Many landscape photographers show little or no human activity in their photos, striving to attain pure, unsullied landscapes that are devoid of human influence, using instead subjects such as strongly defined landforms, weather, and ambient light. Despite this, there is no pure or absolute definition of what makes a landscape in photography, as such it has become very broad term, encompassing urban, industrial, macro and nature photography. A beach full of parasols and sunbathers can be a landscape photo, but so can the view through an electron microscope, which shows a different type of landscape. Waterfalls, coastlines, seascapes and mountains are especially popular in classic landscape photography. Though many photographs are inspired by traditional landscape painting, the term in photography broader; most places and things can be photographed as a landscape, a kitchen, a lamp, a wall, or even the human body can be turned into a rolling vista by a skilled photographer. A crucial element of landscape photography is the light to the scenery. Preferred times are dusk or dawn with low angle light which renders the landscape with low contrast and sidelight. This light adds a feeling of depth to the picture and the low contrast usually is beneficial for the picture as there are no harsh contrasts and the very details can be captured. Notable landscape photographers include Ansel Adams, Galen Rowell and Edward Weston.
[edit]Environmentalism and landscape photography
From its beginnings and continuing into the present era, some of the most important and celebrated landscape photographers have been motivated not only by artistic aims but also by a love of the natural environment, as well as a desire to see it preserved. For example, Ansel Adams, acknowledged as a pioneer in landscape photography and one of its greatest practitioners, wrote that "It is horrifying that we have to fight our own government to save the environment. More recently, Galen Rowell, in an interview with BBC journalist Simon Willis, said, "The reason that I keep writing is that all my most powerful messages about the fates of wild places that I care about need to have words as well as images."
Technical Aspects

Camera
The genre often calls for high resolution DSLR, Medium or Large Format cameras to record the very details of the scenery. For digital cameras, the preferred file format is RAW, as RAW allows to record a wider dynamic range and all information is retained. With RAW, the camera does not process the file in a destructive way, all information is kept, resulting in significant high file sizes.

Lenses
Usually wide angle lens (24 mm and 35 mm are especially popular) are used to capture the vast scenery of a landscape. For artistic expression, telephoto lenses are used to compress the scenery and emphasize certain aspects (e.g. rendering the moon very big beyond a mountain ridge). For high quality, the lenses are very often prime lenses rather than zoom lenses. Some landscape photographers however prefer medium telephoto lenses and prefer to capture a typical part of a particular scene revealing the detail of the landscape rather than use wide angle lenses that show the vastness of the scene but which lack detail and can be non-specific.

Filters
To reduce contrast or control exposure, a split neutral density or polarizing filter are used very often. Neutral density filters are used to extend exposure and allow to include motion blur (e.g. for waterfalls or waves) in the scenery. Control of contrast was the major motivator to create the Zone System, often associated with Ansel Adams. Today, the Zone System may become obsolete for digital landscape photographers as HDR allows a very good control of contrast by combining several exposures of the scenery to one single picture.

Other Equipment
A tripod and a cable release is very often used for landscape photography as this allows minimal camera shake and thus very sharp pictures.

Post Production
Digital Photography has provided landscape photographers with a very useful post production tool. Conventional photographs give pictures revealing the best average of brightness and colour. HDR post production work allows the photographer to darken and brighten particular parts of the overall scene ( skies often appear brighter in photographs than originally seen) or to tweak colours either to give a more accurate rendition of the scene as seen originally by the photographer or to dramatically enhanse it as in boosting yellows for instance to make an autumnal picture look more so. Burning and dodging have always been used in black and white photography to make landscapes more artistic but difficult to do in colour before the advent of digital photography.

http://en.wikipedia.org/wiki/Landscape_photography