To  help  reduce  the  harshness  of  shadows,  plain some diffusion material, such as a white handkerchief, cheesecloth, or frosted cellulose acetate, in front of the flash. Keep in mind that diffusion reduces the intensity of the light. Therefore, the exposure must be increased accordingly  if  you  use  the  manual  mode  on  the  flash unit. Off-Camera Flash You will make some of your best flash pictures with the flash unit off the camera. When you hold the flash off the camera and above the lens, it will tend to throw the shadows down and behind the subject. This is a good way to minimize distracting background shadows that occur when a subject is standing close to a wall. A flash held high above the lens, either left or right, makes the viewer less conscious of the flash illumination. We  are  accustomed  to  seeing  things  lighted  from above,  and  by  placing  the  flash  above  the  subject,  it closely resembles the lighting of the sun or ceiling lights. Light that is far enough off the camera to illuminate the  subject  from  an  angle  produces  modeling  or roundness.  This  type  of  light  creates  the  illusion  of  a third dimension — depth — and is more pleasing to the viewer than the two-dimensional flat effect you get with direct frontlighting. Angled lighting also is used to bring out the texture of a subject. Bounce Flash One of the best methods to illuminate a subject or scene with a single flash unit is to use  bounce  flash. There will be times when you will want a very soft light in order to lessen the tonal range between highlights and shadows and to soften harsh background shadows. You can achieve this soft lighting by bouncing, or reflecting the flash off a light-colored surface. By doing so you are changing the narrow spot of light from a flash unit into a wide, diffused area of light. Most bounce flash pictures are made with the light directed at the ceiling, either above the photographer or above the subject, or somewhere in between. You can produce a silhouette effect by bouncing the flash off the ceiling behind the subject. To accomplish this, aim your flash unit so most of the light bounced off the ceiling falls on the background behind the subject and calculate the exposure for the background. For the flattest bounce light, try bouncing the light off a wall behind the camera. With this lighting you will have  practically  no  shadows.  Here  you  will  have  to calculate   your   exposure   based   on   the   flash-to- wall-to-subject distance. “RED-EYE” An  effect  that  may  appear  with  direct  flash  is “red-eye.”  Red-eye  occurs  in  pictures  of  people  and animals when the. flash is used close to the optical axis of the lens and the subject is looking at the camera. It is caused by light reflecting from the blood vessels at the back of the eye. The darker the room is, the stronger the effect  will  be  because  the  pupils  of  the  eyes  will  be dilated. Red-eye can be avoided easily by your moving the flash away from the lens optical axis. Also, you can minimize the effects of red-eye by turning up the room lights. PHOTOGRAPHIC  FILTERS LEARNING OBJECTIVE: Identify the purpose of   photographic   filters,   the   various   filter designations,   and   the   filters   used   in black-and-white and color photography. Filters  are  used  in  all  the  various  steps  of  the photographic  process.  Though  often  neglected  in  the shooting  stage,  the  use  of  filters  can  tremendously enhance the final product in both black-and-white and color  photography. PURPOSE The purpose of photographic filters is to alter the characteristics  of  light  that  reaches  the  light-sensitive emulsion. As light is transmitted through a filter, at least one of the following alterations occurs: l The color of light is modified. l The amount of light is reduced. . The vibration direction of the light rays is limited. To  use  photographic  filters  properly,  you  must understand the nature of transmitted light. White  light  is  composed  of  three  primary  colors: red,  green  and  blue.  A  filter  of  a  primary  color  will transmit  its  own  color  and  absorb  the  other  two;  for example, a red filter looks red because it transmits red and absorbs green and blue, as shown in figure 11-17. Secondary  colors  are  mixtures  of  primary  colors. Yellow, for example, is a combination of red and green. Because a filter passes its own color and absorbs others, 11-16