March 31 2015
One common fault in landscape photograph is either the sky is overexposed, or the scene itself is too dark. When we view a landscape our eyes compensate for the changes in brightness in different parts of the scene, resulting in our evenly exposed mental picture.
Unfortunately cameras use the same exposure settings for the whole photo. However, photographers have developed a number of techniques to overcome this problem. These photography techniques are used while taking the photo or later during processing printing. Most of the photography techniques used in the digital era derive from film practices.
Exposure For Highlights
If the bright areas of the landscape are overexposed then the details are lost as they are recorded as pure white. Check the camera’s histogram for excessive numbers of pixels to the right. The image in the example histogram is overexposed.
If there is a great deal of light colours, or pure white, objects then there will be a lot of pixels on the right of the histogram. There is no definite rule, it is a matter of experience and personal preference. It is possible to recover some of this seemingly lost detail by using the techniques outlined below.
Use raw format in the camera
All the following digital processing adjustments work better when they are applied to raw image data. During the processing of a jpeg image file much of the detail is thrown away. The image data may not be essential for the final version, but with more choices there is more precision in the exposure adjustments.
Some purists argue that altering the image in post shooting processing destroys the authenticity of the photograph. But all photographs are processed at some stage. In-camera processing is choosing a set of cookie cutter exposure adjustments decided by someone without even seeing the scene.
A traditional technique is using a graduated neutral density filter in front of the camera lens to reduce light entering part of the lens. The amount of light reduction varies from maximum at the top, to none part of the way down the filter. Photographers move the filter so it reduces the light from the sky but the not the rest of the scene. The graduation helps blend the transition from bright sky to the darker landscape.
There is a digital photography era version of the graduated filter in Adobe Lightroom, and it offers a greater range of adjustments than exposure. I find using the saturation adjustment in conjunction with the exposure slider helps to bring out the colour in blue skies without too much darkening.
The graduated neutral density filter works well when there is an even transition between the land, or water, and the sky. Where there are tall features the stick up into the sky the graduated filter can’t tell difference. The filter reduces the exposure of the upright feature, as well as the sky.
These situations are dealt with by selectively varying the exposure during processing. The film darkroom technique is to vary the amount of light to sections of the image while printing a photograph to alter the exposure in selected areas. The digital era selection tools are usually far more flexible.
Selective Area Adjustments
The choice of tools is between those that select a complex shaped area where the same level of adjustments are applied to the selected area. In Adobe Lightroom the digital adjustment brush tool paints on the area for adjustment. The selected area is indicated by a coloured overlay that is turned off while changing the exposure of the selected area. This works well on simple shapes with well defined edges.
Selective Tone Adjustments
Then there are adjustment s based on light levels, such as the basic curves tool that underlies many seemingly simple slider adjusters. This is very good where there is even balance of light and dark areas across all the elements in the scene. For more complex light level adjustment try HDR.
High Dynamic Range (HDR) processing is a new digital tool where adjustments are based on light levels independent of any physical area. This allows exposure adjustments to areas that are too complex for normal selection tools. HDR processing sometimes produces amazing results, and sometimes they are awful. It can be applied to single images, as well as the normal HDR procedure of multiple shots with different exposures.
What do I use?
Well, all of them except for the old physical filter. Often I use combinations of small adjustments using the range of the tools available in Adobe Lightroom.