Level of expertise required for this Chapter: Beginner; general Map Maker training
‘Zoom-in’ to see more detail, like to be ‘closer’, but with a smaller area covered.
‘Zoom-out’ to see less detail like from higher above ground, with a larger area.
The easiest way to zoom in and out is to use the + and – buttons on the keyboard.
Alternatively, you can use the vertical scroll bar at the bottom right.
Or, use the Zoom-tool from the toolbar left and define the window to zoom in.
Or, you zoom to a defined scale through Main menu > Navigate > Zoom to scale.
If you want to see the entire area, select Main menu > Navigate > Zoom to extent.
Observe the screen scale at the bottom left.
When digitizing new data, zoom in to half of the intended scale number. For example, when working on a 1:25,000 map (Structure Plan), zoom in to start digitizing at 1:12,500 (see also Annex 2.6 for scale discussion).
With paper maps the scale is a given fact. With digital mapping this aspect seems lost: One can zoom at any scale and the sense that maps are created with a specific intended scale in mind, is completely lost.
- - - - -
You can make layers invisible depending on the scale through the drop in / out option. When reducing the scale from very detailed to more general, you specify when it becomes visible (example below: 1:10,000), and when it becomes invisible again (example below, 1:200,000). For example, a detailed map of topography or communities should appear at all very detailed levels (enter 0 as the drop in scale), but not at more general scales, as it would make the entire map unreadable (enter 100000 as the drop out scale).
- - - - -
LUPMIS exercise: Zoom to all of Ghana. Which scale is this? Zoom to scale of 1:1 Mio, 1:100,000, 1:10,000 etc.