Normally, if a layer is turned on (checked on) in the table of contents, ArcMap will draw it. However, as you zoom out, it may become difficult to see more detailed information, or as you zoom in, information may become too coarse. While you can turn off a layer, this can be inconvenient and time consuming, especially if your map contains several layers or if you change the scale frequently as you work.
Layers can be set to automatically display only within an appropriate range of map scales. This is sometimes referred to as scale-dependent drawing. Here are the steps to set this up for a map layer.
Setting the visible scale range
Right-click the layer in the table of contents and click Properties (or double-click the layer) to open the Layer Properties dialog box. You can set a layer's visible scale range on the General tab of the Layer Properties dialog box.
Specifying visible map scales can be tricky. Scales are fractions; 1:25,000 means 1/25,000th. Larger numbers typically refer to smaller map scales.
Out beyond refers to the smallest desired map scale at which the layer is visible in the display (the minimum scale). This will use the larger of the map scale numbers. In beyond refers to the largest desired visible map scale, which is the smaller of the map scale numbers (the maximum scale).
Once you set the range of visible map scales, whenever the scale of the data frame is outside the layer's visible scale range, the layer will not draw. You'll see a dimmed check box in the table of contents.
Setting a visible scale based on the current map display
You can use your map display to set the visible scale range of a map layer as follows:
- Navigate the map until you have the desired display at the most zoomed-out map scale.
- Right-click the layer and click Visible Scale Range.
- Click Set Minimum Scale to set the smallest visible map scale.
- Repeat the process to set the largest visible map scale by zooming in and clicking Set Maximum Scale.
Setting the visible scale range for group layers
Group layers are also a useful shortcut when you need to set visible scale ranges for more than one layer. The map can be designed for use at a number of map scales (for example, view this U.S. topographic map in your Web browser).
You'll see that this map is designed to draw at over a dozen map scales (within the United States).
Just like this basemap example, it often makes sense to create group layers for each scale range within a multiscale map. To do this, you can add map layers to each group layer for a map scale and set the visible scale range for each group layer.
The scale range for each group layer overrides the scale range of any sublayers within the group layer. To further refine the level of detail shown within your map, you can set any of the layers within a group layer to turn on or off at scales that fall within the scale range of the group layer.
Working with layers whose visible scale range has been set
Here are some typical tasks for working with scale-dependent display in ArcMap.
Zooming the map to make a layer visible
Right-click a layer that is currently not being drawn because of the map's scale and click Zoom To Make Visible.
ArcMap zooms to the nearest scale at which the layer will become visible. This command makes it easy to view a scale-dependent layer.
Clearing a layer's visible scale
Right-click the layer for which you want to clear a visible scale range and click Visible Scale Range > Clear Scale Range.