Showing papers in "The Imaging Science Journal in 1969"
TL;DR: A method of determining the time resolution of an Image Converter Camera using laser radiation is described and records indicate that time intervals of the order of 3.1O-12sec are resolvable.
Abstract: A method of determining the time resolution of an Image Converter Camera using laser radiation is described. Records indicate that time intervals of the order of 3.1O-12sec are resolvable.
40 citations
TL;DR: In this paper, the average size of latent image speck required for developability, and the average number of absorbed quanta required to form a developable speck are independent of grain size, and it follows that speed should increase indefinitely with grain size.
Abstract: On the assumption that the average size of latent-image speck required for developability, and the average number of absorbed quanta required to form a developable speck, are independent of grain size, it follows that speed should increase indefinitely with grain size.Speed/grain-size relationships for experimental series of emulsions have been derived and compared with theoretical trends. These comparisons show that the number of quanta per grain required for developability steadily increases with size within the normal size range. In one series this led to an optimum and then a decrease of speed despite increasing grain size.On exposure of emulsions to X-rays of such energy as to render one grain developable for each quantum absorbed, speed increases up to the largest grain size. In this case the number of electrons released by an X-ray quantum is such that large inefficiencies in formation of a developable latent-image speck can be tolerated. Excellent agreement between theoretical and experime...
16 citations
TL;DR: In this article, a review of halide layer photography is given, in the light of recent experiments on the sensitivity, resolution, contrast and stability of the halide layers, as well as their applications in image recording, holography and information storage.
Abstract: Thin layers of many halides and chalcogenides can be used for image recording since they decompose when illuminated, at a suitable temperature, with light that is absorbed in their fundamental absorption region. A review is given of this process and of the range of materials now available for ‘halide layer photography’. Potential applications of halide layers in image recording, holography and information storage are discussed in the light of recent experiments on the sensitivity, resolution, contrast and stability of the layers.
16 citations
TL;DR: The tone reproduction of colour photographic systems typical of those used for producing reflection prints and reversal transparencies for amateurs has been measured, both by the usual sensitometric methods, and by the telephotometry of images seen in typical viewing situations.
Abstract: The tone reproduction of colour photographic systems typical of those used for producing reflection prints and reversal transparencies for amateurs has been measured, both by the usual sensitometric methods, and by the telephotometry of images seen in typical viewing situations. It was found that the high slopes of the sensitometric characteristic curves of these systems were reduced by camera, printer, and viewing flare, especially the latter. The overall log luminance transfer characteristic, as measured by telephotometry, was found to have a slope, in the middle part of the scale, of about 1.5 for projected transparencies and 1.0 for reflection prints: these values are in close agreement with those found in other investigations, in which subjective brightness scaling was used.
14 citations
TL;DR: In this paper, a good understanding of the absorption curves for yellow, green, and neutral silver was obtained by applying the Mie and Cans theories to the sizes and shapes of silver particles which were observed in electron micrographs of microtomed sections of processed emulsions.
Abstract: When fine-grain photographic emulsions were developed, separated spheres or ellipsoids of silver were produced. The colour and covering power of the silver depended sensitively upon the sizes and shapes of the particles. A good understanding of the absorption curves for yellow, green, and neutral silver was obtained by applying the Mie and Cans theories to the sizes and shapes of silver particles which were observed in electron micrographs of microtomed sections of processed emulsions. A covering power limit of 360 for neutral silver was obtained experimentally and verified theoretically. Much higher values were obtained for coloured specimens. Covering power as high as 1850 was measured for silver spheres suspended in water. Detailed comparison of experimental and theoretical values of absorption for silver spheres showed sufficient discrepancy to require different optical constants for silver in bulk and in small particles. Additional changes in the optical constants of silver particles were obs...
12 citations
TL;DR: In order to clarify the nature of the interaction of the dye with silver halides, the adsorption of 2,2'-quinocyanine to silver chloride, bromide and iodide has been studied from various viewpoints as discussed by the authors.
Abstract: In order to clarify the nature of the interaction of the dye with silver halides, the adsorption of chloride, bromide and iodide of 2,2’-quinocyanine to silver chloride, bromide and iodide has been studied from various viewpoints. Adsorption isotherms, values of heat of the adsorption and of the saturation maximum of the adsorbed dyes. X-ray diffraction of dyed silver halides, and IR and visible absorption spectra of the adsorbed dyes have indicated that the dye interacts with the surface of silver halides by van der Waals’ forces and electrostatic ones.
10 citations
TL;DR: In this article, the influence of development on equivalent quantum efficiency was investigated and it was concluded that in general detection can be improved by using slightly shorter development times than are customary for more conventional purposes.
Abstract: When the photographic process is used at the limits of detection, as in many scientific applications, it is important to optimize the signal-to-noise ratio of the photographic image. This may involve using exposing and processing techniques other than those which are customary for more general conditions of use.The results presented here are concerned with the influence of development on equivalent quantum efficiency. It is concluded that in general detection can be improved by using slightly shorter development times than are customary for more conventional purposes.
5 citations
TL;DR: In this paper, the experimental noise spectra of experimental emulsions with homogeneous cubic grains are compared with the theoretical noise spectrum of an ideal emulsion, which has a greater range of grain sizes.
Abstract: In this paper, the Wiener spectra of experimental emulsions with homogeneous cubic grains are compared with the Wiener spectra of commercial emulsions which have the same mean radius as the experimental emulsions but have a greater range of grain sizes. The experimental noise spectra are then compared with the theoretical noise spectrum of an ideal emulsion.
4 citations
TL;DR: In this article, the inefficiency of 5-methyl-7-hydroxy-1, 3, 4-triazaindolizine (Aza) os an antifoggant in a developer is caused by the desorption of Aza from the development centres by developing agents and bromide and is also influenced by the sulphite concentration and the pH of the bath.
Abstract: The inefficiency of 5-methyl-7-hydroxy-1, 3, 4-triazaindolizine (Aza) os an antifoggant in a developer is caused by the desorption of Aza from the development centres by developing agents and bromide and is also influenced by the sulphite concentration and the pH of the bath. Nitrobenzimidazole (Nitro) is not desorbed completely under the same conditions. The adsorption on the specks measured with C14-labelled Aza, Nitro and benzimidazole, is not only influenced by the solubility product of the silver salts but also by other factors such as gelatin concentration and by the value of the acid dissociation constant. So with increasing pH the adsorption of Aza on the active centres diminishes and the adsorption of Nitro increases. In addition the Aza is in competition with the gelatin for the adsorption on the grains. The adsorption of Aza on the grains reduces the amount of adsorbed gelatin and this may cause the increase in sensitivity by Aza. Our results indicate on adsorption of hydroquinone on th...
4 citations
TL;DR: In this article, a review of halide layer photography is given, in the light of recent experiments on the sensitivity, resolution, contrast and stability of the halide layers, as well as their applications in image recording, holography and information storage.
Abstract: Thin layers of many halides and chalcogenides can be used for image recording since they decompose when illuminated, at a suitable temperature, with light that is absorbed in their fundamental absorption region. A review is given of this process and of the range of materials now available for ‘halide layer photography’. Potential applications of halide layers in image recording, holography and information storage are discussed in the light of recent experiments on the sensitivity, resolution, contrast and stability of the layers.
3 citations
TL;DR: In this article, the authors investigated the characteristics of an a.c.w. arc in SF6 and developed an optical technique in which the monochromatic light from a 4 watt c.p.s. laser enables the physical dimensions of the arc and the gas flow in and around it to be photographed at up to 107 p.m.
Abstract: An investigation into characteristics of an a.c. arc in SF6 has led to the development of an optical technique in which the monochromatic light from a 4 watt c.w. laser enables the physical dimensions of the arc and the gas flow in and around it to be photographed at up to 107 p.p.s. To date, using an adapted schlieren system, results have been obtained in nitrogen at 6 & 103 p.p.s. In the immediate future the equipment will be modified to use SF6, and an Image Converter camera used to attain 107 p.p.s. Characteristics of the laser are discussed, including observations made using argon and krypton.
TL;DR: In this paper, the results of tests made on Kodak AR.10 stripping film in this laboratory are presented, and the film was tested for optimum development time and temperature, latent image fading and accumulation of image and the effect of the exposure temperature on the latent image.
Abstract: Results of tests in various laboratories on photographic emulsions used in autoradiography are compared, and attention is drawn to the differences reported. The results of tests made on Kodak AR.10 stripping film in this laboratory are presented. The film was tested for optimum development time and temperature, latent image fading and accumulation of image and the effect of the exposure temperature on the latent image. When exposed at -23°C, latent image fading does not prevent accumulation of the image for exposures of up to 200 days.
TL;DR: In this paper, the effect of the statistical distribution of the size of the elements is investigated and the relationship between the spatial distribution of individual sensitive elements and the image characteristics of the detector is discussed.
Abstract: Previous theoretical studies1,2 have concerned the relationship between the spatial distribution of the individual sensitive elements and the image characteristics of the detector. The influence of the statistical distribution of the quantum sensitivity of the elements has also been considered. In the present report the effect of the statistical distribution of the size of the elements is investigated.
TL;DR: In this paper, the subject matter of exposure and line definition, chemical resistance, viscosity, pinhole densities and variations in Photoresist thickness are discussed. But the authors focus on the subject of exposure, line definition and line width.
Abstract: Since the advent of Microimage Transistor Geometries, requiring oxide cuts in the region of one to five microns, precise specifications and easier methods of detecting process failure in the Photoresist Technology have become increasingly necessary to meet the high yield requirements of these devices. This investigation looks at the Microimaging properties of K.T.F.R. Photoresist and its associated electronic grade solvents and discusses the subject matter of exposure and line definition, chemical resistance, viscosity, pinhole densities and variations in Photoresist thickness, with all the processes and measurements being carried out on standard laboratory equipment.
TL;DR: The first system to reproduce images photomechanically was heliogravure, introduced in 1826 by Joseph Nicephore Niepce of France as discussed by the authors, which was followed 13 years later by attempts by various experimenters to chemically etch daguerreotypes.
Abstract: The first system to reproduce images photomechanically was heliogravure, introduced in 1826 by Joseph Nicephore Niepce of France. This was followed 13 years later with attempts by various experimenters to chemically etch daguerreotypes. Neither approach proved wholly satisfactory. In1852and1858 William Henry Fox Talbot of England patented the first practicable photomechanical systems. These techniques were capable of converting continuous-tone images into ink images on paper using methods which established the foundation of photogravure as we know it today. Talbot’s approaches relied heavily upon the positive photographic print, a feature which was part of the photographic negative-positive system introduced by him in 1839. Talbot’s photomechanical innovations consisted of the bichromated gelatin emulsion; contact screens; photoaquatint; etching a metal plate through the light-exposed, selectively hardened emulsion; use of a relatively “safe” etchant; using etchants of different concentrations to ...
TL;DR: In this article, a study of the entrapmention of a sphere on a flat surface which is covered by a fluid film is described, under certain conditions, a pool of fluid becomes entrapped in the contact region.
Abstract: When a sphere approaches a flat surface which is covered by a fluid film, under certain conditions, a pool of fluid becomes entrapped in the contact region. A study of this phenomena is described in which optical interference is used. High speed photography is employed at framing rates up to 5,000 per second, with a gas laser as the light source.
TL;DR: In this paper, surface potential and surface conductivity in zinc oxide thin films in contact with eosin dye were measured under vacuum conditions, and two regimes of spectral sensitization were involved.
Abstract: Measurements of surface potential and surface conductivity in zinc oxide thin films in contact with eosin dye show that two regimes of spectral sensitization are involved under vacuum conditions. The dye molecules at the interface trap conduction electrons in the dark at a site close in energy to the dye ground state leading to a Schottky barrier. The return of the trapped electrons from the excited dye is held responsible for “thin layer” sensitization. With “thick” dye layers an additional contribution arises from charge transfer between the photoconducting solid dye and the zinc oxide substrate, in a direction which tends to equilibrate the Fermi levels in the two media, The decay of the ”thick layer” sensitized photoeffect is identical to the decay of the field effect in undyed zinc oxide films and is controlled by zinc oxide surface states.
TL;DR: The first practicable photomechanical system, contact-screen photogravure, was invented in 1852 by W. H. F. Talbot as mentioned in this paper, who used fine gauze fabrics for the contact cross-line screens and fine resin particles (aquatint) applied as a powder or liquid.
Abstract: The first practicable photomechanical system—contact-screen photogravure—was invented in 1852 by W. H. F. Talbot of England. Many of the approaches introduced by Talbot are still used in current practice: contact cross-line “master” and “working” screens: metal plate etching through a bichromated gelatin emulsion: etching with ferric chloride solutions of different concentrations: and selective local etching for “retouching” purposes.To provide the tiny image ink-holding components in the printing plate, Talbot used fine gauze fabrics for the contact cross-line screens and fine resin particles (aquatint) applied as a powder or liquid. He also experimented with contact screens of ruled lines on paper: scored cartilage: waxed paper with scribed lines: aquatint pattern on paper and a blackened film with uniform grid of clear circular openings.
TL;DR: In this article, a geometrical description of holographic image aberrations is developed, and the problem of obtaining extended images with controlled resolution at the range of 2λ could be solved if geometry repetition and emulsion conservation are provided.
Abstract: A new approach to geometrical description of holographic image aberrations is developed. It is shown that the problem of obtaining extended images with controlled resolution at the range of 2λ could be solved if geometry repetition and emulsion conservation are provided.
TL;DR: In this article, the use of image motion in the simulation of images with precisely known imaging characteristics is discussed from the viewpoint of the effective sine-wave response used in the image formation.
Abstract: The use of image motion in the simulation of images with precisely known imaging characteristics is important in such investigations as image evaluation and psychophysical studies. Image motion spread functions generated by double-exposures, where each exposure is of the same duration but the image velocity differs, are discussed from the viewpoint of the effective sine-wave response used in the image formation. It is shown that various combinations of exposure may be used to produce effective sine-wave response functions of differing shapes. Experimental confirmation of the utility of image-motion to produce controlled imaging characteristics is given by a comparison of measured and theoretically derived effective square-wave responses.
TL;DR: The processing of silver halide materials is reviewed from three standpoints: silver, water and colloid binders, to indicate some of the limiting factors as mentioned in this paper, and the results are shown in Table 1.
Abstract: The processing of silver halide materials is reviewed from three standpoints:—silver, water and colloid binders, to indicate some of the limiting factors.
TL;DR: In this paper, the influence of definite amounts of gelatin on sensitometry, rate of development and rate of fixation was studied. But the effect of gelatin was not unique, as binding agents such as casein, polyvinylpyrrolidone or polyvinYLalcohol behave qualitatively identically.
Abstract: Binder-free silver bromide suspensions were used to study the influence of definite amounts of gelatin on sensitometry, rate of development and rate of fixation. Development and fixation are strongly retarded by gelatin. The retardation increases linearly with the gelatin concentration until the surface of the silver halide is covered by a close- packed monolayer. Higher concentrations have little supplementary effect. Gelatin increases the selectivity of development and gives rise to filamentous silver. In this sense however it is not unique, as binding agents such as casein, polyvinylpyrrolidone or polyvinylalcohol behave qualitatively Identically. High-isoelectric-point gelatins cause higher retardation of development and fixation than normal-isoelectric-point gelatins. This phenomenon has been attributed to a stronger adsorption of the high-isoelectric-point gelatins. Gelatin impedes the regression of the latent image. A monolayer of gelatin is sufficient to prevent most of the fading. The exc...
TL;DR: In this paper, the reproduction of a periodic pattern at the limit of resolution, by practical application of the modulation object transfer function, seems to explain this apparent contradiction, while practice proves that it is a very useful criterion for the evaluation of photographic performance, particularly in aerial pholography.
Abstract: Photographic resolving power, defined by the number of parallel lines of a periodic bar pattern which can still be distinguished in the final reproduction, has been shown to be a subjective concept, while practice proves that it is a very useful criterion for the evaluation of photographic performance, particularly in aerial pholography. The computation of the reproduction of a periodic pattern at the limit of resolution, by practical application of the modulation object transfer function, seems to explain this apparent contradiction. It implies the multiplication of the frequency spectrum of the luminance distribution by the modulation transfer function of the photographic material and can be carried out with Fourier series on electronic computers. Investigation of the reproduction of bar patterns by this means not only yields results in good agreement with practical tests, but also shows that the reproduction tends to become independent, at the limit of resolution, of the exact form of the input...