A photographic element comprises at least one light-sensitive layer comprising a silver halide emulsion, wherein the silver halide content is less than or equal to 30% silver chloride, and a dye of formula (I) or formula (II): ##STR1## wherein the substituents are as defined in the specification. ##STR2## wherein the substituents are as defined in the specification.

FIELD OF THE INVENTION 
This relates to photographic element comprising a light-sensitive silver 
halide layer containing a sensitizing dye that minimizes fog, but retains 
high sensitivity. 
BACKGROUND OF THE INVENTION 
Conventional silver halide photography uses silver halide particles as the 
light sensitive elements. These particles are only sensitive to 
ultraviolet and blue radiation. In order to make the silver halide 
sensitive to other wavelengths of the visible and infrared spectrum, 
sensitizing dyes are adsorbed to the surface of the silver halide 
particles. In order to enhance the sensitivity of the particles they are 
treated with so-called chemical sensitizers, such as sulfur compounds and 
gold compounds. The process of adding chemical sensitizers and dyes is 
known as chemical and spectral sensitization. It can be done in discreet 
steps or simultaneously (dye-in-the-finish) sensitization. There is a 
constant need for ever more sensitive emulsions. In the process of pushing 
silver halide particles to greater sensitivity through the use of 
sensitizing agents, it is difficult to achieve high sensitivity to light 
without introducing "fog" centers. Fog is the unwanted development of 
crystals which have not been exposed to light. 
Fog is often controlled by the addition of emulsion stabilizers or 
antifoggants, but these materials must compete for the limited grain 
surface with all of the other addenda and dyes, limiting the total amount 
of addenda that can be used. It would be advantageous if a sensitizing dye 
also acted as an emulsion stabilizer and an antifoggant. This would allow 
higher dye coverage on the surface of the silver halide and less need for 
additional antifoggants and stabilizers. 
U.S. Pat. Nos. 3,930,860 and 3,933,507 describes dyes that are antifogging 
through the formation of silver complexes, i.e. merocyanines with 
thiocarbonyl groups. One example of a 5,6-dimethoxybenzothiazole 
merocyanine is given in the latter reference. U.S. Pat. No. 4,493,520 
generally alleges that certain spectral sensitizing dyes can also function 
as antifoggants or stabilizers. Reference is made to U.S. Pat. No. 
3,930,860, discussed above, and U.S. Pat. No. 2,131,038, which discloses 
quaternary salts containing the nucleus: 
##STR3## 
where Y=O, S or Se exert a stabilizing or anti-fogging effect. These 
compounds are only quaternary salts, not dyes. Therefore they compete for 
area on the surface of silver halide grains with the dye. With antifogging 
dyes less of these quaternary salts are needed. 
SUMMARY OF THE INVENTION 
We have found unexpectedly, that certain spectral sensitizing dyes do act 
as antifoggants. These dyes give lower levels of fresh fog, and also 
stabilize the emulsion toward changes as coatings of the emulsion age. 
One aspect of this invention is a photographic element comprising at least 
one light-sensitive layer comprising a silver halide emulsion, wherein the 
silver halide content is less than or equal to 30% silver chloride, and a 
dye of formula (I) or formula (II): 
##STR4## 
wherein: each L is a substituted or unsubstituted methine group, n is 0 or 
1; 
R.sub.1 and R.sub.2 are substituted or unsubstituted alkyl groups; 
V is a 4-methoxy or 6-methoxy group; 
W.sub.1 -W.sub.4 are independently hydrogen, alkyl, halogen, aryl, 
heteroaryl, alkylthio or alkoxy, with the proviso that no more than one of 
W.sub.1 -W.sub.4 is alkoxy or W.sub.2 and W.sub.3 or W.sub.3 and W.sub.4 
can be a fused ring; and 
X.sub.1 and X.sub.2 are independently S or Se; 
##STR5## 
wherein: each L' is a substituted or unsubstituted methine group, n' is 0 
or 1; 
R.sub.3 and R.sub.4 are substituted or unsubstituted alkyl groups; 
V.sub.1 is a 4-methoxy or 6-methoxy group; 
W.sub.5 -W.sub.8 are independently hydrogen, alkyl, halogen, aryl, 
heteroaryl, alkylthio or alkoxy, with the proviso that no more than one of 
W.sub.5 -W.sub.8 is alkoxy and if n' is 1, none of W.sub.5 -W.sub.8 is 
aryl, or W.sub.6 and W.sub.7 or W.sub.7 and W.sub.8 can be a fused ring; 
and 
X.sub.3 is S or Se. 
In certain embodiments of the invention the silver halide emulsion 
comprises at least one additional dye. 
ADVANTAGEOUS EFFECT OF THE INVENTION 
The invention provides a photographic element in which a silver halide 
emulsion layer contains a sensitizing dye that not only sensitizes the 
silver halide but also reduces fog. 
DETAILED DESCRIPTION OF THE INVENTION 
The photographic element of this invention comprises a photographic element 
comprising at least one light-sensitive layer comprising a silver halide 
emulsion, wherein the silver halide content is equal to or less than about 
30% silver chloride, and a dye of formula (I) or formula (II): 
##STR6## 
wherein: each L is a substituted or unsubstituted methine group, n is 0 or 
1; 
R.sub.1 and R.sub.2 are substituted or unsubstituted alkyl groups; 
V is a 4-methoxy or 6-methoxy group; 
W.sub.1 -W.sub.4 are independently hydrogen, alkyl, halogen, aryl, 
heteroaryl, alkylthio or alkoxy, with the proviso that no more than one of 
W.sub.1 -W.sub.4 is alkoxy or W.sub.2 and W.sub.3 or W.sub.3 and W.sub.4 
can be a fused ring; and 
X.sub.1 and X.sub.2 are independently S or Se; 
##STR7## 
wherein: each L' is a substituted or unsubstituted methine group, n' is 0 
or 1; 
R.sub.3 and R.sub.4 are substituted or unsubstituted alkyl groups; 
V.sub.1 is a 4-methoxy or 6-methoxy group; 
W.sub.5 -W.sub.8 are independently hydrogen, alkyl, halogen, aryl, 
heteroaryl, alkylthio or alkoxy, with the proviso that no more than one of 
W.sub.5 -W.sub.8 is alkoxy and if n' is 1, none of W.sub.5 -W.sub.8 is 
aryl, or W.sub.6 and W.sub.7 or W.sub.7 and W.sub.8 can be a fused ring; 
and 
X.sub.3 is S or Se. 
Illustrative dyes of formnula I are: 
##STR8## 
Preferred dyes of formula (II) are dyes in which n' is 1 and the center L' 
is substituted with an alkyl group, in particular an ethyl group. 
Illustrative dyes of formula II are: 
##STR9## 
The dyes of formula (I) can be prepared by synthetic techniques well-known 
in the art. Such techniques are illustrated, for example, in Hamer, 
Cyanine Dyes and Related Compounds, 1964 (publisher John Wiley, & Sons, 
New York, N.Y.) and James, The Theory of the Photographic Process 4th 
edition, 1977 (Eastman Kodak Company, Rochester N.Y.). The amount of 
sensitizing dye that is useful in the invention is preferably in the range 
of 0.1 to 4.0 millimoles per mole of silver halide and more preferably 
from 0.2 to 2.2 millimoles per mole of silver halide. Optimum dye 
concentrations can be determined by methods known in the art. 
The silver halide emulsion used in the photographic element of this 
invention can contain one or more additional sensitizing dyes. Among the 
sensitizing dyes that can be used include, for example, those disclosed in 
Research Disclosure, Sep. 1996, Number 389, Item 38957, Section V(A) the 
disclosure of which, including patent specifications listed therein, is 
incorporated herein by reference. 
Reference to a light sensitive layer or a light sensitive silver halide 
layer, refers to such layers which are sensitive to visible light (about 
400-700 nm), ultraviolet light (about 300-400 nm) or infrared light (about 
700-1500 nm). 
When reference in this application is made to a particular moiety as a 
"group", this means that the moiety may itself be unsubstituted or 
substituted with one or more substituents (up to the maximum possible 
number). For example, "alkyl group" refers to a substituted or 
unsubstituted alkyl, while "benzene group" refers to a substituted or 
unsubstituted benzene (with up to six substituents). Generally, unless 
otherwise specifically stated, substituent groups usable on molecules 
herein include any groups, whether substituted or unsubstituted, which do 
not destroy properties necessary for the photographic utility. Examples of 
substituents on any of the mentioned groups can include known 
substituents, such as: halogen, for example, chloro, fluoro, bromo, iodo; 
alkoxy, particularly those "lower alkyl" (that is, with 1 to 6 carbon 
atoms, for example, methoxy, ethoxy; substituted or unsubstituted alkyl, 
particularly lower alkyl (for example, methyl, trifluoromethyl); thioalkyl 
(for example, methylthio or ethylthio), particularly either of those with 
1 to 6 carbon atoms; substituted and unsubstituted aryl, particularly 
those having from 6 to 20 carbon atoms (for example, phenyl); and 
substituted or unsubstituted heteroaryl, particularly those having a 5 or 
6-membered ring containing 1 to 3 heteroatoms selected from N, O, or S 
(for example, pyridyl, thienyl, furyl, pyrrolyl); acid or acid salt groups 
such as any of those described below; and others known in the art. Alkyl 
substituents may specifically include "lower alkyl" (that is, having 1-6 
carbon atoms), for example, methyl, ethyl, and the like. Further, with 
regard to any alkyl group or alkylene group, it will be understood that 
these can be branched or unbranched and include ring structures. 
The emulsion layer of the photographic element of the invention can 
comprise any one or more of the light sensitive layers of the photographic 
element The photographic elements made in accordance with the present 
invention can be black and white elements, single color elements or 
multicolor elements. Multicolor elements contain dye image-forming units 
sensitive to each of the three primary regions of the spectrum. Each unit 
can be comprised of a single emulsion layer or of multiple emulsion layers 
sensitive to a given region of the spectrum. The layers of the element, 
including the layers of the image-forming units, can be arranged in 
various orders as known in the art. In an alternative format, the 
emulsions sensitive to each of the three primary regions of the spectrum 
can be disposed as a single segmented layer. 
A typical multicolor photographic element comprises a support bearing a 
cyan dye image-forming unit comprised of at least one red-sensitive silver 
halide emulsion layer having associated therewith at least one cyan 
dye-forming coupler, a magenta dye image-forming unit comprising at least 
one green-sensitive silver halide emulsion layer having associated 
therewith at least one magenta dye-forming coupler, and a yellow dye 
image-forming unit comprising at least one blue-sensitive silver halide 
emulsion layer having associated therewith at least one yellow dye-forming 
coupler. The element can contain additional layers, such as filter layers, 
interlayers, overcoat layers, subbing layers, and the like. All of these 
can be coated on a support which can be transparent or reflective (for 
example, a paper support). 
Photographic elements of the present invention may also usefully include a 
magnetic recording material as described in Research Disclosure, Item 
34390, November 1992, or a transparent magnetic recording layer such as a 
layer containing magnetic particles on the underside of a transparent 
support as in U.S. Pat. No. 4,279,945 and U.S. Pat. No. 4,302,523. The 
element typically will have a total thickness (excluding the support) of 
from 5 to 30 microns. While the order of the color sensitive layers can be 
varied, they will normally be red-sensitive, green-sensitive and 
blue-sensitive, in that order on a transparent support, (that is, blue 
sensitive furthest from the support) and the reverse order on a reflective 
support being typical. 
The present invention also contemplates the use of photographic elements of 
the present invention in what are often reflected to as single use cameras 
(or "film with lens" units). These cameras are sold with film preloaded in 
them and the entire camera is returned to a processor with the exposed 
film remaining inside the camera. Such cameras may have glass or plastic 
lenses through which the photographic element is exposed. 
In the following discussion of suitable materials for use in elements of 
this invention, reference will be made to Research Disclosure, September 
1996, Number 389, Item 38957, which will be identified hereafter by the 
term "Research Disclosure I." The Sections hereafter referred to are 
Sections of the Research Disclosure I unless otherwise indicated. All 
Research Disclosures referenced are published by Kenneth Mason 
Publications, Ltd., Dudley Annex, 12a North Street, Emsworth, Hampshire 
P010 7DQ, ENGLAND. The foregoing references and all other references cited 
in this application, are incorporated herein by reference. 
The silver halide emulsions employed in the photographic elements of the 
present invention may be negative-working, such as surface-sensitive 
emulsions or unfogged internal latent image forming emulsions, or positive 
working emulsions of the internal latent image forming type (that are 
fogged during processing). Suitable emulsions and their preparation as 
well as methods of chemical and spectral sensitization are described in 
Sections I through V. Color materials and development modifiers are 
described in Sections V through XX. Vehicles which can be used in the 
photographic elements are described in Section II, and various additives 
such as brighteners, antifoggants, stabilizers, light absorbing and 
scattering materials, hardeners, coating aids, plasticizers, lubricants 
and matting agents are described, for example, in Sections VI through 
XIII. Manufacturing methods are described in all of the sections, layer 
arrangements particularly in Section XI, exposure alternatives in Section 
XVI, and processing methods and agents in Sections XIX and XX. 
With negative working silver halide a negative image can be formed. 
Optionally a positive (or reversal) image can be formed although a 
negative image is typically first formed. (In this case, antifogging dyes 
give improved D.sub.max). 
The photographic elements of the present invention may also use colored 
couplers (e.g. to adjust levels of interlayer correction) and masking 
couplers such as those described in EP 213 490; Japanese Published 
Application 58-172,647; U.S. Pat. No. 2,983,608; German Application DE 
2,706,117C; U.K. Patent 1,530,272; Japanese Application A-113935; U.S. 
Pat. No. 4,070,191 and German Application DE 2,643,965. The masking 
couplers may be shifted or blocked. 
The photographic elements may also contain materials that accelerate or 
otherwise modify the processing steps of bleaching or fixing to improve 
the quality of the image. Bleach accelerators described in EP 193 389; EP 
301 477; U.S. Pat. No. 4,163,669; U.S. Pat. No. 4,865,956; and U.S. Pat. 
No. 4,923,784 are particularly useful. Also contemplated is the use of 
nucleating agents, development accelerators or their precursors (UK Patent 
2,097,140; U.K. Patent 2,131,188); development inhibitors and their 
precursors (U.S. Pat. No. 5,460,932; U.S. Pat. No. 5,478,711); electron 
transfer agents (U.S. Pat. No. 4,859,578; U.S. Pat. No. 4,912,025); 
antifogging and anti color-mixing agents such as derivatives of 
hydroquinones, aminophenols, amines, gallic acid; catechol; ascorbic acid; 
hydrazides; sulfonamidophenols; and non color-forming couplers. 
The elements may also contain filter dye layers comprising colloidal silver 
sol or yellow and/or magenta filter dyes and/or antihalation dyes 
(particularly in an undercoat beneath all light sensitive layers or in the 
side of the support opposite that on which all light sensitive layers are 
located) either as oil-in-water dispersions, latex dispersions or as solid 
particle dispersions. Additionally, they may be used with "smearing" 
couplers (e.g. as described in U.S. Pat. No. 4,366,237; EP 096 570; U.S. 
Pat. No. 4,420,556; and U.S. Pat. No. 4,543,323.) Also, the couplers may 
be blocked or coated in protected form as described, for example, in 
Japanese Application 61/258,249 or U.S. Pat. No. 5,019,492. 
The photographic elements may further contain other image-modifying 
compounds such as "Development Inhibitor-Releasing" compounds (DIR's). 
Useful additional DIR's for elements of the present invention, are known 
in the art and examples are described in U.S. Pat. Nos. 3,137,578; 
3,148,022; 3,148,062; 3,227,554; 3,384,657; 3,379,529; 3,615,506; 
3,617,291; 3,620,746; 3,701,783; 3,733,201; 4,049,455; 4,095,984; 
4,126,459; 4,149,886; 4,150,228; 4,211,562; 4,248,962; 4,259,437; 
4,362,878; 4,409,323; 4,477,563; 4,782,012; 4,962,018; 4,500,634; 
4,579,816; 4,607,004; 4,618,571; 4,678,739; 4,746,600; 4,746,601; 
4,791,049; 4,857,447; 4,865,959; 4,880,342; 4,886,736; 4,937,179; 
4,946,767; 4,948,716; 4,952,485; 4,956,269; 4,959,299; 4,966,835; 
4,985,336 as well as in patent publications GB 1,560,240; GB 2,007,662; GB 
2,032,914; GB 2,099,167; DE 2,842,063, DE 2,937,127; DE 3,636,824; DE 
3,644,416 as well as the following European Patent Publications: 272,573; 
335,319; 336,411; 346,899; 362,870; 365,252; 365,346; 373,382; 376,212; 
377,463; 378,236; 384,670; 396,486; 401,612; 401,613. 
DIR compounds are also disclosed in "Developer-Inhibitor-Releasing (DIR) 
Couplers for Color Photography," C. R. Barr, J. R. Thirtle and P. W. 
Vittum in Photographic Science and Engineering, Vol. 13, p. 174 (1969), 
incorporated herein by reference. 
It is also contemplated that the concepts of the present invention may be 
employed to obtain reflection color prints as described in Research 
Disclosure, November 1979, Item 18716, available from Kenneth Mason 
Publications, Ltd, Dudley Annex, 12a North Street, Emsworth, Hampshire 
P0101 7DQ, England, incorporated herein by reference. The emulsions and 
materials to form elements of the present invention, may be coated on pH 
adjusted support as described in U.S. Pat. No. 4,917,994; with epoxy 
solvents (EP 0 164 961); with additional stabilizers (as described, for 
example, in U.S. Pat. No. 4,346,165; U.S. Pat. No. 4,540,653 and U.S. Pat. 
No. 4,906,559); with ballasted chelating agents such as those in U.S. Pat. 
No. 4,994,359 to reduce sensitivity to polyvalent cations such as calcium; 
and with stain reducing compounds such as described in U.S. Pat. No. 
5,068,171 and U.S. Pat. No. 5,096,805. Other compounds which may be useful 
in the elements of the invention are disclosed in Japanese Published 
Applications 83-09,959; 83-62,586; 90-072,629; 90-072,630; 90-072,632; 
90-072,633; 90-072,634; 90-077,822; 90-078,229; 90-078,230; 90-079,336; 
90-079,338; 90-079,690; 90-079,691; 90-080,487; 90-080,489; 90-080,490; 
90-080,491; 90-080,492; 90-080,494; 90-085,928; 90-086,669; 90-086,670; 
90-087,361; 90-087,362; 90-087,363; 90-087,364; 90-088,096; 90-088,097; 
90-093,662; 90-093,663; 90-093,664; 90-093,665; 90-093,666; 90-093,668; 
90-094,055; 90-094,056; 90-101,937; 90-103,409; 90-151,577. 
The silver halide used in the photographic elements may be silver 
iodobromide, silver bromide, and silver chlorobromide and silver 
chloroiodobromide, wherein the silver chloride content is less than or 
equal to 30%. 
The type of silver halide grains preferably include polymorphic, cubic, and 
octahedral. The grain size of the silver halide may have any distribution 
known to be useful in photographic compositions, and may be either 
polydipersed or monodispersed. 
Tabular grain silver halide emulsions may also be used. Tabular grains are 
those with two parallel major faces each clearly larger than any remaining 
grain face and tabular grain emulsions are those in which the tabular 
grains account for at least 30 percent, more typically at least 50 
percent, preferably &gt;70 percent and optimally &gt;90 percent of total grain 
projected area. The tabular grains can account for substantially all (&gt;97 
percent) of total grain projected area. The tabular grain emulsions can be 
high aspect ratio tabular grain emulsions--i.e., ECD/t&gt;8, where ECD is the 
diameter of a circle having an area equal to grain projected area and t is 
tabular grain thickness; intermediate aspect ratio tabular grain 
emulsions--i.e., ECD/t=5 to 8; or low aspect ratio tabular grain 
emulsions--i.e., ECD/t=2 to 5. The emulsions typically exhibit high 
tabularity (T), where T (i.e., ECD/t.sup.2)&gt;25 and ECD and t are both 
measured in micrometers (.mu.m). The tabular grains can be of any 
thickness compatible with achieving an aim average aspect ratio and/or 
average tabularity of the tabular grain emulsion. Preferably the tabular 
grains satisfying projected area requirements are those having thicknesses 
of &lt;0.3 .mu.m, thin (&lt;0.2 .mu.m) tabular grains being specifically 
preferred and ultrathin (&lt;0.07 .mu.m) tabular grains being contemplated 
for maximum tabular grain performance enhancements. When the native blue 
absorption of iodohalide tabular grains is relied upon for blue speed, 
thicker tabular grains, typically up to 0.5 .mu.m in thickness, are 
contemplated. 
High iodide tabular grain emulsions are illustrated by House U.S. Pat. No. 
4,490,458, Maskasky U.S. Pat. No. 4,459,353 and Yagi et al EPO 0 410 410. 
Tabular grains formed of silver halide(s) that form a face centered cubic 
(rock salt type) crystal lattice structure can have either {100} or {111} 
major faces. Emulsions containing {111} major face tabular grains, 
including those with controlled grain dispersities, halide distributions, 
twin plane spacing, edge structures and grain dislocations as well as 
adsorbed {111} grain face stabilizers, are illustrated in those references 
cited in Research Disclosure I, Section I.B.(3) (page 503). 
The silver halide grains to be used in the invention may be prepared 
according to methods known in the art, such as those described in Research 
Disclosure I and James, The Theory of the Photographic Process. These 
include methods such as ammoniacal emulsion making, neutral or acidic 
emulsion making, and others known in the art. These methods generally 
involve mixing a water soluble silver salt with a water soluble halide 
salt in the presence of a protective colloid, and controlling the 
temperature, pAg, pH values, etc., at suitable values during formation of 
the silver halide by precipitation. 
In the course of grain precipitation one or more dopants (grain occlusions 
other than silver and halide) can be introduced to modify grain 
properties. For example, any of the various conventional dopants disclosed 
in Research Disclosure, Item 38957, Section I. Emulsion grains and their 
preparation, sub-section G. Grain modifying conditions and adjustments, 
paragraphs (3), (4) and (5), can be present in the emulsions of the 
invention. In addition it is specifically contemplated to dope the grains 
with transition metal hexacoordination complexes containing one or more 
organic ligands, as taught by Olm et al U.S. Pat. No. 5,360,712, the 
disclosure of which is here incorporated by reference. 
It is specifically contemplated to incorporate in the face centered cubic 
crystal lattice of the grains a dopant capable of increasing imaging speed 
by forming a shallow electron trap (hereinafter also referred to as a SET) 
as discussed in Research Disclosure Item 36736 published November 1994, 
here incorporated by reference. 
The SET dopants are effective at any location within the grains. Generally 
better results are obtained when the SET dopant is incorporated in the 
exterior 50 percent of the grain, based on silver. An optimum grain region 
for SET incorporation is that formed by silver ranging from 50 to 85 
percent of total silver forming the grains. The SET can be introduced all 
at once or run into the reaction vessel over a period of time while grain 
precipitation is continuing. Generally SET forming dopants are 
contemplated to be incorporated in concentrations of at least 
1.times.10.sup.-7 mole per silver mole up to their solubility limit, 
typically up to about 5.times.10.sup.-4 mole per silver mole. 
SET dopants are known to be effective to reduce reciprocity failure. In 
particular the use of iridium hexacoordination complexes or Ir.sup.+4 
complexes as SET dopants is advantageous. 
Iridium dopants that are ineffective to provide shallow electron traps 
(non-SET dopants) can also be incorporated into the grains of the silver 
halide grain emulsions to reduce reciprocity failure. To be effective for 
reciprocity improvement the Ir can be present at any location within the 
grain structure. A preferred location within the grain structure for Ir 
dopants to produce reciprocity improvement is in the region of the grains 
formed after the first 60 percent and before the final 1 percent (most 
preferably before the final 3 percent) of total silver forming the grains 
has been precipitated. The dopant can be introduced all at once or run 
into the reaction vessel over a period of time while grain precipitation 
is continuing. Generally reciprocity improving non-SET Ir dopants are 
contemplated to be incorporated at their lowest effective concentrations. 
The contrast of the photographic element can be further increased by doping 
the grains with a hexacoordination complex containing a nitrosyl or 
thionitrosyl ligand (NZ dopants) as disclosed in McDugle et al U.S. Pat. 
No. 4,933,272, the disclosure of which is here incorporated by reference. 
The contrast increasing dopants can be incorporated in the grain structure 
at any convenient location. However, if the NZ dopant is present at the 
surface of the grain, it can reduce the sensitivity of the grains. It is 
therefore preferred that the NZ dopants be located in the grain so that 
they are separated from the grain surface by at least 1 percent (most 
preferably at least 3 percent) of the total silver precipitated in forming 
the silver halide grains. Preferred contrast enhancing concentrations of 
the NZ dopants range from 1.times.10.sup.-11 to 4.times.10.sup.-8 mole per 
silver mole, with specifically preferred concentrations being in the range 
from 10.sup.-10 to 10.sup.-8 mole per silver mole. 
Although generally preferred concentration ranges for the various SET, 
non-SET Ir and NZ dopants have been set out above, it is recognized that 
specific optimum concentration ranges within these general ranges can be 
identified for specific applications by routine testing. It is 
specifically contemplated to employ the SET, non-SET Ir and NZ dopants 
singly or in combination. For example, grains containing a combination of 
an SET dopant and a non-SET Ir dopant are specifically contemplated. 
Similarly SET and NZ dopants can be employed in combination. Also NZ and 
Ir dopants that are not SET dopants can be employed in combination. 
Finally, the combination of a non-SET Ir dopant with a SET dopant and an 
NZ dopant. For this latter three-way combination of dopants it is 
generally most convenient in terms of precipitation to incorporate the NZ 
dopant first, followed by the SET dopant, with the non-SET Ir dopant 
incorporated last. 
The photographic elements of the present invention, as is typical, provide 
the silver halide in the form of an emulsion. Photographic emulsions 
generally include a vehicle for coating the emulsion as a layer of a 
photographic element. Useful vehicles include both naturally occurring 
substances such as proteins, protein derivatives, cellulose derivatives 
(e.g., cellulose esters), gelatin (e.g., alkali-treated gelatin such as 
cattle bone or hide gelatin, or acid treated gelatin such as pigskin 
gelatin), deionized gelatin, gelatin derivatives (e.g., acetylated 
gelatin, phthalated gelatin, and the like), and others as described in 
Research Disclosure I. Also useful as vehicles or vehicle extenders are 
hydrophilic water-permeable colloids. These include synthetic polymeric 
peptizers, carriers, and/or binders such as poly(vinyl alcohol), 
poly(vinyl lactams), acrylamide polymers, polyvinyl acetals, polymers of 
alkyl and sulfoalkyl acrylates and methacrylates, hydrolyzed polyvinyl 
acetates, polyamides, polyvinyl pyridine, methacrylamide copolymers, and 
the like, as described in Research Disclosure I. The vehicle can be 
present in the emulsion in any amount useful in photographic emulsions. 
The emulsion can also include any of the addenda known to be useful in 
photographic emulsions. 
The silver halide to be used in the invention may be advantageously 
subjected to chemical sensitization. Compounds and techniques useful for 
chemical sensitization of silver halide are known in the art and described 
in Research Disclosure I and the references cited therein. Compounds 
useful as chemical sensitizers, include, for example, active gelatin, 
sulfur, selenium, tellurium, gold, platinum, palladium, iridium, osmium, 
rhenium, phosphorous, or combinations thereof. Chemical sensitization is 
generally carried out at pAg levels of from 5 to 10, pH levels of from 4 
to 8, and temperatures of from 30 to 80.degree. C., as described in 
Research Disclosure I, Section IV (pages 510-511) and the references cited 
therein. 
The silver halide may be sensitized by sensitizing dyes by any method known 
in the art, such as described in Research Disclosure I. The dye may be 
added to an emulsion of the silver halide grains and a hydrophilic colloid 
at any time prior to (e.g., during or after chemical sensitization) or 
simultaneous with the coating of the emulsion on a photographic element. 
The dyes may, for example, be added as a solution in water or an alcohol. 
The dye/silver halide emulsion may be mixed with a dispersion of color 
image-forming coupler immediately before coating or in advance of coating 
(for example, 2 hours). 
Photographic elements of the present invention are preferably imagewise 
exposed using any of the known techniques, including those described in 
Research Disclosure I, section XVI. This typically involves exposure to 
light in the visible region of the spectrum, and typically such exposure 
is of a live image through a lens, although exposure can also be exposure 
to a stored image (such as a computer stored image) by means of light 
emitting devices (such as light emitting diodes, CRT and the like). 
Photographic elements comprising the composition of the invention can be 
processed in any of a number of well-known photographic processes 
utilizing any of a number of well-known processing compositions, 
described, for example, in Research Disclosure I, or in T. H. James, 
editor, The Theory of the Photographic Process, 4th Edition, Macmillan, 
New York, 1977. In the case of processing a negative working element, the 
element is treated with a color developer (that is one which will form the 
colored image dyes with the color couplers), and then with a oxidizer and 
a solvent to remove silver and silver halide. In the case of processing a 
reversal color element, the element is first treated with a black and 
white developer (that is, a developer which does not form colored dyes 
with the coupler compounds) followed by a treatment to fog silver halide 
(usually chemical fogging or light fogging), followed by treatment with a 
color developer. Preferred color developing agents are 
p-phenylenediamines. Especially preferred are: 
4-amino N,N-diethylaniline hydrochloride, 
4-amino-3-methyl-N,N-diethylaniline hydrochloride, 
4-amino-3-methyl-N-ethyl-N-(b-(methanesulfonamido) ethylaniline 
sesquisulfate hydrate, 
4-amino-3-methyl-N-ethyl-N-(b-hydroxyethyl)aniline sulfate, 
4-amino-3-b-(methanesulfonamido)ethyl-N,N-diethylaniline hydrochloride and 
4-amino-N-ethyl-N-(2-methoxyethyl)-m-toluidine di-p-toluene sulfonic acid. 
Dye images can be formed or amplified by processes which employ in 
combination with a dye-image-generating reducing agent an inert transition 
metal-ion complex oxidizing agent, as illustrated by Bissonette U.S. Pat. 
Nos. 3,748,138, 3,826,652, 3,862,842 and 3,989,526 and Travis U.S. Pat. 
No. 3,765,891, and/or a peroxide oxidizing agent as illustrated by Matejec 
U.S. Pat. No. 3,674,490, Research Disclosure, Vol. 116, December, 1973, 
Item 11660, and Bissonette Research Disclosure, Vol. 148, August, 1976, 
Items 14836, 14846 and 14847. The photographic elements can be 
particularly adapted to form dye images by such processes as illustrated 
by Dunn et al U.S. Pat. No. 3,822,129, Bissonette U.S. Pat. Nos. 3,834,907 
and 3,902,905, Bissonette et al U.S. Pat. No. 3,847,619, Mowrey U.S. Pat. 
No. 3,904,413, Hirai et al U.S. Pat. No. 4,880,725, Iwano U.S. Pat. No. 
4,954,425, Marsden et al U.S. Pat. No. 4,983,504, Evans et al U.S. Pat. 
No. 5,246,822, Twist U.S. Pat. No. 5,324,624, Fyson EPO 0 487 616, 
Tannahill et al WO 90/13059, Marsden et al WO 90/13061, Grimsey et al WO 
91/16666, Fyson WO 91/17479, Marsden et al WO 92/01972. Tannahill WO 
92/05471, Henson WO 92/07299, Twist WO 93/01524 and WO 93/11460 and 
Wingender et al German OLS 4,211,460. 
Development is followed by bleach-fixing, to remove silver or silver 
halide, washing and drying. 
The following examples illustrate the use of dyes of formula I to sensitize 
and reduce fog in photographic elements. 
PREATION OF EMULSION: 
The following solutions were prepared: 
Solution A. Sodium thiocyanate, 680 g/L 
Solution B. Silver nitrate, 1.526 mole/L 
Solution C. Sodium bromide, 1.442 mole/L 
Potassium iodide, 0.054 mole/L 
A vessel was charged with 42.4 L of a 1.24 wt % gel solution and warmed to 
73 degrees C. 0.57 L of solution A was added, then 12.6 L of solution B 
and 14.6 L of solution C were added simultaneously at a constant rate over 
35 min. An additional 1.8 L of solution B was then added over 5 min. The 
emulsion was then cooled to 30 degrees C. Salts were removed by three 
cycles of lowering the pH to precipitate the gel and decanting the 
solution, followed by reconstitution to pH 5.2 and the initial volume with 
water. After the third wash the VAg of the emulsion was adjusted to 75 by 
the addition of 3.86 M sodium bromide solution. 5.96 L of 9.75 wt % 
gelatin was added and 4-chloro-3,5-xylenol as a preservative. This 
produced a polydisperse, polymorphic emulsion that was 94% bromide and 6% 
iodide, and had an average grain size of 0.37 micron. 
Chemical Sensitization. The above emulsion was chemically sensitized with 
1.3 mg/Ag mole potassium tetrachloroaurate and 2.6 mg/Ag mole sodium 
thiosulfate pentahydrate. The thiosulfate was added at a temperature of 
40.degree. C. followed by the gold. The emulsion was then heated at a rate 
of 1.67 degrees/min to 65.degree. C. and held at that temperature for 25 
min before chilling at 10.degree. C.

EXAMPLE 1 
Sample 1-1 was prepared as follows. 0.013 mole of the above emulsion was 
dyed with 0.4 mmole/Ag mole of dye A by adding a methanol solution of the 
dye to the emulsion at 40 degrees C. After waiting twenty minutes, a 
dispersion of cyan coupler CC-1 (7 wt % coupler, 4 wt % dibutyl phthalate, 
7.25% gelatin, 1wt % Alkanol XC, and propionic acid), and 2 g/Ag mole 
tetraazaindene were added with additional gelatin, and saponin as a 
coating aid. 
The emulsion and coupler were then coated on gelatin subbed acetate support 
at a coated coverage of 150 mg silver/ft.sup.2., 90 mg coupler/ft.sup.2, 
and 450 mg gelatin/ft.sup.2. Samples 1-2 through 1-21 were prepared 
similarly using the dyes listed in Table I. Sample 1-22 was treated with 
methanol solvent like sample 1-1, but no dye was added. This coating of 
undyed emulsion served as a reference for the dyed emulsions. 
Coatings were given a 1/50 second wedge spectral exposure and processed 
using KODAK FLEXICOLOR C41 process as described in Brit. J. Photog. 
Annual, 1988, p196-198 with the exception that the composition of the 
bleach solution was changed to comprise propylenediaminetetraacetic acid. 
The propensity of the dyes to restrain fog was assessed four ways. 
1) The minimum density of the fresh coatings was recorded after exposure 
and processing as above. 
2) Three sets of coatings were given increasing times of development (TOD), 
2', 3'15", and 4'30" and the difference in minimum density between 2' and 
4'30" was recorded. 
3) One set of coatings was given accelerated aging by incubating it for 2 
weeks at 100 degrees Fahrenheit and 50% relative humidity. This set was 
exposed and processed as above and compared to a set that was kept at room 
temperature for 2 weeks. The difference between the minimum density of the 
incubated and room temperature coatings was recorded. 
4) One set of coatings was stored for 4 months at ambient temperature and 
humidity, then exposed and processed as above. The difference between the 
minimum density of the aged coatings and the fresh coatings was recorded. 
These data are recorded in Table I. 
The comparative dyes used in this example are: 
Comparison Dyes: 
TABLE I 
__________________________________________________________________________ 
##STR10## 
1 Dye A 
2 #STR11## Dye B 
3 #STR12## Dye C 
4 #STR13## Dye D 
5 #STR14## Dye E 
6 #STR15## Dye F 
7 #STR16## Dye G 
8 #STR17## Dye H 
9 #STR18## Dye J 
0 #STR19## Dye K 
1 #STR20## Dye L 
2 #STR21## Dye M 
.DELTA. Dmin 
.DELTA. Dmin 4 
.DELTA. Dmin 
incubated - 
months - 
Sample 
Dye Fresh Dmin 
TOD room kept 
fresh Note 
__________________________________________________________________________ 
1-1 A 0.21 0.225 
-0.005 0.00 Comp 
1-2 B 0.20 0.25 0.045 0.05 Comp 
1-3 C 0.25 0.33 0.485 0.13 Comp 
1-4 D 0.33 0.47 0.115 0.10 Comp 
1-5 E 0.16 0.245 
0.01 0.06 Comp 
1-6 I-1 0.08 0.09 0.085 0.03 Inv 
1-7 I-2 0.08 0.055 
0.01 0.05 Inv 
1-8 II-1 
0.11 0.13 0.015 0.05 Inv 
1-9 F 0.23 0.295 
0.10 0.13 Comp 
1-10 G 0.18 0.275 
0.075 0.09 Comp 
1-11 H 0.19 0.175 
0.015 0.05 Comp 
1-12 I-3 0.16 0.11 0.02 -0.03 Inv 
1-13 J 0.46 0.595 
-0.055 -0.07 Comp 
1-14 I-4 0.09 0.04 0.025 0.02 Inv 
1-15 K 0.74 0.665 
-0.01 0.03 Comp 
1-16 L 0.19 0.25 0.085 0.13 Comp 
1-17 II-2 
0.11 0.10 0.02 0.05 Inv 
1-18 I-5 0.11 0.05 0.005 0.02 Inv 
1-19 II-3 
0.14 0.13 0.025 0.08 Inv 
1-20 M 0.16 0.19 0.06 0.09 Comp 
1-22 none 
0.20 0.22 0.09 0.105 
Ref 
__________________________________________________________________________ 
The dyes of the invention are seen to restrain fog in several of the tests 
used while being no worse for fog in any of the other tests. All dyes of 
the invention have less fog than the undyed reference (sample 1-22), while 
some comparison dyes enhance fog growth. 
The invention has been described in detail with particular reference to 
certain preferred embodiments thereof, but it will be understood that 
variations and modifications can be effected within the spirit and scope 
of the invention.