Changing the illumination angle of a hillshade
You may want to change the illumination angle when applying a shaded relief or hillshade to a digital elevation model (DEM). There are three locations within the ArcMap window where the illumination properties can be altered:
- On the Data Frame Properties dialog box
- On the Image Analysis window's Processing Options dialog box
- From the Layer Properties dialog box
To change the illumination properties for a data frame, do the following:
- Right-click the data frame containing the DEM layer and click Data Frame Properties.
- Click the Illumination tab.
- Adjust the azimuth angle.
- Adjust the altitude angle.
- Optionally, you can adjust the contrast of the hillshading.
- Click Apply to see the changes.
- Click OK to close the Data Frame Properties dialog box.
To change the illumination properties that are applied when creating a hillshaded or shaded relief layer using the Image Analysis window, do the following:
- Click the Image Analysis Options button on the Image Analysis window.
- Click the Hillshade tab and adjust the illumination properties.
- Click OK to close the Processing Options dialog box.
The illumination properties must be set before you click the Shaded Relief button; otherwise, you need to follow the steps below.
To change the illumination properties for a hillshaded or shaded relief layer created from the Image Analysis window, do the following:
- Create your hillshaded raster layer using the Shaded Relief button.
- Right-click the raster layer in the table of contents and click Properties.
Click the Functions tab.
Functions are added within a mosaic dataset and by the temporary raster layers created from the Image Analysis window. They are used to define processing, which is applied on the fly.
- Right-click Shaded Relief Function and click Properties.
- Click the Shaded Relief tab and edit the properties.
- Click OK to close the Raster Properties Function dialog box and click OK again to close the Layer Properties dialog box.