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Figure 11-31.A processed test strip.
Making Enlargement Prints

Journalist 3 & 2 - Introduction to Journalism and other reporting practices
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CAUTION Never attempt to work backwards through the sink-line process. A few drops of fixer on your hands or from a print will contaminate the developer. PROJECTION  PRINTING LEARNING    OBJECTIVE:    Recognize    the purpose   of   projection   printing,   identify   the main   difference   between   projection   and contact   printing,   and   summarize   the advantages of projection printing. Projection printing is the process of making positive prints   by   projecting   the   negative   image   onto photosensitive   paper.   The   projected   image   may   be enlarged,   the   same   size   as   the   negative   image,   or reduced in size. When the print images are larger than the  negative  images,  the  process  is  called  enlarging. When  the  print  images  are  smaller  than  the  negative images,   the   process   is   called   reducing.   Because projection  printing  is  usually  used  to  make  positive prints with images larger than the negative, projection printers  are  usually  referred  to  as  enlargers.  The  term enlarging  generally  refers  to  all  forms  of  projection printing. DIFFERENCES  BETWEEN  PROJECTION AND CONTACT PRINTING Projection  printing  differs  from  contact  printing because the negative is separated from the paper and the image is projected by a lens onto the sensitized material. The negative is placed between an enclosed light source and  a  lens.  The  lens  receives  the  light  that  passed through  the  negative  and  projects  the  image  onto  the paper. Changing the distance between the lens and the paper  controls  the  size  of  the  image.  The  image  is focused on the paper by adjusting the distance between the  negative  and  the  lens.  It  is  possible  to  enlarge  or reduce the size of the projected image by changing and adjusting these distances. Enlarging is a very adaptable and versatile process because  considerable  image  and  exposure  control  can be used The main advantage of enlarging over contact printing is that large prints can be made, but there are several other important advantages. The advantages of projection printing areas follows: l  Cropping  (selecting  the  main  area  of  interest in a negative) can be done and enlarged to any l l l l suitable size. This gives you the opportunity to eliminate   unwanted   and   distracting   elements from around the point of interest of the picture. Dodging or burning in. This allows you to apply local exposure control to bring out more detail in the highlight and shadow areas. Local fogging with a small external light, such as  a  penlight,  to  darken  selected  areas.  For example, to darken the background of a portrait to direct viewer attention to the face. Special effects. You can change the appearance of  the  image  by  use  of  diffusers  or  patterns between the lens and paper. Image  distortion  correction  or  introduction can be done by tilting the enlarger easel.  An easel is the device used to hold the paper during exposure. ENLARGERS In general, all enlargers are similar in design and operation.  They  have  an  enclosed  light  source,  some method of providing an even distribution of light over the negative, a negative carrier, a lens, and a means of adjusting   the   lens-to-negative   and   lens-to-paper distances.  There  are  two  types  of  enlargers  —condenser and  diffusion. Condenser Enlarger The condenser enlarger (fig. 11-32) is the one most commonly used in Navy imaging facilities. It has a set of condensing lenses between the printing light and the negative. These lenses align and project the light rays evenly  through  the  negative.  Since  all  features  of  the negative  are  being  enlarged,  any  flaws  also  will  be enlarged. Diffusion Enlarger The diffusion enlarger (fig. 11-33) has a diffusing medium  (usually  a  ground  glass)  between  the  light source and the negative to spread the light evenly over the entire surface of the negative. Light emitted from the lamp,   as   well   as   that   reflected   from   the   parabolic reflector, strikes the diffuser, which, in turn, scatters it in  all  directions.  Thus,  when  the  light  reaches  the negative, it is traveling in a nondirectional pattern. Most  enlargers  have  a  tungsten  lamp  as  a  light source. The lamp is enclosed in a lighttight housing that 11-36







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