Abstract:
The invention provides a multilayered color photographic element and associated image forming process wherein the element comprises a support having coated thereon photographic silver halide emulsion layers said layers including at least two blue sensitive layers, the blue sensitive layers being the emulsion layers farthest from the support, wherein 
     the first of said blue sensitive layers is the most sensitive blue layer and is the emulsion layer farthest from the support, the first blue sensitive layer being extremely starved of dye-forming coupler, the second blue sensitive layer being contiguous said first blue sensitive layer.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. application Ser. No. 08/003,178 filed Jan. 12, 1993 now abandoned which is in turn a continuation of U.S. application Ser. No. 07/870,137 filed Apr. 16, 1992, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to a photographic material having multiple color layers comprising a unit of at least three green sensitive silver halide emulsion layers containing at least one magenta image dye-forming coupler which is also a bleach accelerating coupler. 
     Color photographic materials comprising multiple layers containing photographic couplers are well known. Typical photographic materials are described in U.S. Pat. Nos. 4,145,219; 4,724,198; 4,184,876; 4,186,016 and 4,724,198. 
     Prior photographic materials have exhibited problems with exposure reciprocity, speed, retained silver, color reproduction and neutral gray scale, flesh tone reproduction and image structure. 
     Various ways have been recognized in the photographic art for improving these problems. That is, for example, granularity can be improved but often it can be at the expense of another property such as speed. Or flesh tone color reproduction can be improved but neutral gray scale can be adversely affected. Thus, there is a great need for a photographic material which enables improvement in these properties without serious adverse affects. 
     U.S. Pat. No. 2,376,217 suggests that one way of avoiding the problems associated with the desensitization of emulsion layers due to the effects of the types of couplers in use in 1945 is to place a sensitized layer adjacent to the layer in question which is free of coupler. This will provide a layer which will not be adversely desensitized by the presence of coupler. The yellow couplers and the emulsions used today are not subject to desensitization problems, and thus, since this concern no longer exists, there would be no motivation to provide such a coupler-free layer in conjunction with today&#39;s couplers and emulsions. 
     SUMMARY OF THE INVENTION 
     The invention provides a multilayered color photographic element and associated image forming process wherein the element comprises a support having coated thereon photographic silver halide emulsion layers said layers including at least two blue sensitive layers, the blue sensitive layers being the emulsion layers farthest from the support, wherein 
     the first of said blue sensitive layers is the most sensitive blue layer and is the emulsion layer farthest from the support, the first blue sensitive layer being extremely starved of dye-forming coupler, the second blue sensitive layer being contiguous said first blue sensitive layer. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The first green sensitive layer is suitably comprised of at least one magenta image dye-forming coupler (A), a timed development inhibitor releasing coupler, and preferably a non-timed development inhibitor releasing coupler. The second layer is comprised of at least one first magenta image dye-forming coupler, (A), preferably at least one second magenta image dye-forming coupler, a development inhibitor releasing coupler and preferably a cyan dye-forming coupler. The third layer is comprised of at least one magenta image dye-forming coupler which is also a bleach accelerating releasing coupler. Further, the third layer contains a development inhibitor releasing coupler. 
     A typical photographic element in accordance with the invention comprises the following layer order: 
     
         ______________________________________OVERCOATUVMOST SENSITIVE BLUE OR FAST YELLOWLEAST SENSITIVE BLUE OR SLOW YELLOWINTERLAYERMOST SENSITIVE GREEN OR FAST MAGENTAMID SENSITIVE GREEN OR MID MAGENTALEAST SENSITIVE GREEN OR SLOW MAGENTAINTERLAYERMOST SENSITIVE RED OR FAST CYANLEAST SENSITIVE RED OR SLOW CYANINTERLAYERANTIHALATION LAYERSUPPORT______________________________________ 
    
     The overcoat layer can be comprised of components known in the photographic art for overcoat layers including UV absorbers, matting agents, surfactants, and like. A UV layer can also be used which contains similar materials. UV absorbing dyes useful in this layer and the antihalation layer have the structure: ##STR1## This layer, for example, also can contain dyes which can help in adjusting the photographic sensitivity of the element. Such dyes can be a green filter dye. A suitable green filter dye has the structure ##STR2## 
     A suitable red filter dye has the structure ##STR3## 
     Other dyes that may be used include washout dyes of the type referred to herein and filter dyes that decolorize during the photographic process. 
     Image Dye Forming Couplers 
     The image dye-forming couplers in the blue-sensitive, green-sensitive and red sensitive layers as described can be any of the image dye-forming couplers known in the photographic art for such layers for forming yellow, magenta and cyan dye images. Such couplers can comprise a coupler moiety (COUP) known in the art and as described. Combinations of the image dye-forming couplers can be useful in the described photographic silver halide emulsion layers. 
     Couplers that are yellow dye forming couplers are typically acylacetamides, such as benzoylacetanilides and pivalylacetanilides. Such couplers are described in such representative patents and publications as: U.S. Pat. Nos. 2,875,057; 2,407,210; 3,265,506; 2,298,443; 3,048,194; 4,022,620; 4,443,536; 3,447,928 and &#34;Farbkuppler: Eine Literaturbersicht&#34;, published in Agfa Mitteilungen, Band III, pages 112-126 (1961). 
     The couplers that are cyan image dye-forming couplers (C) are typically phenols or naphthols, such as described in the photographic art for forming cyan dyes upon oxidative coupling. 
     Examples of such couplers (C) that form cyan dyes are typically phenols and naphthols that are described in such representative patents and publications as: U.S. Pat. Nos. 2,772,162; 3,772,002; 4,526,864; 4,500,635; 4,254,212; 4,296,200; 4,457,559; 2,895,826; 3,002,936; 3,002,836; 3,034,892; 2,474,293; 2,423,730; 2,367,531; 3,041,236; 4,443,536; 4,124,396; 4,775,616; 3,779,763; 4,333,999 and &#34;Farbkuppler: Eine Literaturbersicht&#34;, published in Agfa Mitteilungen, Band III, pages 156-175 (1961). 
     Examples of couplers (A) that form magenta dyes are typically pyrazolones, pyrazolotriazoles and benzimidazoles, such couplers are described in such representative patents and publications as U.S. Pat. Nos. 2,600,788; 2,369,489; 2,343,703; 2,311,082; 3,824,250; 3,615,502; 4,076,533; 3,152,896; 3,519,429; 3,062,653; 2,908,573; 4,540,654; 4,443,536; 3,935,015; 3,451,820; 4,080,211; 4,215,195; 4,518,687; 4,612,278; and European Applications 284,239; 284,240; 240,852; 177,765 and &#34;Farbkuppler: Eine Literaturbersicht&#34;, published in Agfa Mitteilungen, Band III, pages 126-156 (1961). 
     The photographic element may be processed to form a developed image in an exposed color photographic element by developing the element with a color developer. 
     Fast Yellow 
     The fast yellow layer is a coupler starved layer exhibiting extreme coupler starvation. As used herein by coupler starved is meant a condition in the layer in which there is less dye-forming coupler than is theoretically capable of reacting with all of the oxidized developing agent generated at maximum exposure. Extreme coupler starvation is evidenced by a layer having a weight ratio of dye forming coupler to photographic silver halide (expressed as silver) of less than 0.10. In an embodiment of the invention, the weight ratio of dye-forming coupler to photographic silver halide (expressed as silver) is not more than 0.10. More suitably, the ratio is less than 0.05 and even more suitably less than 0.03. The layer is preferably substantially free of an image dye-forming coupler. The term dye-forming coupler means any coupler which will react with oxidized developer to form a yellow image dye. The coupler may be termed an &#34;image dye-forming&#34; coupler if the coupler does not contain a coupling-off group which has a photographic function. Couplers other than image dye-forming couplers can be present in this layer and such couplers can include, for example, timed development couplers as noted or non-timed DIR couplers and color correcting couplers. These other couplers are typically used at concentrations known in the photographic art and usually produce yellow dye typically not more than about 3% of the total density of the yellow record. 
     In the photographic element, the more blue sensitive layer or fast yellow layer contains a timed development inhibitor releasing coupler (DIR). Suitable timed DIR couplers used in the fast yellow layer comprise a DIR coupler (E) that is capable of releasing a mercapto-tetrazole development inhibitor comprising a substituent: 
     
         --X--COOR 
    
     characterized in that 
     X is alkylene of 1 to 3 carbon atoms and R is alkyl of 1 to 4 carbon atoms, and the sum of the carbon atoms X and R is 5 or less. The DIR coupler is typically a pivalylacetanilide coupler, such as described in U.S. Pat. No. 4,782,012. 
     The timed DIR coupler can be any timed DIR coupler useful in the photographic art which will provide a timed development inhibitor release. 
     That is, a development inhibitor releasing coupler containing at least one timing group (T) that enables timing of release of the development inhibitor group can be any development inhibitor releasing coupler containing at least one timing group known in the photographic art. The development inhibitor releasing coupler containing at least one timing group is represented by the formula: ##STR4## characterized in that COUP is a coupler moiety, as described, typically a cyan, magenta or yellow dye-forming coupler moiety; 
     T and T 1  individually are timing groups, typically a timing group as described in U.S. Pat. Nos. 4,248,962 and 4,409,232; 
     n is O or 1; and 
     Q 1  is a releasable development inhibitor group known in the photographic art. Q 1  can be selected from the INH group as described. 
     A preferred coupler of this type is described in U.S. Pat. No. 4,248,962. 
     Preferred timed DIR couplers of this type are: ##STR5## 
     Highly suitable timed DIR couplers have the structure: ##STR6## Color from the fast yellow layer is produced mostly as a result of oxidized developer formed in the fast yellow layer migrating to the adjacent slow yellow layer and reacting to form yellow dye. 
     Other couplers that are development inhibitor releasing couplers as described include those described in for example U.S. Pat. Nos. 4,248,962; 3,227,554; 3,384,657; 3,615,506; 3,617,291; 3,733,201; and U.K. 1,450,479. Preferred development inhibitors are heterocyclic compounds, such as mercaptotetrazoles, mercaptotriazoles, mercaptooxadiazoles, selenotetrazoles, mercaptobenzothiazoles, selenobenzothiazoles, mercaptobenzoxazoles, selenobenzoxazoles, mercaptobenzimidazoles, selenobenzimidazoles, benzotriazoles, benzodiazoles and 1,2,4-triazoles, tetrazoles, and imidazoles. 
     Slow Yellow Layer 
     In the photographic element, the less blue sensitive layer or slow yellow layer contains a yellow image dye-forming coupler. Such yellow image dye-forming coupler can be any yellow dye-forming coupler useful in the photographic art. 
     Couplers that are yellow image dye-forming couplers are typically acylacetamides, such as benzoylacetanilides and pivalylacetanilides, such as described in the photographic art for forming yellow dyes upon oxidative coupling. 
     The yellow dye-forming coupler in the slow yellow layer is typically a pivalylacetanilide coupler containing a hydantoin coupling-off group. Such a coupler is illustrated by the formula: ##STR7## characterized in that R 2  is chlorine, bromine or alkoxy; 
     R 3  is a ballast group, such as a sulfonamide or carboxamide ballast group; and 
     Z is a coupling-off group, preferably a hydantoin coupling off group as described in U.S. Pat. No. 4,022,620. 
     Yellow dye-forming couplers suitable for the slow yellow or less sensitive blue layer are: ##STR8## A preferred yellow dye-forming coupler for the slow yellow layer has the structure: ##STR9## 
     Timed or non-timed DIR couplers as noted with respect to the fast yellow layer may also be used in the slow yellow lower. 
     Interlayer 
     In the photographic element a yellow filter layer is provided between the slow yellow and the fast magenta. This layer can comprise Carey Lea silver (CLS), bleach accelerating silver salts, any oxidized developer scavenger known in the photographic art, such as described in U.S. Pat. No. 4,923,787, and a dye to enable improved image sharpness or to tailor photographic sensitivity of the element. A preferred oxidized developer scavenger is: ##STR10## 
     Other oxidized developer scavenger useful in the invention include: ##STR11## 
     When finely divided silver such as Carey Lea silver is used in the yellow filter layer and the photographic element contains a BARC, then preferably an interlayer is provided between the yellow filter and any other layer that contains a dye forming coupler. If a bleach accelerating silver salt (BASS) is used, preferably in the yellow filter layer, then it is preferred to provide an interlayer to isolate the BASS containing layer from the remainder of the film. This interlayer may contain the oxidized developer scavenger noted above. Further, the interlayer may be contiguous with the yellow filter layer and may be disposed on both sides of the yellow filter layer. Representative bleach accelerating silver salts are disclosed in U.S. Pat. Nos. 4,865,965; 4,923,784; 4,163,669. The bleach accelerating silver salts can comprise silver salts of mercapto proprionic acid. 
     BARC and BASS compounds may be used in combination in the element. 
     Other representative bleach accelerating silver salts which may be used in the interlayer are structurally shown as follows: ##STR12## 
     Instead of using finely divided silver in the yellow filter layer, filter dyes may be used. When filter dyes are used, then the interlayer contiguous or adjacent the yellow filter layer may be omitted. Oxidized developer scavenger as referred to above may be used in the yellow filter layer with the filter dye. Examples of filter dyes such as washout or decolorizing dyes useful in the present invention are described in U.S. Pat. No. 4,923,788 incorporated herein by reference. Such filter dyes have the formula: ##STR13## characterized in that R is substituted or unsubstituted alkyl or aryl, X is an electron withdrawing group, R&#39; is substituted or unsubstituted aryl or a substituted or unsubstituted aromatic heterocyclic nucleus, and L, L&#39;, and L&#34; are each independently a substituted or unsubstituted methine group. 
     Preferred alkyl groups include alkyl of from 1 to 20 carbon atoms, including straight chain alkyls such as methyl, ethyl, propyl, butyl, pentyl, decyl, dodecyl, and so on, branched alkyl groups such as isopropyl, isobutyl, t-butyl, and the like. These alkyl groups may be substituted with any of a number of known substituents, such as sulfo, sulfato, sulfonamide, amido, amino, carboxyl, halogen, alkoxy, hydroxy, phenyl, and the like. The substituents may be located essentially anywhere on the alkyl group. The possible substituents are not limited to those exemplified, and one skilled in the art could easily choose from a number of substituted alkyl groups that would provide useful compounds according to the formula. 
     Preferred aryl groups for R include aryl of from 6 to 10 carbon atoms (e.g., phenyl, naphthyl), which may be substituted. Useful substituents for the aryl group include any of a number of known substituents for aryl groups, such as sulfo, sulfato, sulfonamido (e.g., butane-sulfonamido), amido, amino, carboxyl, halogen, alkoxy, hydroxy, acyl, phenyl, alkyl, and the like. 
     The filter dyes may be used in combination with the finely divided silver. 
     It will be appreciated that permanent yellow filter dyes can be used instead of CLS or washout-filter dyes, such permanent dyes, for example, have structures: ##STR14## 
     A decolorizing microcrystalline dye useful in the invention has the structure: ##STR15## 
     Fast Magenta Layer 
     The most green sensitive layer or fast magenta layer comprises a magenta image dye-forming coupler (A), a timed development inhibitor releasing coupler (DIR), preferably a non-timed DIR coupler and preferably a masking coupler. 
     The magenta image dye-forming coupler (A) can be any image forming coupler dye useful in the photographic art. 
     A typical magenta image dye-forming coupler is a pyrazolotriazole. Suitable couplers that form magenta dyes include: ##STR16## 
     A preferred magenta image dye-forming coupler has the structure: ##STR17## 
     Suitable timed DIR couplers comprise a DIR coupler (E) that is capable of releasing a mercaptotetrazole development inhibitor as noted with respect to the fast yellow layer. 
     The masking coupler can be any masking coupler suitable for use in a photographic element. Preferably the masking coupler has structure: ##STR18## 
     The masking coupler can be placed in any of the three magenta imaging layers. 
     The non-timed DIR coupler (B) used in the fast magenta layer can be any non-timed DIR coupler known in the photographic art. Examples of such non-timed DIR couplers are disclosed in U.S. Pat. No. 3,227,554 incorporated herein by reference. 
     Preferred non-timed DIR couplers (B) have the structure: ##STR19## 
     Mid Magenta Layer 
     The mid-magenta or mid green sensitive layer comprises at least one first magenta image dye-forming coupler, and preferably at least one second magenta image dye-forming coupler, preferably a non-timed DIR coupler and preferably a cyan dye-forming coupler (C). 
     The first magenta image dye-forming coupler can be coupler (A) referred to in the fast magenta layer. 
     The second magenta image dye-forming coupler can be any image forming coupler dye useful in the photographic art and can include the magenta image dye-forming coupler (A) referred to in the fast magenta layer. 
     A typical magenta image dye-forming coupler is a pyrazolotriazole. A preferred second image dye-forming coupler is coupler (34). 
     Coupler (14) is another preferred second magenta image dye forming coupler. 
     Suitable non-timed DIR couplers useful in the mid magenta layer are as described for the fast magenta layer and can be preferred coupler (B), for example. 
     The described cyan image dye-forming coupler (C) can be any cyan image dye-forming coupler known in the photographic art with its use in the magenta record herein referred to as a color correcting coupler. The cyan image dye-forming coupler is typically a phenol or naphthol coupler described in such representative patents and publications as noted herein. 
     Preferred cyan image dye-forming couplers (C) for the mid magenta layer have the structures: ##STR20## Coupler (21) may also be used in the mid magenta layer. 
     Slow Magenta Layer 
     The slow magenta layer contains at least one magenta image dye-forming coupler which is preferably a bleach accelerating releasing coupler (BARC). The slow magenta layer also contains a development inhibiting releasing coupler (DIR) preferably a non-timed DIR. 
     The bleach accelerator releasing coupler can be any bleach accelerator releasing coupler known in the photographic art. Combinations of such couplers are also useful. The bleach accelerator releasing coupler can be represented by the formula: ##STR21## characterized in that COUP is a coupler moiety as described, typically a cyan, magenta or yellow dye-forming coupler moiety; 
     T 2  is a timing group known in the photographic art, typically a timing group as described in U.S. Pat. Nos. 4,248,962 and 4,409,323, the disclosures of which are incorporated herein by reference; 
     m is 0 or 1; 
     R 3  is an alkylene group, especially a branched or straight chain alkylene group, containing 1 to 8 carbon atoms; and 
     R 4  is a water-solubilizing group, preferably a carboxy group. 
     Typical bleach accelerator releasing couplers are described in, for example, European Patent 193,389. 
     A suitable bleach accelerator releasing coupler has the structure: ##STR22## 
     A preferred bleach accelerator releasing coupler has the structure: ##STR23## 
     Combinations of bleach accelerating couplers may be used the bleach accelerating coupler can be used in the other imaging layer including the magenta imaging layers. 
     The DIR coupler for the slow magenta layer can be the same coupler (B) used for the fast magenta or mid magenta layer. 
     An interlayer may be added between the fast and mid or mid and slow magenta layers. 
     Cyan dye-forming coupler (C) may be used in the slow magenta layer as in the mid magenta layer. 
     Interlayer 
     The interlayer between the slow magenta and the fast cyan layers can contain an oxidized developer scavenger or dyes that are added to adjust photographic speed or density of the film. A preferred oxidized developer scavenger is as described for the yellow filter layer. The dyes can be the same as for the UV layer and an additional dye which is useful in this layer can include coupler (11). 
     Fast Cyan Layer 
     The fast cyan or most red sensitive layer contains a cyan image dye-forming coupler (C), a first non-timed DIR coupler, preferably a second non-timed DIR coupler, a masking coupler and a yellow image dye-forming correcting coupler. 
     The cyan image dye-forming coupler (C) useful in the fast cyan layer is as described for the mid magenta layer. The preferred cyan image dye-forming coupler is the same preferred coupler (C) as for the mid magenta layer. 
     The first and second non-timed DIR couplers in the fast cyan layer or most red sensitive layer can be any development inhibitor releasing coupler known in the photographic art. Typical DIR couplers are described in, for example, U.S. Pat. Nos. 3,227,554; 3,384,657; 3,615,506; 3,617,291; 3,733,201 and U.K. 1,450,479. Such DIR couplers upon oxidative coupling preferably do not contain a group that times or delays release of the development inhibitor group. The DIR coupler is typically represented by the formula: 
     
         COUP-INH 
    
     characterized in that COUP is a coupler moiety and INH is a releasable development inhibitor group that is bonded to the coupler moiety at a coupling position. The coupler moiety COUP can be any coupler moiety that is capable of releasing the INH group upon oxidative coupling. 
     The coupler moiety (COUP) is, for example, a cyan, magenta or yellow forming coupler known in the photographic art. The COUP can be ballasted with a ballast group known in the photographic art. The COUP can also be monomeric, or it can form part of a dimeric, oligomeric or polymeric coupler, in which case more than one inhibitor group can be contained in the DIR coupler. 
     The releasable development inhibitor group (INH) can be any development inhibitor group known in the photographic art. Illustrative INH groups are mercaptotetrazoles, selenotetrazoles, mercaptobenzothiazoles, selenobenzothiazoles, mercaptobenzimidazoles, selenobenzimidazoles, mercaptobenzoxazoles, selenobenzoxazoles, mercaptooxadiazoles, mercaptothiadiazoles, benzotriazoles, and benzodiazoles. Preferred inhibitor groups are mercaptotetrazoles and benzotriazoles. Particularly preferred inhibitor groups are described in for example U.S. Pat. Nos. 4,477,563 and 4,782,012. 
     Preferred DIR couplers within COUP-INH are coupler (37) and: ##STR24## 
     Timed DIR couplers which may be used in this layer have the structures of couplers (24), (27) and (28) and ##STR25## 
     The second non-timed DIR coupler which may be used in the fast cyan layer has the structure. ##STR26## 
     A further second non-timed DIR coupler which may be used in the fast cyan layer has the structure of coupler (37). 
     The masking coupler in the most red sensitive layer is typically a cyan dye-forming masking coupler, such as a naphthol cyan dye-forming masking coupler. 
     A preferred cyan dye-forming masking coupler for the cyan dye-forming layers of the photographic element is: ##STR27## 
     The yellow image dye-forming coupler can be any such coupler useful in the photographic art with its use in the cyan record sometimes referred to as a color correcting coupler. Couplers that are yellow dye forming couplers are typically acylacetamides, such as benzoylacetanilides and pivalylacetanilides as noted. Such couplers are described in such representative patents and publications as noted earlier. 
     The yellow dye-forming coupler is preferably a pivalylacetanilide comprising a phenoxy coupling off group. Such yellow dye-forming couplers have the same structures as used in the slow yellow layer and the preferred coupler is coupler (6). 
     Slow Cyan Layer 
     The slow cyan or less sensitive red layer contains a cyan image dye-forming coupler (C), a timed DIR coupler or development inhibitor anchimeric releasing coupler (DIAR), a non-timed DIR coupler, and a yellow image dye-forming correcting coupler. 
     The cyan image dye-forming coupler can be the same cyan image dye-forming coupler (C) as used in the fast cyan layer. Also, the yellow image dye-forming correcting coupler can be the same yellow image dye-forming coupler as used in the fast cyan layer. 
     An illustrative development inhibitor releasing coupler containing at least one timing group (T) that enables timing of release of the development inhibitor group preferably has the structure of coupler (5). 
     The non-timed DIR coupler can be the same as for the fast cyan layer. 
     Interlayer 
     An interlayer is provided between the slow cyan layer and the antihalation layer. The interlayer can contain an oxidized developer scavenger. A preferred oxidized developer scavenger is as described for the yellow filter layer. This interlayer solves a problem of increased fog resulting from interaction of bleach accelerating releasing coupler with silver in the antihalation layer. Thus, providing this interlayer between a BARC containing layer anywhere in the element and the antihalation layer so as to isolate the antihalation layer from layers containing dye-forming couplers, permits the advantageous use of a BARC for good silver bleaching without increasing fog or Dmin with respect to the antihalation layer, for example, while maintaining desired acutance. 
     Antihalation Layer 
     The antihalation layer can contain very fine gray or black silver filamentary or colloidal silver, e.g. CLS, and preferably a UV absorbing dyes, gelatin and colored dyes such as coupler (11) to provide density to the film. 
     While the antihalation layer has been described with respect to silver, other materials can be substituted for or used in conjunction with the silver. That is, instead of using finely divided silver in the antihalation layer, filter dyes such as washout-dyes or decolorizing dyes of the type referred to herein may be used. When filter dyes are used in the antihalation layer, the interlayer adjacent the antihalation layer may be omitted. Oxidized developer scavenger may be omitted from the antihalation layer when filter dyes are used. Examples of dyes which may be used in the antihalation layer are described in U.S. Pat. No. 4,923,788 as noted earlier. 
     Bleach accelerating silver salts as described with respect to the yellow filter layer may be used in the antihalation layer in conjunction with the finely divided silver. When bleach accelerating silver salts are used in antihalation it is preferred to use the interlayer over the antihalation layer as noted to minimize fog or Dmin. 
     In the following discussion of suitable materials for use in the emulsions and elements of this invention, reference will be made to Research Disclosure, December 1989, Item 308119, published by Kenneth Mason Publications, Ltd., Dudley Annex, 12a North Street, Emsworth, Hampshire. P010 7DQ, ENGLAND, the disclosures of which are incorporated herein by reference. This publication will be identified hereafter by the term &#34;Research Disclosure&#34;. 
     The silver halide emulsions employed in the elements of this invention can be negative-working. Suitable emulsions and their preparation are described in Research Disclosure Sections I and II and the publications cited therein. Suitable vehicles for the emulsion layers and other layers of elements of this invention are described in Research Disclosure Section IX and the publications cited therein. 
     In addition to the couplers generally described above, the elements of the invention can include additional couplers as described in Research Disclosure Section VII, paragraphs D, E, F and G and the publications cited therein. These couplers can be incorporated in the elements and emulsions as described in Research Disclosure Section VII, paragraph C and the publications cited therein. 
     The photographic elements of this invention or individual layers thereof, can contain brighteners (see Research Disclosure Section V), antifoggants and stabilizers (See Research Disclosure Section VI), antistain agents and image dye stabilizers (see Research Disclosure Section VII, paragraphs I and J), light absorbing and scattering materials (see Research Disclosure Section VIII), hardeners (see Research Disclosure Section IX), plasticizers and lubricants (See Research Disclosure Section XII), antistatic agents (see Research Disclosure Section XIII), matting agents (see Research Disclosure Section XVI) development modifiers (see Research Disclosure Section XXI) surfactants and coating aids. 
     The photographic elements can be coated on a variety of supports as described in Research Disclosure Section XVII and the references described therein. 
     Photographic elements can be exposed to actinic radiation, typically in the visible region of the spectrum, to form a latent image as described in Research Disclosure Section XVIII and then processed to form a visible dye image as described in Research Disclosure Section XIX. Processing to form a visible dye image includes the step of contacting the element with a color developing agent to reduce developable silver halide and oxidize the color developing agent. Oxidized color developing agent in turn reacts with the coupler to yield a dye. 
     With negative working silver halide, the processing step described above gives a negative image. 
     Development is followed by the conventional steps of bleaching, fixing, or bleach-fixing, to remove silver and silver halide, washing and drying. 
    
    
     EXAMPLE I 
     A three color photographic film was prepared as follows using conventional surfactants, antifoggants and the materials indicated. After providing a developable image and then processing in accordance with the Kodak C-41 process (British Journal of Photographic, pp. 196-198 (1988)) excellent results e.g. improved color, sharpness, granularity and neutral scale, were obtained and manufacturing cost savings were realized. All silver halide emulsions were stabilized with 1.75 gm 4-hydroxy-6-methyl-1,3,3a,7-tetraazaindene per mole of silver. All silver halide emulsions were sensitized with the appropriate spectral red, green and blue sensitizing dyes. 
     
         ______________________________________Support    mg/m.sup.2              mg/ft.sup.2______________________________________Layer 1Antihalation      215     20        Black colloidal silverLayer      91      8.5       UV absorbing dye                        coupler (1)      91      8.5       UV absorbing dye                        coupler (2)      14.3    13        Blue filter dye (11)      2422    225       GelatinLayer 2Interlayer 54      5.0       D-Ox scavenging                        coupler (3)      861     80.0      GelatinLayer 3Least Red  915     85        Red sensitized silverSensitive                    iodobromide emulsionLayer                        (4.5% iodide, tabular                        grains with average                        grain diameter 1.1                        micron and average                        grain thickness 0.1                        micron),      1238    115       Red sensitized silver                        iodobromide emulsion                        (0.5% iodide, cubic                        grains with average                        edge length 0.21                        microns)      603     56        Cyan dye forming image                        coupler (4)      36      3.3       Cyan dye forming                        development inhibitor                        release (DIR) coupler                        (5)      86      8.0       Yellow dye-forming                        image coupler (6)      3078    286       GelatinLayer 4Most Red-  1291    120       Red sensitized silverSensitive                    iodobromide emulsionLayer                        (3% iodide, octahedral                        grains with average                        grain diameter 0.90                        micron)      54      5.0       Cyan dye-forming image                        coupler (4)      32.3    3         Cyan dye-forming                        masking coupler (7)      50      4.6       Cyan dye-forming DIR                        coupler (9)      11      1.0       Yellow dye-forming                        image coupler (6)      2368    220       Gelatin      4.3     0.4       Cyan dye-forming DIR                        coupler (8)Layer 5Interlayer 129     12        Oxidized development                        scavenger coupler (3)      861     80        Gelatin      11      1         Green filter dye (10)      49      4         Blue filter dye (11)Layer 6Least Green-      124     15        Green sensitizedSensitive                    silver iodobromideLayer                        emulsion (3% iodide,                        tabular grains with                        average grain diameter                        0.8 micron, and                        average grain                        thickness 0.1 micron)      592     55.0      Green sensitized                        silver iodobromide                        emulsion (0.5% iodide,                        tabular gains with                        average grain diameter                        0.5 and average grain                        thickness 0.1 micron)      161     15.0      Magenta dye-forming                        image coupler that                        releases a bleach                        accelerating fragment                        (12)      12      1.1       Magenta dye-forming                        DIR coupler (13)      1507    140       GelatinLayer 7Mid Green- 969     90.0      Green sensitizedSensitive                    silver iodobromideLayer                        emulsion (3% iodide,                        tabular grains with                        average grain diameter                        0.8 micron and average                        grain thickness 0.1                        micron)      75.0    7.0       Magenta dye-forming                        image coupler (14)      54.0    5.0       Magenta dye-forming                        image coupler (15)      9.0     0.8       Magenta dye-forming                        DIR coupler (13)      11.0    1.0       Cyan dye forming,                        image coupler (4)      1238    115.0     GelatinLayer 8Most Green-      753.0   70.0      Green sensitizedSensitive                    silver iodobromideLayer                        emulsion (6% iodide,                        tabular grains with                        average grain diameter                        1.0 micron and average                        grain thickness 0.1                        micron)      22.0    2.0       Magenta dye-forming                        image coupler (15)      13.0    1.2       Magenta dye-forming                        DIR coupler (13)      65.0    6.0       Magenta dye-forming                        development masking                        coupler (16)      26.0    2.4       Yellow dye-forming DIR                        coupler (17)      969     90.0      GelatinLayer 9Interlayer 75.0    7.0       D-Ox scavenging                        coupler (3)      194.0   18.0      Developer bleachable                        yellow filter dye (18)      861.0   80.0      GelatinLayer 10Least Blue-      215.0   20.0      Blue sensitized silverSensitive                    iodobromide emulsionLayer                        (6% iodide, octahedral                        grains with average                        grain diameter of 0.65                        micron)      129.0   12.0      Blue sensitized silver                        iodobromide emulsion                        (5% iodide, octahedral                        grains with average                        grain diameter of 0.40                        micron)      258.0   24.0      Blue sensitized silver                        iodobromide emulsion                        (5% iodide, octahedral                        grains with average                        grain diameter of 0.23                        micron)      1100.   97.0      Yellow dye-forming                        image coupler (19)      1420    132.0     GelatinLayer 11Most Blue- 377.0   35.0      Blue sensitized silverSensitive                    iodobromideLayer                        emulsion (6% iodide,                        octahedral grains with                        average grain diameter                        of 1.0 micron)      11.0    1.0       Yellow dye-forming DIR                        coupler (17)      1076    100.0     GelatinLayer 12First      215.0   20.0      Unsensitized silverProtective                   bromide LippmanLayer                        emulsion (0.04                        microns)      108.0   10.0      UV absorbing dye (1)      129.0   12.0      UV absorbing dye (2)      753.0   70.0      Tricresyl phosphate      1345    125.0     Gelatin      40      0.4       Green absorbing dye                        (10)      20      0.2       Red absorbing dye (20)Layer 13Second     44.0    4.1       Matte polyvinyltolueneProtective                   beadsLayer      883.0   82.0      Gelatin______________________________________ 
    
     The example will provide improvement in one or more photographic properties such as reciprocity, granularity, speed, retained silver, color reproduction and neutral gray scale, flesh tone reproduction and image structure and also provides cost savings due to reduction in the coupler required. 
     EXAMPLE II 
     A three color photographic film was prepared using conventional surfactants, antifoggants, image couplers, development inhibitor releasing couplers, masking couplers, bleach accelerator releasing couplers, silver iodobromide emulsions, and sensitizing dyes. A conventional coating structure was also employed; i.e. overcoat/ultraviolet light absorbing layer/blue light sensitive layer of the highest sensitivity/blue light sensitive layer of lowest sensitivity/blue light absorbing layer/green light sensitive layer of highest sensitivity/green light sensitive layer of lowest sensitivity/interlayer/red light sensitive layer of highest sensitivity/red light sensitive layer of lowest sensitivity/antihalation layer/acetate support. 
     Levels of silver, gelatin, and coupler were varied in the most blue light sensitive layer, hereafter referred to as the &#34;fast yellow&#34; layer, and the least blue light sensitive, hereafter referred to as the &#34;slow yellow&#34; layer. It is known that increasing gelatin in the fast yellow layer will affect optical characteristics. As gelatin increases, optical scattering increases (The Theory of the Photographic Process, James, 4th edition, 598-607). Increasing gelatin in the fast yellow layer will also affect development characteristics. Another name for this effect is &#34;coupler borrowing&#34;, where oxidized developer created in the fast yellow layer wanders down and reacts with coupler in the slow yellow layer. When coupler borrowing occurs, higher gamma results in the low exposure area of the sensitometric curve. 
     The following experiments illustrate the problem and several known solutions to high gamma resulting from coupler borrowing. 
     
         ______________________________________Variation  Weight % C/S                 FY gel level (g/m2)                              FY Emulsion______________________________________EXP1A comparative      38.8       1.03         EMUL1EXP1B comparative      38.8       1.03         EMUL2EXP2A comparative      35         0.65         EMUL3EXP2B comparative      35         1.29         EMUL3EXP2C comparative      35         1.94         EMUL3EXP3A comparative      27.5       1.55         EMUL3EXP3B invention      7.5        1.55         EMUL3EXP4A comparative      30         1.55         EMUL3EXP4B invention      10         1.55         EMUL3EXP4C invention      0          1.55         EMUL3______________________________________ 
    
     Terms in the table are defined as follows: 
     C/S=weight of Coupler coated per unit area divided by the weight of Silver coated per unit area contained in the blue light sensitive layer of highest sensitivity. `Coupler` here refers to total image dye forming coupler plus image dye forming development inhibitor releasing coupler. 
     FY=blue light sensitive layer of highest sensitivity. 
     SY=blue light sensitive layer of lowest sensitivity. 
     EMUL1=an octahedral silver bromoiodide emulsion, with a grain diameter of 0.9 microns, containing 1.25% iodide in a core region and 1.75% iodide in a subsurface region. 
     EMUL2=a polydisperse silver bromoiodide emulsion of non-distinct morphology, with an average grain diameter of 0.9 microns, containing 6.3% bulk iodide, with a precipitation scheme incorporating a run salt with a thiocyanate digest. 
     EMUL3=an octahedral silver bromoiodide emulsion, with a grain diameter of 0.9 microns, containing 2.5% iodide in a core region and 3.5% iodide in a subsurface region. 
     The results from these experiments are summarized in the table which follows: 
     
         ______________________________________Variation      under gamma                     granularity______________________________________EXP1A comparative          0.61       0.024EXP1B comparative          0.73       0.019EXP2A comparative          0.95       0.022EXP2B comparative          0.79       0.019EXP2C comparative          0.73       0.019EXP3A comparative          0.69       0.019EXP3B invention          0.54       0.018EXP4A comparative          0.77       0.018EXP4B invention          0.60       0.018EXP4C invention          0.59       0.018______________________________________ 
    
     Terms in the table are defined as follows: 
     under gamma=gamma in the under exposure region of the sensitometric curve, measured from a log exposure located 0.15 density above minimum density, to a log exposure which is 0.40 log exposure units more exposed. The &#34;aim&#34; low gamma in all of these experiments was 0.55 
     granularity=average root mean square of density fluctuation measured with a 48 μm aperture, measured from a log exposure located 0.40 log exposure units more exposed than 0.15 density above minimum density, to a log exposure which is 0.80 log exposure units more exposed than 0.15 density above minimum density. 
     The goal of this series of experiments was to obtain a film with aim gamma in the under exposure region of the curve (gamma=0.55), while yielding acceptable granularity and minimizing the thickness of the coated structure in order to minimize optical degradation from light scatter. 
     From experiment 1 (EXP1A, EXP1B), it is evident that an emulsion which has inherently low gamma can be used to obtain lower gamma in the under exposure region of the sensitometric curve, but this will result in undesirable granularity. In this case, the run salt thiocyanate digest emulsion (EMUL1) yields lower gamma but granularity which is 26% higher than that obtained from the higher gamma core/shell octahedra. 
     From experiment 2 (EXP2A, EXP2B, EXP2C), it is evident that lower gamma in the under exposure region of the sensitometric curve can be obtained by incorporating higher levels of gelatin in the FY layer. This is due to a decrease of coupler borrowing from the SY layer to the FY layer. This also results in a thickening of the coating structure, which will result in increased optical degradation of light to underlying layers. 
     From experiment 3 (EXP3A, EXP3B), the technique of extreme coupler starvation is employed to obtain close to aim gamma in the under exposure portion of the sensitometric curve, while utilizing the low granularity core/shell emulsion, and maintaining constant coating thickness. This is done by utilizing coupler borrowed from the slow layer for imaging from the fast layer. The only way to do this and maintain low gamma, low granularity, and minimize optical scatter is to incorporate extreme coupler starvation. 
     From experiment 4 (EXP4A, EXP4B, EXP4C), the technique of extreme coupler starvation is employed to obtain closer to aim gamma in the under exposure portion of the sensitometric curve, while utilizing the low granularity core/shell emulsion, and maintaining constant coating thickness. This is done by utilizing coupler borrowed from the slow layer for imaging from the fast layer. The only way to do this and maintain low gamma, low granularity, and minimize optical scatter is to incorporate extreme coupler starvation. 
     The invention has been described in detail with particular reference to particular embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.