Abstract: A photographic silver halide emulsion comprised of a silver halide grain structure containing chloride, bromide and iodide ions in which the molar ratio of bromide ions to chloride ions ranges from 9:1 to 1:1 and the proportion of iodide has been increased.

Abstract: A method for preparing silver halide emulsion grains by a crystal growth method comprising feeding fine silver halide grains to a reaction vessel containing seed crystals of a silver halide emulsion and dissolving the fine grains in the reaction vessel by Ostwald ripening to grow said seed crystals, wherein the fine grains are non-twinned crystal fine grains having substantially no twinning plane.

Abstract: A multicolor photographic element capable of forming a viewable reversal dye image is disclosed comprising a support and, coated on the support, a blue recording yellow dye image forming layer unit, a green recording magenta dye image forming layer unit, and a red recording cyan dye image forming layer unit, each of the dye image forming layer units containing at least one silver halide emulsion layer comprised of a vehicle and silver halide grains having (1) a halide content of from 0 to 5 mole percent chloride, from 0.1 to 20 mole percent iodide, and from 80 to 99.9 mole percent bromide, based on total silver. At least one of the silver halide emulsion layers in one of the layer units positioned to receive exposing radiation prior to at least one of the green or red recording layer units is a tabular grain emulsion layer in which a polyalkylene oxide block copolymer is present selected to allow the preparation of tabular grains having a mean thickness of less than 0.3 .mu.

Abstract: In a method of manufacturing a silver halide emulsion which comprises a silver chlorobromide having a silver chloride content of 90 mol% or more or silver chloride and said silver halide containing substantially no silver iodide, the improvement which comprises the steps of,(i) adding to a reactor a compound capable of spectrally sensitizing the silver halide emulsion in a wavelength range between 590 nm and 720 nm, and(ii) then adding to the reactor a compound capable of spectrally sensitizing the silver halide emulsion in a wavelength range between 390 nm and 590 nm,prior to the completion of chemical sensitization of the silver halide emulsion, and color photographic material having the emulsion manufactured by the method.

Abstract: A silver halide photographic material comprising a support having thereon at least one light-sensitive silver halide emulsion layer containing silver halide grains, wherein said silver halide grains have a silver chloride content of 30 mol% or more and contain (i) and iridium compound in an amount of 10.sup.-6 mol or less per mol of silver halide, (ii) at least one compound selected from the group consisting of iron, rhenium, ruthenium and osmium compounds in an amount of 10.sup.-3 mol or less per mol of silver halide, and (iii) (a) at least one compound selected from the group consisting of compounds represented by general formula (1-a), (1-b) and (1-c): ##STR1## wherein Z represents a C.sub.1-18 alkyl group, a C.sub.6-18 aryl group or a heterocyclic group; Y represents an atomic group required for the formation of a C.sub.

Abstract: A quick-developing highly sensitive silver halide emulsion distinguished by steep gradation, a minimal increase in fog during storage, improved threshold gradation and low sensitivity to below-threshold pre-exposure is obtained by the addition of a diindoyl disulfide during preparation of the emulsion.

Abstract: A process for preparation of a light-sensitive material containing microcapsules is disclosed. The light-sensitive material comprises a light-sensitive layer provided on a support. The microcapsules are dispersed in the light-sensitive layer. The process of the present invention comprises the steps of: (1) mixing a silver halide emulsion and the reducing agent or the photopolymerization initiator with the polymerizable compound to prepare a light-sensitive composition; (2) emulsifying the composition in an aqueous medium to prepare an aqueous emulsion; (3) forming a shell around the droplets of the composition contained in the aqueous emulsion to prepare a microcapsule dispersion; (4) coagulating the aqueous medium to set the microcapsule dispersion; (5) storing the set microcapsule dispersion; (6) melting the aqueous medium to prepare a coating solution of the light-sensitive layer; and (7) coating the solution on the support.

Abstract: Disclosed is a light-sensitive silver halide photographic material having at least one layer containing a silver halide emulsion on a support, wherein at least one layer containing said silver halide emulsion contains a silver halide emulsion having at least partially silver halide grains formed by the fine grain feeding method, and said support has a thickness of 25 .mu.m to 120 .mu.m.

Abstract: A process for producing a light-sensitive silver halide emulsion comprising the steps of:(a) batchwise reacting in a first medium-sized reaction vessel an aqueous solution of a silver salt and an aqueous solution of a halide salt to form a silver halide emulsion comprising silver halide grains;(b) transferring said silver halide emulsion to a second medium-sized reaction vessel;(c) adding an aqueous silver salt solution and an aqueous halide salt solution or silver halide fine grains having a average diameter of at most 0.1 .mu.m to said silver halide emulsion in said second medium-sized reaction vessel and batchwise reacting said mixture to grow silver halide on said silver halide grains;(d) subsequently transferring the silver halide emulsion from said second medium-sized reaction vessel to a third medium-sized reaction vessel; and(e) batchwise subjecting said silver halide emulsion in said third medium-sized reaction vessel to at least one of desalting, chemical ripening or chemical sensitization.

Abstract: A silver halide photographic material comprising a support having thereon at least one silver halide emulsion layer wherein the silver halide emulsion contains a salt of a metal ion of which the atomic number is at least 21 alone or together with a chelating agent and wherein the silver halide emulsion has been chemically sensitized in the presence of a chemical sensitization promoter comprising at least one of a silver halide solvent and an adsorbable compound.

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 absorbed 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 compound selected from among those that contain at least one divalent sulfur atom, thereby concurrently morphologically stabilizing the tabular grains and enhancing their photographic utility, and the released 2-hydroaminoazine is removed from the dispersing medium.

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 before or during sensitization 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: This invention provides a method of preparing a silver halide photographic emulsion which comprises adding to the silver halide emulsion a solid particle dispersion of 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 silver halide photographic emulsion containing silver halide twinned-crystal grains is prepared by the steps of (a) forming silver halide nuclear grains by mixing a water soluble silver salt and a water soluble halide, (b) forming silver halide seed-emulsion grains by carrying out ripening of the nuclear grains formed in (a), and (c) growing the seed-emulsion grains, wherein a water soluble polymer is introduced by (b), having the repetition unit represented by the following formula [P] in an amount of 10 to 100 mol % per each polymer molecule: ##STR1##

Abstract: An apparatus for forming silver halide grains comprises a reaction vessel for causing the nucleus formation and the crystal growth of silver halide grains. The apparatus further includes: a mixer disposed outside of the reaction vessel and having a high-speed stirring blade; conduits for supplying an aqueous solution of a water-soluble silver salt, an aqueous solution of water-soluble halide, and an aqueous protective colloid solution to the mixer while controlling the rotational speed of the high-speed stirring blade to form fine, silver halide grains; and a conduit for connecting the mixer to the reaction vessel for immediately supplying the fine grains in the mixer to the reaction vessel.

Abstract: A color image forming process is disclosed. The process comprises color developing an imagewise exposed silver halide color photographic material with a developer containing an aromatic primary amine color developing agent, after successive steps of desilvering, washing and/or stabilizing, and drying, wherein said color photographic material has at least one silver halide emulsion layer containing silver halide grains containing substantially no silver iodide and containing at least 95 mol % silver chloride based on the total silver halide content, said silver halide grains further containing from 1.times.10.sup.-6 to 1.times.10.sup.-3 mol of an iron compound per mol of silver and said iron compound being distributed at an iron ion concentration in the surface phase of the grain of at least 5 times that in the inside phase of the grain,wherein the total gelatin weight of said color photographic material is 7 g or less per m.sup.

Abstract: A photographic emulsion is disclosed containing a coprecipitated grain population exhibiting a coefficient of variation of less than 10 percent. The coprecipitated grain population consists essentially of tabular grains which are at least 50 mole percent bromide, based on silver, and which have a mean thickness in the range of from 0.080 to 0.3 .mu.m, and a mean tabularity of greater than 8.

Abstract: A method for producing a silver halide photographic emulsion comprising silver iodobromide or iodobromochloride grains having an average iodine content of less than 1.0 mol %, which comprises the following step (a) or (b) to form a surface portion of the grains such that the step provides the surface portion having an iodine content of 0.005 mol % to less than 0.3 mol % based on the total amount of silver in the grains:(a) adding simultaneously a silver nitrate solution and a solution which contains iodine ion; or(b) adding fine particles of AgI and/or fine particles of AgBrI.The emulsion thus produced is suitable for photosensitive materials which are subjected to ultra-rapid automatic development processing.

Abstract: A novel silver halide color reversal photographic material is provided having at least one light-sensitive silver halide emulsion layer on a support, comprising silver halide grains contained in said at least one silver emulsion layer, said silver halide grains consisting of a core phase comprising the center thereof and a shell phase covering said core phase and comprising the surface thereof, and silver iodide content of said shell phase being higher than that of said core phase.

Abstract: A method for manufacturing a silver halide emulsion. By the method, a silver halide emulsion comprising monodisperse silver halide grains having a high aspect ratio can be manufactured without use of low molecular weight gelatin. The method has the steps offorming nuclei of silver halide grains by adding a water-soluble silver salt and a water-soluble halide salt to a protective colloid solution,applying Ostwald ripening to the precipitation nuclei to form seed grains of silver halide at a temperature lower than the temperature at which the silver halide nuclei are formed, to form silver halide seed grains which mainly comprises twin grains having an average grain size of less than 0.25 .mu.m and less than 50% of a surface area of each of the seed grains is occupied with {100} surface,growing the seed grains by adding a component to forming a silver halide to a liquid containing the seed grains.

Abstract: A process and apparatus for mass-producing a silver halide emulsion for photographic light-sensitive materials which includes carrying out the nucleation of the silver halide grains in a reaction apparatus having a middle capacity and carrying out physical ripening and/or the crystal growth in a reaction apparatus having a larger capacity than the middle capacity reaction apparatus. Another reaction apparatus having a larger capacity than the middle capacity reaction apparatus can be used to store nuclei formed in the middle capacity reaction apparatus before transfer of the nuclei to the other reaction apparatus having a large capacity in which physical ripening and/or the crystal growth are carried out.

Abstract: There is disclosed a silver halide photographic material having a photosensitive emulsion layer on a base, comprising a high-silver-chloride silver chlorobromide emulsion which is obtained by mixing silver halide host grains with silver halide fine grains and then ripening, thereby forming, on or near the surfaces of silver halide grains, silver bromide localized phases, wherein the formation of the localized phases or the chemical sensitization of the surfaces is carried out at a limited temperature. The disclosure described provides a silver halide photographic material suitable for rapid processing, high in sensitivity, and good in safelight aptitude and abrasion pressure and resistance.

Abstract: A method for preparing a silver halide emulsion containing silver halide grains comprising(i) preparing a mixture by mixing a compound represented by the following Formula (1) or (2), and a gold compound; and(ii) performing chemical ripening of the emulsion by adding said mixture thereto: ##STR1## wherein M, R, V and W independently represent a hydrogen atom or a substituent group; V and W may combine with each other to form a ring.

Abstract: A method of preparing a superfine grain emulsion with a grain size of 0.05 .mu.m or less is provided, which includes mixing aqueous solutions of a water-soluble silver salt and a water-soluble halide with vigorous stirring inside a closed mixing device furnished with an agitator, where the solutions are fed into the device simultaneously and continuously, in the presence of at least one of a high molecular compound and a substance capable of adsorbing to silver halide, each of which has a physical retardance value of at least 40 as determined by PAGI method, and immediately expelling the newly-formed grains from the mixing device. Another method includes mixing the aqueous solutions in a mixing device as described above, immediately expelling the newly-formed grains from the device, and mixing the expelled grains with at least one of the above-described high molecular compound and substance.

Abstract: A method for spectrally sensitizing silver halide emulsions is disclosed, comprising the step of adding a cyanine dye, which provides a J-band when added to silver halide emulsions, to a silver halide emulsion followed by ripening with such conditions that the relative quantum yield .phi..sub.r of spectral sensitization assumes a value of 1/2 or less of the .phi..sub.r of spectral sensitization obtained when the dye is added to the emulsion under ripening conditions of 40.degree. C. and 20 minutes from the time of addition of the dye to the emulsion until the time of coating the emulsion, and then ripening the silver halide emulsions. In one embodiment of the disclosed method, a heterocyclic compound which contains a mercapto group is added to the emulsion before the addition of the dye in an amount sufficient to increase the .phi..sub.r.

Abstract: A negative silver halide photographic material comprising a support having thereon at least one light-sensitive silver halide emulsion layer containing a silver halide emulsion containing regular silver halide grains containing from 0.3 mol % to 3.0 mol % of silver iodide, the silver halide grains being produced by conversion of silver halide host grains using high silver iodide silver halide grains having a silver iodide content of at least 90 mol % in an amount sufficient to provide from 0.1 mol % to 2.5 mol % of silver iodide based on the total silver halide content of the silver halide host grains and the high silver iodide grains.The photographic material containing silver halide grains having a novel structure provides a negative image having excellent photographic characteristics, particularly high sensitivity and ultrahigh contrast.A method of forming an ultrahigh contrast image which is excellent in line image quality using a stable developing solution is also disclosed.

Abstract: A process of preparing a radiation sensitive high chloride high aspect ratio tabular grain emulsion is disclosed wherein silver ion is introduced into a gelatino-peptizer dispersing medium containing a stoichiometric excess of chloride ions with respect to the silver ions further characterized by a chloride ion concentration of less than 0.5 molar, a pH of at least 4.6, and a triaminopyrimidine grain growth modifier containing mutually independent 4, 5 and 6 ring position amino substituents, the 4 and 6 ring position substituents being hydroamino substituents.

Abstract: Disclosed is an autopositive silver halide photographic material which comprises at least one silver halide emulsion layer, characterized in that said emulsion layer or at least one other hydrophilic colloid layers contains at least one compound selected from the group consisting of compounds represented by the following general formulas (1), (2) and (3): ##STR1## wherein R.sub.1 represents hydrogen atom or an alkyl group; and R.sub.2, R.sub.3 and R.sub.4 each represents hydrogen atom, a halogen atom, an alkyl group or an alkoxy group; ##STR2## wherein R.sub.5 represents hydrogen atom or an alkyl group; and R.sub.6 and R.sub.7 each represents hydrogen atom, an alkyl group, a halogen atom or an aryl group; ##STR3## wherein R.sub.8 represents a lower alkylene group; X represents a halogen atom, nitro group, hydroxy group, a cyano group, a lower alkyl group, a lower alkoxy group, ##STR4## or --SO.sub.3 M; R.sub.12 represents hydrogen atom, --OM, a lower alkyl group, a lower alkoxy group or ##STR5## R.sub.

Abstract: A silver halide photographic light-sensitive material improved in gradation and processing stability is disclosed. The material has a support and provided thereon a blue-sensitive emulsion layer, a green-sensitive emulsion layer and red-sensitive emulsion layer, wherein at least one of said color-sensitive emulsion layers contains; tabular silver halide grains having an aspect ratio of not less than 1.2; and core/shell type regular crystal silver halide grains of which the average projection area accounts for not more than 40% of that of the tabular grains.

Abstract: A process of preparing a radiation sensitive high chloride high aspect ratio tabular grain emulsion is disclosed wherein silver ion is introduced into a gelatino-peptizer dispersing medium containing a stoichiometric excess of chloride ions with respect to the silver ions further characterized by a chloride ion concentration of less than 0.5 molar, a pH of at least 4.6, and a grain growth modifier of the formula: ##STR1## where N.sup.4 is an amino moiety andZ represents the atoms completing a 5 or 6 member ring.

Abstract: The present invention relates to a method for obtaining a silver halide photographic composition for a coating layer. The method consists in individually preparing the various components of the desired layer, comprising at least one silver halide emulsion, and solutions or dispersions containing one or more finishing addenda and/or gelatin, chilling these components to solidify each of them, cutting them into chunks, cold-blending, in a solid state, the components selected according to the formulation of the desired layer, and liquefying the resulting solid composition just before its introduction into the coating station. The method can be applied to all types of silver halide photographic products, for black and white or color photography.

Abstract: A process for improving the method by which a powder such as a dye is added to a gelatino silver halide element is described. This process involves encapsulating the powder within a gelatin capsule. This process avoids cross-contamination and dusting when powder is added to solvent and also reduces the use of extra solvent in the manufacture of the element.

Abstract: A process of preparing a radiation sensitive high chloride high aspect ratio tabular grain emulsion is disclosed wherein silver ion is introduced into a gelatino-peptizer dispersing medium containing a stoichiometric excess of chloride ions with respect to the silver ions further characterized by a chloride ion concentration of less than 0.5 molar and a grain growth modifier of the formula: ##STR1## where Z.sup.8 is --C(R.sup.8).dbd. or --N.dbd.;R.sup.8 is H, NH.sub.2 or CH.sub.3 ; andR.sup.1 is hydrogen or a hydrocarbon of from 1 to 7 carbon atoms.

Abstract: A process of preparing a radiation sensitive high chloride high aspect ratio tabular grain emulsion is disclosed wherein silver ion is introduced into a gelatino-peptizer dispersing medium containing a stoichiometric excess of chloride ions a chloride ion concentration of less than 0.5 molar and a grain growth modifier of the formula: ##STR1## where Z.sup.2 is --C(R.sup.2).dbd. or --N.dbd.;Z.sup.3 is --C(R.sup.3).dbd. or --N.dbd.;Z.sup.4 is --C(R.sup.4).dbd. or --N.dbd.;Z.sup.5 is --C(R.sup.5).dbd. or --N.dbd.;Z.sup.6 is --C(R.sup.6).dbd. or --N.dbd.;with the proviso that no more than one of Z.sup.4, Z.sup.5 and Z.sup.6 is --N.dbd.;R.sup.2 is H, NH.sub.2 or CH.sub.3 ;R.sup.3, and R.sup.4 and R.sup.5 are independently selected, R.sup.3 and R.sup.5 being hydrogen, hydroxy, halogen, amino or hydrocarbon and R.sup.4 being hydrogen, halogen or hydrocarbon, each hydrocarbon moiety containing from 1 to 7 carbon atoms; andR.sup.6 is H or NH.sub.2.

Abstract: A process is disclosed of preparing a high chloride tabular grain emulsion for photographic use. An emulsion 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, is formed in the presence of at least one 2-hydroaminoazine or xanthinoid morphological stabilizer adsorbed to surfaces of the tabular grains. Chemical sensitization of the emulsion and protonation of the morphological stabilizer are performed at least in part concurrently. Termination of protonation of the morphological stabilizer retains a portion of the morphological stabilizer on the surfaces of the chemically sensitized tabular grains.

Abstract: A method for forming a photographic element includes steps of heating an emulsion containing grains of a radiation sensitive silver haloiodide to form a first melt, heating an emulsion containing grains of a silver salt effective to enhance the photographic properties of the silver haloiodide emulsion to form a second melt, and coating the first and second melts onto a photographic support to form an image recording layer. The silver salt grains are substantially insensitive to radiation at wavelengths at which said silver haloiodide grains are sensitive. The coating step is preferably carried out by blending the first and second melts together, then immediately coating the silver haloiodide emulsion onto the support. In a preferred embodiment, the silver salt is essentially silver chloride in the form of relatively fine cubic grains, and the silver haloiodide is in the form of tabular grains larger than the cubic grains.

Abstract: There is disclosed a silver halide photographic material comprising a photosensitive emulsion layer containing a nitrogen-containing heterocyclic compound and a silver halide emulsion of high-silver-chloride, which emulsion has been spectrally sensitized with a red-sensitive sensitizing dye having a definite reduction potential value, and which has been subjected to reduction sensitization. The disclosure as described provides a silver halide photographic material that is excellent in rapid processing and high in sensitivity and wherein there is little change of photographic performance.

Abstract: A process is disclosed of preparing an emulsion for photographic use comprising forming in the presence of an xanthinoid grain growth modifier an emulsion 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. After the emulsion is formed, the pH of the emulsion is lowered to inactivate xanthinoid grain growth modifier, and the inactivated xanthinoid is replaced on the tabular grain surfaces by adsorption of a photographically useful compound chosen to contain at least one divalent sulfur atom, thereby concurrently morphologically stabilizing the tabular grains and enhancing their photographic utility.

Abstract: There is disclosed a silver halide color photographic light-sensitive material which is improved in image sharpness, pressure resistance and sweating. The photographic material comprises a support and provided thereon a coupler-containing layer, wherein said coupler-containing layer has substantially no high-boiling solvent; and said coupler-containing layer or another layer comprises a silver halide emulsion containing silver halide grains which are formed by supplying silver halide fine grains.

Abstract: A process is disclosed of preparing a photographic emulsion containing tabular silver halide grains exhibiting a reduced degree of total grain dispersity. After forming a population of silver halide grain nuclei containing parallel twin planes, ripening out a portion of the silver halide grain nuclei. The silver halide grain nuclei containing parallel twin planes remaining are then grown to form tabular silver halide grains. The total grain dispersity of the emulsion is reduced by incorporating bromide ion in the dispersing medium prior to forming the silver halide grain nuclei and, at the time parallel twin planes are formed in the silver halide grain nuclei, a polyalkylene oxide block copolymer surfactant containing terminal hydrophilic alkylene oxide block units linked by a lipophilic alkylene oxide block unit accounting for at least 4 percent of the molecular weight of the copolymer.

Abstract: An improved process for preparing silver halide emulsions by precipitation of silver halide grains in a single reaction vessel comprising a dispersing medium is disclosed. The process comprises forming a silver halide emulsion by adding silver salt and halide salt solutions in a dispersing medium contained in a reaction vessel to form silver halide nuclei and allowing said silver halide nuclei to grow in said reaction vessel. The improvement comprises, during a pause of addition of silver salt and halide salt solutions, reducing the volume of silver halide emulsion by continuously delivering the silver halide emulsion to a cleaning stage for the partial removal of dispersing medium and any salt soluble therein and returning the silver halide emulsion to the reaction vessel.

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: The incorporation of dopant during the precipitation of silver halide grains. The silver halide grains are formed by a double jet, accelerated flow technique. After addition of about 65 to 90% of the silver halide mass to be precipitated, a dopant solution of an Group VIB salt in an amount of between about 0.2 and about 1.0 mg salt per mole of silver is added to the precipitation dispersion. The dispersion formation is then allowed to complete by continuing the double jet precipitation technique until a desired grain size is reached. Grains formed by this process will have their outer third comprising the Group VI metal salt with the silver halide. In the preferred method the Group VIB metal salt added is a selenium salt comprising potassium selenocyanate.

Abstract: A method and apparatus for manufacturing photographic photosensitive solultion to produce crystals of silver halide emulsion having a uniform size and shape and without substantial waste of expensive Ag.sup.+ solution. Flow control valves for controlling the flow rates of Ag.sup.+ and X.sup.- solutions are controlled according to a predetermined flow rate or pAg potential program and using output signals of respective flow meters or a pAg potentiometer. The flow control valves are motor-controlled flow control valves for which the rate of change of flow rate with valve stroke is small and linear.

Abstract: The invention is generally accomplished by forming a silver halide emulsion and during precipitation adding iridium and selenium in an amount effective to decrease reciprocity failure with substantially no decrease in speed. In a preferred form, a photographic element is formed comprising of bromoiodide emulsion having about 3 to about 88 nanograms of iridium per square meter of silver halide grain surface area and about 42 to about 487 nanograms of selenium per square meter of silver halide grain surface area. It is also preferred that the iridium and selenium be added at a point after the precipitation has proceeeded to a point wherein at least half of the silver to be added is present.

Abstract: A silver halide photographic material comprising at least one silver halide emulsion layer on a support, wherein the latent image distribution of silver halide grains contained in the at least one emulsion layer has at least one peak value within the grains, the location of the peak value is at a depth of less than 0.01 .mu.m from the surface of the grains, and the average silver iodide content of the grains is about 15 mol % or less.

Abstract: A silver halide photographic material, which comprises a support having thereon at least one silver halide emulsion layer, the silver halide emulsion layer containing light-sensitive silver halide grains having a structure such that cores of the respective grains have a completely uniform halide distribution and that shells with a higher silver chloride content than the cores are deposited outside the cores with no projections.

Abstract: There is disclosed a silver halide photographic light-sensitive material comprising a support and provided thereon, at least one silver halide light-sensitive layer spectrally sensitized by adding a spectral sensitizing dye during at least one process selected from a grain formation process, a physical reopening process and a desalting process, wherein said light-sensitive material contains at least one selected from the compounds represented by following Formula A: ##STR1## wherein R.sub.1 represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group, an alkoxy group, an aryl group, a heterocyclic group, a carbamoyl group, a thiocarbamoyl group, and a sulfamoyl group; R.sub.2 and R.sub.3 represent independently a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an aryl group, a cyano group, an alkylthio group, an arylthio group, an alkylsulfoxide group, an alkylsulfonyl group, and a heterocyclic group, provided that R.sub.2 and R.sub.

Abstract: A process is disclosed of preparing a photographic emulsion containing tabular silver halide grains exhibiting a reduced degree of total grain dispersity. After forming a population of silver halide grain nuclei containing parallel twin planes, ripening out a portion of the silver haide grain nuclei. The silver halide grain nuclei containing parallel twin planes remaining are then grown to form tabular silver halide grains. The total grain dispersity of the emulsion is reduced by incorporating bromide ion in the dispersing medium prior to forming the silver halide grain nuclei and, at the time parallel twin planes are formed in the silver halide grain nuclei, a polyalkylene oxide block copolymer surfactant containing at least three terminal hydrophilic alkylene oxide block units each linked through a lipophilic alkylene oxide block linking unit accounting for at least 4 percent of the molecular weight of the copolymer.