How to Improve Contrast? フォト・レタッチ講座：コントラストを上げるには

  There are many situtations when it is hard to get a photography with good contrast, or dynamic range. One example is a cloudy day, or a shiny day around noon time. In both cases, things all look either too dull or too bright both in color and brightness. As a result, the photographs all look very "flat", with details less obvious, and more two dimentional than three.
  There are two quick solution is to improve the contras, or dynamic range of a photograph. One is to adjust the brightness, and the other is to adjust the tone curve.
Below is an exmaple when using Adobe's lightroom.
  The original photograph below is taken in a fine and cloudless day, has a histogram mostly assembled around the center. The eroded surface of the stone is not obvious as it actually is.

  By reducing the brightness as below, the contrast becomes higher and the surface erosion becomes more obvious, or more three dimensional. It is worth noting that reducing exposure and brightness in Lightroom has different effects. The later not only reduce the overall brightness, but can also increase the contrast.

  Further more, by adjusting the tone curve from its orginal straight line to "S" shape, higher contrast has been obtained, and the errosion becomes more vivid.