Abstract: A process is disclosed of preparing a high bromide high aspect ratio tabular grain emulsion. At least a portion of grain growth is conducted in a temperature range of from 30.degree. to 90.degree. C. within a low pAg window and, during the low pAg grain growth, precipitation is conducted in the presence of chloride ion, which acts to offsets tabular grain thickening attributable to grain growth in the low pAg window.

Abstract: Disclosed is a silver halide photographic emulsion which comprises a dispersion medium and silver halide grains, wherein said silver halide grains are prepared by a process comprising the steps of:(a) preparing a dispersion medium, wherein said dispersion medium comprises a gelatin solution,(b) introducing an oxidizer into said dispersion medium; and(c) introducing silver halide seed grains.The silver halide emulsion provides a sliver halide photographic light-sensitive material high in sensitivity and excellent in pressure resistance.

Abstract: A silver halide photographic light-sensitive material includes at least one light-sensitive silver halide emulsion layer on a support. A silver halide emulsion contained in at least one emulsion layer contains grains having an average grain diameter of 0.3 .mu.m or more, an average grain thickness of less than 0.5 .mu.m and an average grain diameter/average grain thickness ratio of 2 or more in a percentage of at least 50% of a total projected area of emulsion grains. The emulsion is chemically sensitized in the presence of at least one compound represented by the following formula (I): ##STR1## wherein X represents hydrogen or alkaline metal, and R represents hydrogen, halogen or alkyl having 1 to 5 carbons.

Abstract: A silver halide emulsion contains light-sensitive silver halide grains in a binder. The silver halide emulsion is has been subjected to reduction-sensitization during grain formation and then added with at least one compound represented by the following formula (I), (II), or (III):R--SO.sub.2 S--M (I)R--SO.sub.2 S--R.sub.1 (II)R--SO.sub.2 S--L.sub.m --SSO.sub.2 --R.sup.2 (III)wherein R, R.sup.1, and R.sup.2 may be the same or different and represent an aliphatic group, an aromatic group, or a heterocyclic group, M represents a cation, L represents a divalent bonding group, and m represents 0 or 1. Compounds represented by formulas (I) to (III) may be polymers containing divalent groups derived from structures represented by formulas (I) to (III) as repeating unit. R, R.sup.1, R.sup.2, and L may be bonded to form a ring if possible.

Abstract: This invention provides a method of preparing a silver halide photographic emulsion which comprises adding to the silver halide emulsion before or during precipitation a non-labile chalcogen compound represented by Formula I:R.sup.1 --X.sup.1 --X.sup.2 --R.sup.2 (Formula I)It further provides a silver halide photographic emulsion prepared by the above method.

Abstract: A heat-developable photosensitive material includes an infrared-sensitive layer having a maximum spectral sensitivity at a wavelength of 700 nm or longer. A silver chlorobromide emulsion from which the infrared-sensitive layer is formed is prepared by adding an iodide at an intermediate stage during silver halide grain formation or later. The photosensitive material exhibits high sensitivity and low fog while the corresponding emulsion coating composition in solution form remains stable with time.

Abstract: A method for preparing a silver halide photographic emulsion containing silver halide grains , each of which has two or more phases different in the silver halide composition, comprising a step of growing silver halide grains, in which said silver halide grains are grown by supplying a solution of water-soluble silver salt and a solution of water-soluble halide, wherein fine grains of silver halide having a solubility product smaller than that of silver halide grains present in the course of growing silver halide grains are made present in the silver halide emulsion at a time during the grain-growth, iridium ions being individually added at a time when or after starting the grain-growth.

Abstract: A silver halide photographic light-sensitive material is provided, comprising silver halide-grains which meet the following requirements:(1) the silver halide grains are formed from seed crystals through the growth of the crystals, wherein a silver halide phase formed in each grain, before 30% of the addition amount of silver is supplied, is formed while the intergrain distance of individual silver halide grains contained in the reaction liquor being kept within a range of 0.1 to 2.0 .mu.m;(2) the silver halide grains each have, in respect of distance L from the grain center to the grain surface, a point at which the content of silver iodide becomes maximum within distance L.sub.1 from the grain center to 0.67 L, and a point at which the content of silver iodide becomes minimum within distance L.sub.2 from 0.58 L to the grain surface and, in each grain, the silver iodide content shows a substantially monotonous decrease in the range from L.sub.1 to L.sub.2, and (L.sub.2 -L.sub.1)/L>0.20 is satisfied.

Abstract: A process is disclosed of preparing a radiation sensitive silver halide emulsion comprising reacting silver and halide ions in a dispersing medium in the presence of a metal hexacoordination or tetracoordination complex having at least one organic ligand containing a least one carbon-to-carbon bond, at least one carbon-to-hydrogen bond, or at least one carbon-to-nitrogen-to-hydrogen bond sequence and at least half of the metal coordination sites occupied by halide or pseudohalide ligands. The metal forming the complex is chosen from periods 4, 5 and 6 and groups 3 to 13 inclusive of the periodic table of elements. The incorporation of the transition metal ion dopant and at least one organic ligand into the cubic crystal lattice of the silver halide grains can be used to improve photographic performance.

Abstract: Silver iodobromide tabular grain emulsions of enhanced photographic sensitivity are disclosed. The silver iodobromide grains contain from 2 to less than 10 mole percent iodide, exhibit a coefficient of variation of less than 20 percent, and consisting essentially of tabular grains having opposed parallel major faces. Each of the tabular silver bromoiodide grains exhibit an iodide concentration in excess of 6 mole percent within a surface region extending to a depth of less than 0.02 .mu.m and exhibit a central iodide concentration of less than 2 mole percent.

Abstract: A process for producing a silver halide photographic material and a photographic material produced thereby are disclosed. The process comprises the steps of (1) forming a seed emulsion comprising silver halide seed grains, (2) growing the seed grains to prepare a silver halide photographic emulsion by supplying a silver ion component and a halide ion component to the mother liquid of the seed emulsion, (3) coating and drying the photographic emulsion on a support to form the silver halide emulsion layer, and at least a period during the step for growing the seed grains is performed in the presence of silver iodide grains, and an oxidant capable of converting metallic silver to silver ions is added at a time during the step for growing the seed grains.

Abstract: A method for preparing a silver halide emulsion is disclosed. The silver halide emulsion comprises silver halide grains which are mixed crystals comprising: preparing a seed emulsion comprising seed grains; and adding potentially effective silver iodide grains comprising a silver halide micro grains having .gamma.-AgI structure, a soluble salt and a soluble halide to the seed emulsion.

Abstract: A silver halide photographic light-sensitive material comprising a support having thereon a silver halide emulsion layer containing silver halide grains which meet the following requirements (1) and (2):(1) the silver halide grains are formed in the presence of an oxidizing agent, and(2) the silver halide grains each have, in respect of distance L from the grain center to the grain surface, a point at which the content of silver iodide becomes maximum within distance L.sub.1 from the grain center to 0.67 L, and a point at which the content of silver iodide becomes minimum within distance L.sub.2 from 0.58 L to the grain surface and, in each grain, the silver iodide content shows a substantially monotonous decease in the range from L.sub.1 to L.sub.2, and(L.sub.2 -L.sub.1)/L>0.20is satisfied.

Abstract: The invention provides a method of measuring to control silver halide grain formation during nucleation and ripening comprisingcombining a source of silver ions and a source of halide ions to form a suspension of nucleated particles,removing a portion of said suspension,measuring turbidity of said portion,determining floc size from the turbidity measurement,determining the difference between floc size and individual silver halide nuclei size.

Abstract: A silver halide photographic light-sensitive material comprising a support and provided thereon, a silver halide emulsion layer comprising silver halide grains containing at least one substance selected from the group consisting gallium, germanium, indium, thallium and compounds thereof.

Abstract: A photosensitive silver halide photographic material having a support and, provided thereon, the photographic component layers including at least one silver halide emulsion layer containing silver halide grains (1) having at least two kinds of halogens, is disclosed. The silver halide grains (1) are grown to in a system in the presence of silver halide grains (2) coexisting:with silver halide grains which are growing to the silver halide grains (1),for at least some portion of period that said silver halide grains are growing in the system,and comprising solubility product less than that of said growing silver halide grains.

Abstract: A method of manufacturing a silver halide emulsion wherein spectral sensitizing dyes are added after the formation of silver halide grains, and chemically ripening is then carried out at a temperature higher than the addition temperature of the spectral sensitizing dyes at 25.degree. C. to 55.degree. C., is disclosed. A material produced by this method has a high linearity in gradation between the medium density part and the shoulder part, and having a high Dmax value.

Abstract: A method for the reproducible production of nonuniform distributions of polymolecular association clusters, each of the clusters comprising a plurality of a species A in association with a single species B, is disclosed. Species A is preferably a photographic dye and Species B is preferably a silver halide particle. The method comprises: (a) mixing a suspension of particles of species B in a vessel; (b) flowing a portion of the suspension through an isolated reaction zone; (c) introducing species A into the isolated reaction zone; and (d) returning the portion of the suspension including the introduced species A to the vessel. In another aspect, the invention relates to an apparatus for carrying out the foregoing process.

Abstract: The invention is generally accomplished by providing a tabular-grain silver halide emulsion in which at least 50 percent of the total grain projected area is accounted for by tabular grains having a mean diameter of at least 0.6 micrometer and a spacing between at least two parallel twin planes of less than about 0.011 micrometer. In a preferred form, at least 90 percent of the total grain projected area is accounted for by the tabular grains of the invention having a mean diameter of at least 0.6 micrometer and a spacing between at least two parallel twin planes of less than 0.012 micrometer.

Abstract: This invention provides a method of preparing a silver halide photographic emulsion which comprises adding to the silver halide emulsion after precipitation and before or during sensitization a disulfide compound and a sulfinate compound, wherein the disulfide compound and the sulfinate compound are added simultaneously. It further provides a silver halide photographic emulsion prepared by the above method.

Abstract: A method of image formation disclosed, which comprises a method of image formation comprising developing a photosensitive element comprising an image-wise exposed photosensitive silver halide emulsion layer using an alkaline processing element containing a silver halide solvent to convert at least a part of the unexposed silver halide in the emulsion layer to a transferrable silver complex salt, and transferring at least a portion of the silver complex salt onto an image-receiving element comprising an image-receiving layer containing silver precipitation nuclei to form an image in the image-receiving element, wherein the silver halide grain in the photosensitive silver halide emulsion layer comprises silver iodobromide or silver chloroiodobromide having a silver iodide content of from 0.5 to 3.5 mol %; and wherein silver bromide or silver iodobromide is formed after chemical sensitization on the surface of the grains in an amount of from 3 to 20% in terms of silver.

Abstract: Silver halide emulsions are disclosed in which at least 50 percent of total grain projected area is accounted for by tabular grains (1) bounded by {100} major faces having adjacent edge ratios of less than 10, (2) each having an aspect ratio of at least 2, and (3) internally at their nucleation site containing iodide and at least 50 mole percent chloride. The emulsions are prepared by a process comprised of the steps of (a) introducing silver and halide salts into a dispersing medium so that nucleation of the tabular grains occurs in the presence of iodide with chloride accounting for at least 50 mole percent of the halide present in the dispersing medium and the pCl of the dispersing medium being maintained in the range of from 0.5 to 3.5 and (b) following nucleation completing grain growth under conditions that maintain the {100} major faces of the tabular grains.

Abstract: A silver halide photographic emulsion contains silver halide grains comprising at least two portions, i.e., a core and an outermost shell with different silver halide compositions and having an average aspect ratio of less than 8. The core consists of silver iodobromide, silver chloroiodobromide, silver chlorobromide, or silver bromide. An average silver iodide content of the outermost shell is higher than that of the core and is 6 mol % or more. The silver halide grains are subjected to all of selenium sensitization, gold sensitization, and sulfur sensitization.

Abstract: This invention describes the advantages associated with the use of chain-extended acid processed ossein gelatin as the makeup gelatin, with emulsion precipitated in lime-processed ossein gelatin. Such photographic elements show a definite speed-fog advantage, compared to systems where standard lime-processed ossein gelatin is used solely.

Abstract: A method of producing a silver halide emulsion and a silver halide photographic light-sensitive material containing the emulsion are disclosed. The silver halide emulsion comprises light-sensitive silver halide grains containing at least one of first silver halide phases and at least one of second silver halide phases. The method comprises the steps of (a) forming the first silver halide phases in the presence of substantially one kind of first fine silver halide grains, said first silver halide phases having a silver halide composition different from that of the first fine silver halide grains, and (b) forming the second silver halide phases by supplying second fine silver halide grains having a solubility product higher than that of the first fine silver halide grains.

Abstract: An improvement in tabular grain manufacture is provided wherein large tabular grains can be prepared in less time and with a narrower size distribution than available in the art. The improved process includes the steps of:a) forming a nucleation solution by adding aqueous soluble silver salt to a vessel containing 0.08 to 0.25 molar aqueous soluble halide salt in an aqueous medium;b) adding a solution of ammoniacal base to said nucleation solution when 0.30 to 9.0% of said soluble silver salt has been added;c) optionally ripening said nucleation solution for up to 60 minutes;d) adding said soluble silver salt to said nucleation solution preferrably at an increasing rate to obtain growth pBr of 1.3 to 2.3;e) adding said soluble silver salt and said soluble halide salt to grow said tabular grains.

Abstract: A process and apparatus for precipitating a silver halide emulsion is disclosed. The process is comprised of the steps of adding silver ions to a dispersing medium containing halide ions within a reaction vessel to initiate growth of silver halide grains within the dispersing medium, monitoring the temperature of the dispersing medium to establish the equilibrium solubility product constant of silver and halide ions within the dispersing medium; concurrently, using a reference electrode and a first indicator electrode, monitoring the halide ion activity within the dispersing medium; and adjusting the level of dissolved halide ion in the reaction vessel to maintain a stoichiometric excess of halide ions, based on the equilibrium solubility product constant.

Abstract: There is disclosed a method for preparing a direct reversal type silver halide light-sensitive emulsion which is used for a black-and-white light-sensitive material and has the improved photographic performances of a high sensitivity and a high contrast. The method comprises:A method for preparing a fogging type direct positive silver halide emulsion comprising the steps of:(a) forming an emulsion containing silver halide grains;(b) fogging surfaces of the grains with a reducing agent to form a silver nuclei; and then(c) performing at least one of an adjustment of pH of the emulsion to 4.5 or less and an adjustment of pAg of the emulsion to 8.1 or more.

Abstract: A radiation sensitive emulsion is disclosed containing a high chloride {100} tabular grain population in which the tabular grains contain bands of higher iodide.

Abstract: There is disclosed a silver halide photographic light-sensitive material having an excellent interimage effect and gradation property. The light-sensitive comprises at least one light-sensitive layer containing silver bromoiodide emulsion consisting primarily of the twinned grains, wherein in an X-ray diffraction diagram which is obtained by subjecting the silver bromoiodide grains to a (420) X-ray diffraction with a CuK.alpha. ray, an intercept between the intersection points of a maximum peak diagram and a line drawn horizontally at a point of 0.13 times the height of the maximum peak corresponds to not less than 1.5 degree of a diffraction angle (2.theta.).

Abstract: A process for preparing a photographic emulsion involves an initial nucleation step of reacting a first silver salt with a bromide in the presence of a first excess halide under conditions effective to nucleate AgBr crystals. The nuclei are then grown to form photosensitive grains by addition of a second silver salt and a second halide as growth salts. If excess chloride is used during nucleation, even without excess bromide and/or a growth modifier, the nuclei formed have twin planes, and the pAg level can be used to control the aspect ratio of the tabular grains obtained. If a relatively high silver concentration in the growth solution is maintained throughout the growth step, the resulting grains have a unique, twinned cubooctahedral or cubooctahedral-tabular shape. Unique tabular grains having alternating 1.1.1 and 1.0.0 edge faces can be formed by this process.

Abstract: A negative type silver halide photographic material having silver halide grains of a core-shell structure. An inner core essentially consists of silver bromide or silver iodobromide and a plurality of shells consists essentially of silver bromide or silver iodobromide. The shells of each silver halide grain have (1) an outermost shell containing silver iodide of 0 to 10 mol %, (2) a highly iodide-containing shell provided inside the outermost shell and having a silver iodide content at least 6 mol % higher than that of the outermost shell, and (3) an intermediate shell provided between the outermost shell and the high iodide-containing shell. The silver iodide content of the intermediate shell is 3 mol % higher than that of the outermost shell and at least 3 mol % lower than that of the high iodide-containing shell.

Abstract: The present invention relates to a device for preparing a photographic liquid which is to be applied in the manufacture of a photographic photosensitive material wherein multiple layers of photographic liquids are applied simultaneously. The present invention has at least one chemical measuring station which measures various kinds of chemicals sent from chemical storage tanks and prepares a photographic liquid which is to be applied to a film, supplies the measured chemicals to a pot and a conveys the chemicals in the pot to a hopper from which the chemicals are supplied to a liquid preparation tank.

Abstract: A novel photographic silver halide emulsion is disclosed, which is useful in a color photographic silver halide material to provide improvements in image quality, storage stability and pressure resistance. The photographic silver halide emulsion comprises silver halide twinned crystal grains each having a ratio of grain diameter to grain thickness of 5 or less which amount to 50% or more by projection area of total grains, wherein X-ray diffraction pattern of the twinned crystal grains with Cu-K.alpha. ray as a radiation source has a (420) diffraction signal having a single peak; and the width of the peak at a height of 0.13 times the maximum peak height, based on the signal intensity, is 1.5 degree or less in a diffraction angle, 2.theta..

Abstract: A direct positive photographic light-sensitive material comprises a support and a light-sensitive emulsion layer provided thereon which contains non-pre-fogged internal latent image type silver halide grains of a core/shell structure. The cores of the silver halide grains are treated with a spectral sensitizing dye and a chemical sensitizer.

Abstract: A novel silver halide color photographic material is provided which is excellent in color reproduction and color image fastness, and shows only small variations in gradation due to fluctuaion in treatment conditions such as treatment composition, time, and temperature. The present silver halide color photographic material has a pyrazoloazole coupler and silver halide grains consisting of regular crystals with a twin content of 5% or less, said silver halide grains being represented by the formula:AgCl.sub.x Br.sub.y I.sub.l-x-ywherein x and y satisfy the relationships 0.ltoreq.x<1, 0.ltoreq.y.ltoreq.1, and 0.ltoreq.l-x-y.ltoreq.0.02.In preferred embodiments of the present invention, said pyrazoloazole coupler is represented by the general formula: ##STR1## wherein R.sub.

Abstract: A method is disclosed of extracting two or more spectral image records from an imagewise exposed multicolor photographic element containing a plurality of tabular grain emulsions for individually recording imagewise exposure in at least two different regions of the visible spectrum. In each of the tabular grain emulsions tabular grains exhibiting a mean equivalent circular diameter of greater than 0.4 micrometer and a mean thickness of less than 0.2 micrometer account for greater than 90 percent of total grain projected area. No more than one of the tabular grain emulsions exhibits a mean tabular grain thickness of less than 0.07 micrometers, and each of the remaining tabular grain emulsions exhibit a coefficient of variation of tabular grain thickness of less than 15 percent. The mean tabular grain thickness of emulsions for recording imagewise exposure to different regions of the visible spectrum differs by at least 0.02 micrometer.

Abstract: The present invention is a method to add dry gelatin to a photographic emulsion in either a liquid or a solid form. The dry gelatin is added by entraining the dry gelatin in air to form a gaseous mixture of dry gelatin in air and directing this mixture into the solid or liquid photographic emulsion. An air eductor is used to deliver the dry gelatin. When adding dry gelatin to a solution, the rate is determined by the solution viscosity and volume. When adding the dry gelatin to a solid emulsion, the dry gelatin rate is not as critical but uniform addition is still needed to interdisperse the dry gel with the emulsion pellets.

Abstract: A method for controlling pressure-induced fog in a silver bromide photographic material involves surface treatment of the emulsion AgBr grains with thiocyanate and an iodide salt. In particular, a process for making a pressure fog-resistant photographic emulsion includes steps of forming a photographic emulsion containing cubic or cubooctahedral silver bromide grains, surface-treating the AgBr grains with a thiocyanate by adding the thiocyanate to the emulsion, chemically sensitizing the emulsion, maintaining the emulsion at a temperature and for a time sufficient to allow the thiocyanate to react with the grain surfaces, and then surface-treating the AgBr grains with an iodide salt by adding the salt to the emulsion in an amount and under conditions effective to fill in cubic faces of the AgBr grains. The latter step partially or fully converts the AgBr grains to octahedral grains. A photographic element can then be made by coating the emulsion on a suitable base.

Abstract: A process is disclosed of preparing an emulsion comprised of dispersing medium and folded tabular grains containing at least 95 mole percent chloride, based on total silver. This is achieved by maintaining a chloride ion concentration of at least 0.5 molar in the dispersing medium while the grain nuclei are being formed and during grain growth maintaining in the dispersing medium a pH in the range of from 1 to 8 and an effective concentration of 2-hydroaminoazine or xanthinoid morphological modifier in the range of from a 5.times.10.sup.-5 to 2.times.10.sup.-2 millimolar concentration.

Abstract: A process is disclosed of preparing an emulsion for photographic use comprised of silver halide grains and a gelatino-peptizer dispersing medium in which morphologically unstable tabular grains having {111} major faces account for greater than 50 percent of total grain projected area and contain at least 50 mole percent chloride, based on silver. The emulsion additionally contains at least one 2-hydroaminoazine adsorbed to and morphologically stabilizing the tabular grains. Protonation releases 2-hydroaminoazine from the tabular grain surfaces into the dispersing medium. Released 2-hydroaminoazine is replaced on the tabular grain surfaces by adsorption of a photographically useful 5-iodobenzoxazolium compound, thereby concurrently morphologically stabilizing the tabular grains and enhancing their photographic utility, and the released 2-hydroaminoazine is removed from the dispersing medium.

Abstract: A process is disclosed of preparing an emulsion for photographic use comprised of silver halide grains and a gelatino-peptizer dispersing medium in which morphologically unstable tabular grains having {111} major faces account for greater than 50 percent of total grain projected area and contain at least 50 mole percent chloride, based on silver. The emulsion additionally contains at least one 2-hydroaminoazine adsorbed to and morphologically stabilizing the tabular grains. Protonation releases 2-hydroaminoazine from the tabular grain surfaces into the dispersing medium. Released 2-hydroaminoazine is replaced on the tabular grain surfaces by adsorption of a photographically useful benzimidazolium dye, thereby concurrently morphologically stabilizing the tabular grains and enhancing their photographic utility, and the released 2-hydroaminoazine is removed from the dispersing medium.

Abstract: An in-line process for mixing solvents with amorphous particle dispersions is disclosed. Continuous emulsification of the solvent is achieved by an in-line high-shear mixer, and diffusion of solvent to the amorphous particles is controlled in a plug flow reactor. Both processes are conducted in-line during dispersion delivery to coating processes. An apparatus for carrying out the process is also disclosed.

Abstract: A silver halide photographic material is descloosed, comprising a support having thereon at least one silver halide emulsion layer, wherein the silver halide emulsion layer contains at least 1.times.10.sup.-4 mol of a compound represented by formula (I) per mol of silver halide and from 1.times.10.sup.-3 to 1.times.10.sup.-1 mol of compound represented by formula (II) per mol of the compound of formula (I) and the iodine content of the silver halide emulsion is 1 mol % or less: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, Z.sub.1, Z.sub.2, Z.sub.3, Z.sub.4, X.sup..crclbar. and n are defined in the specification. The photographic material is highly sensitive, can be processed rapidly, and does not fatigue the developer, yet it contains only a small percentage of iodine, if any. The photographic material is useful in photographic films including X-ray films.

Abstract: A radiation sensitive emulsion is disclosed containing a silver halide grain population internally free of iodide at the site of grain nucleation comprised of at least 50 mole percent chloride, based on total silver forming the grain population, in which greater than 30 percent of the grain population projected area is accounted for by tabular grains having a mean thickness of less than 0.3 .mu.m. The tabular grains combine high tabularities and relatively high aspect ratios with exceptional stability imparted by parallel major faces lying in {100} crystallographic planes.

Abstract: An emulsion layer containing silver halide grains reduction-sensitized by an ascorbic acid or at least one of its derivatives and containing a nitrogen-containing heterocyclic compound having a mercapto group is formed on a support.

Abstract: A photographic silver halide emulsion comprised of a high chloride silver iodohalide grain structure in which the proportion of iodide has been increased.

Abstract: A photographic silver halide emulsion comprising silver chlorobromide grains containing at least 80 mol % silver chloride or silver chloride grains is disclosed, wherein tabular grains having a thickness of less than 0.5 .mu.m, a diameter of at least 0.5 .mu.m and an aspect ratio of at least 2/1 account for at least 50% of the total projected area of the silver halide grains, and the tabular grains are formed in the presence of a compound of metal belonging to Group VIII of the Periodic Table. The high silver chloride content emulsion has a sensitivity as high as that of a silver iodobromide emulsion.

Abstract: A silver halide photographic material which comprises a support having thereon at least one silver halide emulsion layer, wherein silver halide grains to be contained in the silver halide emulsion layer have a silver iodide content lower than 1 mol %, and the silver halide emulsion contains 3.0.times.10.sup.-3 to 2.times.10.sup.-2 mol of a thiocyanate per mol of silver halide. In addition, a photographic silver halide emulsion comprising silver halide grains wherein said silver halide grains have an average silver iodide content lower than 1 mol %, and deposited on the surface of the silver halide grains is at least 2.times.10.sup.-3 mol, but less than 2.times.10.sup.2 mol of a thiocyanate per mol of silver halide.

Abstract: There is disclosed a novel direct positive silver halide emulsion and a color diffusion transfer photographic film unit in which the above emulsion is used and which provides a high sensitivity and a low minimum density. The direct positive silver halide emulsion contains a core/shell type grain in which 60% or more of the projected area of all grains is shared by a monodispersed parallel twin crystal-containing type tabular grain having an aspect ratio of 1.5 or more, wherein the shell of the core/sell grain is formed by adding a silver salt in which at least 30 mole % of the silver salt is a non-twin crystal silver halide fine grain emulsion having an average grain size of 0.12 .mu.m or less.