and Iridescent is a property in which fine colors, changeable with the angle of view or angle of illumination, are produced on a surface by the interference of light that is reflected from both the front and back of a thin film.
Holography is the science and practice of making holograms. Typically, a hologram is a photographic recording of a light field, rather than of an image formed by a lens, and it is used to display a fully three-dimensional image of the holographed subject, which is seen without the aid of special glasses or other intermediate optics. The hologram itself is not an image and it is usually unintelligible when viewed under diffuse ambient light. It is an encoding of the light field as an interference pattern of seemingly random variations in the opacity, density, or surface profile of the photographic medium. When suitably lit, the interference pattern diffracts the light into a reproduction of the original light field and the objects that were in it appear to still be there, exhibiting visual depth cues such as parallax and perspective that change realistically with any change in the relative position of the observer. In its pure form, holography requires the use of laser light for illuminating the subject and for viewing the finished hologram. In a side-by-side comparison under optimal conditions, a holographic image is visually indistinguishable from the actual subject, if the hologram and the subject are lit just as they were at the time of recording. A microscopic level of detail throughout the recorded volume of space can be reproduced. In common practice, however, major image quality compromises are made to eliminate the need for laser illumination when viewing the hologram, and sometimes, to the extent possible, also when making it. Holographic portraiture often resorts to a non-holographic intermediate imaging procedure, to avoid the hazardous high-powered pulsed lasers otherwise needed to optically "freeze" living subjects as perfectly as the extremely motion-intolerant holographic recording process requires. Holograms can now also be entirely computer-generated to show objects or scenes that never existed. Holography is distinct from lenticular and other earlier autostereoscopic 3D display technologies, which can produce superficially similar results but are based on conventional lens imaging. Stage illusions such as Pepper's Ghost and other unusual, baffling, or seemingly magical images are also often incorrectly called holograms.
Iridescence (also known as goniochromism) is the phenomenon of certain surfaces that appear to gradually change colour as the angle of view or the angle of illumination changes. Examples of iridescence include soap bubbles, butterfly wings and seashells, as well as certain minerals. It is often created by structural coloration (microstructures that interfere with light). Pearlescence is a related effect where some or all of the reflected light is white, where iridescent effects produce only other colours. The term pearlescent is used to describe certain paint finishes, usually in the automotive industry, which actually produce iridescent effects.
A three-dimensional image of an object created by holography.
Producing a display of lustrous, rainbow-like colors; prismatic.
Brilliant, lustrous, or colorful.
a three-dimensional image formed by the interference of light beams from a laser or other coherent light source.
a photograph of an interference pattern which, when suitably illuminated, produces a three-dimensional image.
A photographic image giving the observer a seemingly three-dimensional view of the represented object. The three-dimensional effect is produced by exposing a photographic recording medium to an interference pattern generated by a coherent beam of light (as from a laser) reflected from the subject, interacting with a beam directly from the source. The full three-dimensional effect requires illumination of the image with coherent light, but less perfect three-dimensional visual effects may also be observed when the hologram is illuminated with white light.
Having colors like the rainbow; exhibiting a play of changeable colors; nacreous; prismatic; as, iridescent glass. See iridescence.
the intermediate photograph (or photographic record) that contains information for reproducing a three-dimensional image by holography
varying in color when seen in different lights or from different angles;
"chatoyant (or shot) silk"
"a dragonfly hovered, vibrating and iridescent"
having a play of lustrous rainbow-like colors;
"an iridescent oil slick"
"nacreous (or pearlescent) clouds looking like mother-of-pearl"
"a milky opalescent (or opaline) luster"