5,460,919  21  22  No. 2 (using  the  emulsion  containing  the  sensitizing  dye).  acid), a pH  buffer (e.g.,  sodium tertiary  phosphate,  sodium  carbonate,  potassium  carbonate,  sodium metaborate,  and  lithium  tetraborate),  an  inorganic  antifoggant  (e.g., sodium  bromide  and  potassium  bromide),  an  organic antifoggant  (e.g.,  1-phenyl-5-mercaptotetrazole  and  5-nitroindazole),  an  organic solvent  (e.g., ethylene  glycol, diethylene  glycol, and  methyl cellosolve),  a color  toning agent,  a  surface active  agent,  a  defoarning  agent,  a hard water  softener,  etc., in  addition  to the  foregoing  components  in the range  of not  reducing  the effects  of the  invention.  The  processing  temperature  of the  developer  of the  present invention  is in the range  of from 18°  C. to 50°  C. and  preferably  from 20°  C. to 40°  C.  After exposing  each of the  film samples  thus prepared  to  a  tungsten lamp  of  2666°  K.  using an LB-200  filter through  a step  wedge having  a step  difference  of 0.15 for  5  second,  each sample  was  developed  with each  of  developers  1, 2, 3,  and 4 having  the  following  compositions,  stopped,  fixed,  washed, and  dried.  t,1060  The  photographic  characteristics  obtained  are shown  in  Table 1.  t,1080  In the above  table, the  relative sensitivity  was the relative  value of  the  reciprocal  of the  exposure  amount  of giving  density 3.0  of the sample  being evaluated  from which  fog  was  subtracted  with the  sensitivity  of film sample  No. 1 in  Test No.  1  developed  with  Developer  1 for 5  minutes  at 20°  C. being  defined  as 100. The  gamma was  shown by  the mean  slope between  the  densities  0.5 and 3.0  from which  fog was  subtracted  and the fog  was shown  by the  density  at the  unexposed  area.  As is clear  from the  results shown  in Table  1, when the  film sample  containing  a large  amount  of the dye  having  a  negative  reduction  potential  satisfying  the factor  of the  present invention  is  developed  with the  developer  containing  the  arninophenol  derivative  developing  agent and  the reduc- tone  compound,  remarkably  high  sensitivity  and high  con› trast are obtained.  However,  when film  samples  are devel› oped with  Developer  2  (Kodak D-11  Formula;  High› Contrast  MQ  Developer)  described  in Akira Sasai,  Saishin  Shashin  Shoho  Binran  (Newest  Photographic  Formula  Handbook),  published  by  Shashin Kogyo  Shuppan  Sha,  1983,  Developer  3  (FD-185  Formula,  by Fuji Photo  Film  Co., Ltd,;  Lith Type  Developer),  or  Developer  4 (a  developer  formula  for super  high-contrast  development  using the  hydrazine  derivative),  a high  contrast  is not  obtained  and a  remarkably  high  sensitivity  is not  obtained  even when  a  large amount  of the dye  having  a  negative reduction  poten- tial is  incorporated  in the film  samples.  As a fixing  solution  for use in  this  invention,  a  compo› sition generally  used can  be used. For  example,  the fixing  agents described  in  Shashin  Kogaku  no Kiso,  Gin-en  Shashin  Hen (The  Foundation  of  Photographic  Engineering,  Silver Halide  Photography),  page 330  and below,  edited by  Nippon Shashin  Gakkai, published  by  Corona Publishing  Co., Ltd.,  1979; Akira  Sasai,  Shashin  no  Kagaku  (Chemistry  of  Photography),  page 320  and below,  published  by  Shashin  Kogyo Shuppan  Sha, 1982;  and  W.  Thomas,  Jr.,  SPSE  Handbook  of  Photographic  Science  and  Engineering,  page  528,  published  by John Wiley  &  Sons, 1973  can be referred  to.  As the  fixing agent,  thiosulfates,  thiocyanates,  and  organic sulfur  compounds  which are  known  to have the  effect as  a fixing agent  can be used.  Also, as  an  auxiliary  fixing agent,  an acid agent  (e.g., acetic  acid and  citric acid),  a  preservative  (e.g., sodium  sulfite),  a  buffer (e.g.,  boric  acid), and  a  hardening  agent (e.g.,  potassium  alum, alumi› num alum,  and  aluminum  sulfate) can  be used for  the fixing  solution.  Then, the  invention  is  explained  more  practically  by  following  examples  but the  invention  is not  limited  to the  examples  within the  scope of  the present  invention.  The  foregoing  phenomenon  of  obtaining  a high  sensitivity  and a  high-contrast  by the dye  having  a  negative  reduction  potential  has not been  known until  now and  an utterly  new  fact  discovered  by the  inventors.  By  simultaneously  adding an  aqueous silver  nitrate solu- tion and  an  aqueous  solution  of a  mixture  of  potassium  bromide  and sodium  chloride  (Br:Cl=30:70  by molar  ratio)  containing  sodium  hexachlororhodate(III)  in an  amount  of  l.5x10- $^{7 }$mol per mol  of silver to  an  aqueous gelatin  solution  kept at 40°  C. while  keeping pAg  at 7.2 over  a  period of75  minutes,  a  monodispersed  silver  chlorobromide  emulsion  (AgC170  mol  %)  containing  the cubic  crystal silver  halide  grains having  a mean grain  size of 0.28  µm  was  prepared.  Then, after  removing  soluble salts  by an  ordinary  method,  5x10- 5  mol of sodium  thiosulfate  per mol of  silver halide  was added  to the  emulsion  and the  emulsion  was  subjected  to  chemical  ripening  at 50°  C. for 100  minutes.  The silver  halide emulsion  obtained contained  80 g of gelatin  per mol  of silver  halide.  By  simultaneously  adding an  aqueous silver  nitrate solu› tion and  an  aqueous solution  of a  mixture  of  potassium  bromide  and sodium  chloride  (Br:Cl=30:70  by molar  ratio)  containing  sodium  hexachlororhodate(Ill)  in an  amount  of  l.5x10- $^{7 }$mol per mol  of silver to  an  aqueous gelatin  solution  kept at 40°  C. while  keeping pAg  at 7.2 over  a  period of  75  minutes,  a  monodispersed  silver  chlorobromide  emulsion  (AgCl 70  mol  %)  containing  the cubic  crystal silver  halide  grains having  a mean grain  size of 0.28  µm  was  prepared.  After removing  soluble salts  therefrom  by an  ordinary  method, 5x10-s  mol of sodium  thiosulfate  per mol of  silver  halide was  added to  the silver  halide emulsion  and the  emulsion  was  subjected  to  chemical  ripening  for 120 min› utes at 52.2°  C. The silver  halide emulsion  obtained  con› tained 80  g of  gelatin per  mol of silver  halide. Then,  after  adding  to the  emulsion  6x10- $^{3 }$mol of  6-hydroxy-4-methyl- 1,3,3a,7-tetraazaindene  per mol of  silver halide,  the emul› sion was  split into  many small  portions.  Then, after  adding  to each of  the split  portions  each of  the dyes  or the  pyridinium  salt  derivatives  shown in  Table 2 below  and each  of the  polyalkylene  oxide  derivatives  and each of  the dyes or  the  pyridinium  salt  derivatives  shown in  Table 3,  each  emulsion  was coated  on a  polyethylene  terephthalate  (PET)  After adding  thereto 6x10- $^{3 }$mol of  6-hydroxy-4-methyl- l,3,3a,7-tetraazaindene  per mol of  silver halide,  the silver  halide emulsion  was split  into two  portions.  To one of  the  split  emulsions  was added  no  sensitizing  dye and to  another  split  emulsion  was added  a  sensitizing  dye (D-18,  reduction  potential -1.24  volt) at  8,000xl0---6  mol per mol  of silver  halide, and  each of the  split  emulsions  was coated  each of  polyethylene  terephthalate  bases each  having  a  subbing  layer at a  silver coverage  of 40 mg/dm 2 •  Then,  a  gelatin  protective  layer  containing  formaldehyde  and dimethy› lolurea  as  hardening  agents was  coated on  each emulsion  layer followed  by drying  to  provide film  sample No.  1 (using  the  emulsion  containing  no  sensitizing  dye) and  film sample  EXAMPLE2  EXAMPLE  1 