Local Adjustments

The cartographer has to selectively adjust light direction and brightness of important landforms when producing shaded relief. For shading derived from a DEM, necessary local adjustments are achievable by two different methods:

Photoshop allows for the selective correction of grey values or to combine multiple shaded relief images created with differing illumination direction. This is a rather tedious, but currently the only viable method.

An alternative is the use of software specifically designed to apply local adaptations to a shaded relief as shown below.

No adjustmentLocal adjustment
Local adjustment of the light direction. Left: A mountain ridge illuminated from the northwest. Right: A fence containing locally adjusted illumination from the southwest.

The images below compare a manual shading with an analytical shading that employs locally adjusted light direction and brightness parameters.

Manual shading (Mt. Rigi)
Manual shading.
Local adjustments (Mt. Rigi, small)
Analytical shading with local adjustments.