Fazendo 3D com uma camera so
A simple system to make stereo photography or videos based in just two mirrors was made in 1989 and recently adapted to a digital camera setup.
physics.pop-ph↗
arXiv subjects
J. J. Lunazzi
Publications and source records attributed to J. J. Lunazzi.
Estereoscopio com tela holografica para ver tomografias
A estereoscopia eh uma tecnica que permite a observacao de imagens tridimensionais, mas estah sempre associada com o uso de algum equipamento especial para visualizacao, como oculos bicolores ou polarizados. Para o uso em aplicacoes medicas o emprego de tais equipamentos pode inviabilizar sua utilizacao durante procedimentos cirurgicos, por exemplo. Neste trabalho apresentamos um novo tipo de estereoscopio que utiliza uma tela holografica para geracao de imagens tridimensionais sem o uso de qualquer equipamento adicional. Apresentamos a descricao do equipamento utilizado e resultados das imagens visualizadas.
physics.optics↗
La Nube: La Manera Mas Emocionante De Experimentar Espejos Planos
ESPANOL: Una experiencia que parte del uso de un espejo plano colocado horizontalmente a la altura de la nariz del observador, que permite uma nueva dimension a la experiencia de ver imagenes com espejos simples, sirve para discutir lo que aun puede hacerse para que el estudiante gane uma vision mas profunda y conceptual en el aprendizaje de la fisica. El enfasis esta en la idea de independencia mental, que incluye la de que nuevos resultados pueden surgir en el analisis de experimentos que no necesariamente precisan ser hechos con elementos nuevos o de sofisticada realizacion. ENGLISH TRANSLATION: The experience of employing a plane mirror located at the height of the nose of an observer, giving a new dimension to the experiences made with simple mirrors, is used as an example into the discussion of what can be done for the student to reach a deeper and conceptual insight in learning Physics. The main idea lays on the mental independence, which includes that new results can come through the analysis of experiments which not necessarily needs to be made with new elements or through a sophisticated procedure.
physics.ed-ph↗
Enlarging Holograms Under White Light, a Way to Save Holographic Material
We developed techniques for employing holographic screens under white light, first exhibited to the public in 1989 (3) (4) which demonstrated the possibility of enlarging holograms already in 1990 (5). Fig. 1 shows how we encode views in a first step. The plane of the figure is horizontal, and a thin vertical slit is necessary to project each different view of the scene at a different sequential wavelength value. Decoding happens because the projected views are naturally angularly redistributed by the holographic screen (6).
physics.optics↗
White Light Colour Photography for Rendering Holoimages in a Diffractive Screen
The capability of color encoding the continuous sequence of views from a scene was demonstrated previously by the author (1990). In the present work, the scheme for this process is shown where white light from a black and white object is diffracted at a diffraction grating and then photographed on colour film. Two rays of different wavelengths reaching the plane of the color photographic film determine the stereo representation of an object point. Since the wavelength may have any value within the continuous visible spectrum, this case constitutes a new situation of continuous stereo photography. A natural process of decoding is represented where a diffusing white light source was added from the side of the developed photographic film. One white light ray that matches the former position of an incident ray receives the spectral characteristics of the registered point when traversing the photographic slide. It characterizes a situation of light path reversal, and the ideal result corresponds to a projected white light point being focused at the original object position. This situation generates a pseudoscopic image of the object, as seen from a certain distance, whose colour depends on the horizontal position of the observer.
physics.optics↗
Holo-Television System with a Single Plane
We show a system capable of projecting a video scene on a white-light holographic screen to obtain a kind of image that results in a plane in front of the screen. This holographic screen is mainly a diffractive lens and it is constructed by holography. The image plane can be located at any azimuth angle and seen with continuous parallax and without the use of goggles or any special visualization equipment. The image is not volumetric but when the plane is oblique to the observer its appearance looks very close to a real volumetric image.
physics.optics↗
Photographing by means of a diffractive axicon
In this paper we demonstrate that the light diffracted by a simple compact disc can be used to generate photographic images of a certain kind. Being the compact disc an axicon that generates a diffraction-free beam, we show that the focusing position of an image depends of the wavelength of the diffracted light, what makes possible its use as a spectral filter.
physics.ed-ph↗
Holophotography with a diffraction grating
Color encoding of depth is shown to occur naturally in images of objects observed through diffraction gratings under common white light illumination. A synthetic image is then obtained from a single point of view, a phenomenon that can be applied to stereophotography. The image can be recorded in a common color photograph, providing a simple method of visual decoding by means of ordinary colored 3D spectacles. The fundamental equation and the photographic procedure for maximum fidelity in three-dimensional reproduction are described. The result is a photograph that has the capability of registering all the views of an object in a continuous sequence, which is called holophotography and was previously obtained by means of a hologram. By eliminating the need for a laser and holographic film, a new technique for holography in white light is foreseen.
physics.optics↗
Three-dimensional photography by holography
Color encoding of depth is shown to occur naturally in holograms that are reconstructed under white light illumination. It can be registered in a common color photograph, allowing a simple method of visual decoding by means of ordinary colored 3-D spectacles. The fundamental holographic equations and the photographic procedure required for maximum fidelity in three-dimensional reproduction are described. The result is a new kind of photograph that shows all of the views of the object in a continuous sequence. It permits an animated photographic representation and also makes it possible to adjust the degree of depth visualization when observed as a stereoscopic representation.
physics.optics↗
Optica Precolombina Del Peru
Archaeological American mirrors are common findings and the images obtained with them are often described by archaeologists as possessing high quality. However, photographs attesting this fact are rare, if any. To the best of my knowledge, only two papers show that quality concerning the Olmeca culture, and only one of them mentions the pre-Inca cultures case. Certainly more images are needed to increase awareness of the importance of the existence of sophisticated imaging elements, particularly when evaluating the cultural degree of the pre-Columbian civilizations. In this paper we show images made in two museums in Lima, Peru, by means of mirrors and the lens action on a necklace element.
physics.pop-ph↗
Olmec mirrors: an example of archaeological American mirrors
Archaeological mirrors from the Olmec civilization are described according to bibliographic references and to personal observations and photographs.
physics.pop-ph↗
On the quality of the Olmec mirrors and its utilization
Archaeological mirrors from the Olmec civilization were analyzed in the context of bibliography produced in the last two decades. Photographs of its images are showed as a proof of its good quality. Some suggestions are made on its probable utilization.
physics.pop-ph↗
The use of diffractive screens for electronic imaging
Diffractive screens are high-resolution elements with capability for generating holographic-like images from a sequence of planes where TV frames are seen oblique to it. If we project a sequence of contour lines of an object it could be seen in continuous horizontal parallax to a size of 1m3.
physics.optics↗
Lensless Slide Projection: A Demonstrative Experience
A 2D transparency may be projected on a diffractive screen by just illuminating it with a filament lamp of the same height. Sharpness of the filament width is naturally related to sharpness on the image, but some peculiar properties makes this experience to be different from a shadow projection case.
physics.optics↗
Holoprojection of Images by a Double Diffraction Process
Three dimensional images having continuous horizontal parallax were developed by wavelength enconding of view followed by a natural decoding process of projection onto a diffractive screen. It allows for the direct criation of "holoimages" by using projected images of a real object substituting holographic images for some applications in the visual aarts. It also allows for the enlargement of holograms performing simultaneously its conversion to the white light observation. White light is employed in this process, since laser light is only necessary for constructing the diffractive components.
physics.optics↗