difference is great, the negative is said to be contrasty. When the density difference is small, the negative is said to be flat or lacking in contrast. For a negative to have normal contrast, the density differences between the highlight and shadow areas of the negative must be proportional to the reflective brightness range of the subject photographed A  contrasty  negative  usually  is  the  result  of overdevelopment  but  also  may  be  caused  by  a  high scene lighting ratio (a contrasty original scene). A flat negative, on the other hand, may be caused, primarily, by underdevelopment or a low-contrast original scene. TONAL  GRADATION Photographers  often  concentrate  on  the  density  and detail of highlights and shadows when they should actually be considering the most important or middle tones of the negative. Middle tones are the various tones of gray between the highlights and the shadows; that is, the densities that are not highlights or shadows are termed middle tones or intermediate tones. The middle tones vary with the type of film and the subject contrast. A negative should have a range of middle tone densities that correspond proportionally to the middle reflective brightness  of  the  subject.  A  panchromatic  negative  that does not have proportionate midtones is contrasty or flat. GRAININESS Because photographic images made from film are made up of fine silver grains, the images may appear “grainy”  or  exhibit  graininess  (fig.  10-22). All negatives show graininess to some extent. The most  important  factors  affecting  negative  graininess  are as follows: The composition of the emulsion or the inherent graininess of the emulsion. That is to say, the size of the grains  used  to  produce  the  emulsion. The type of developer used. When fine grain is desired, a fine-grain developer with the appropriate film should be used. The  extent  of  development.  Overdevelopment  is a  major  cause  of  excessive  graininess. Exposure or negative density. Overexposure is another key contributor to graininess. As negative density  increases,  so  does  graininess. Figure 10-22.–Grain structures in emulsions. Image sharpness. The sharper the film image, the greater the image detail and the less apparent the graininess. EFFECTS  OF  EXPOSURE  AND DEVELOPMENT   VARIATIONS The nine negatives reproduced in figure 10-23 compare the effects of exposure and development variations. From the left, they show the effects of development; from the top, they show the effects of exposure.  The  center  negative  has  been  given  both correct exposure and normal development and is a “normal” negative that will print without a filter or with a No. 2 filter. Negatives 1, 4, and 7 have been underdeveloped, while 3, 6 and 9 have been overdeveloped. The  negatives  across  the  top-1,  2,  and  3-are underexposed and lack detail in the shadow areas. Increasing  development  (No.  3)  had  no  appreciable effect on the lack of shadow detail. Little can be done to improve negative quality when exposure is insufficient. Underexposure  is  identified  by  lack  of  shadow  detail. The negatives across the center-4, 5, and 6-were given correct exposure and all have sufficient shadow detail. However, No. 4 was underdeveloped and is flat or lacks adequate contrast. Negative No. 5 received normal development, has good shadow detail, and good contrast. It is a “normal” negative. Negative No. 6, although  having  received  correct  exposure,  was overdeveloped.  This  resulted  in  excessive  highlight density with a loss of highlight detail and excessive contrast. The highlights in both 6 and 9 are too dense. Negatives 3, 6, and 9 are all overdeveloped. The correctly exposed negative, No. 6, is so dense that almost  no  detail  is  visible  in  the  highlights.  The highlights of the overexposed and overdeveloped negative, No. 9, are completely blocked up. When  a  correctly  exposed  film  is  given  normal development  as  in  negative  No.  5,  the  negative  has 10-32