On mobile devices, you can zoom in and out at will. Zooming in is appreciated by the map makers as it allows more precise drawing and sketching and more accurate display of the background map.

However, by zooming in and out, map makers are not working at a fixed scale and so the sense of distance within the map is lost. This was easier when mapping with pen and paper where the scale was fixed.

A few things can be done to improve the feeling for the scale on a mobile device:

Working with the OCAD Sketch App

• Make use of the scale bar that has been added in the latest update of the app. The scale bar can be turned on or off in the settings.

• Adjust the distance between the north lines. You can do so in the settings.
  E.g., set it to 1mm in a project with a 1:10’000. This gives you every 10 meters a line. In a 1:4’000 project, use 2.5mm to get a line every 10 meters.

• Know the different line widths. It is advantageous to know the line widths and to sketch objects accordingly. E.g., an impassable wall on a sprint map with a line width of 0.4mm and contour lines with a line width of 0.21mm.

Working on a Windows Tablet

• Similar to the north lines in the App, you can adjust the Grid Distance in the Set Scale and Coordinate System dialog or Create a Map Grid.

• In OCAD Desktop, it is also possible to check directly during drawing whether the drawn line or area object corresponds to the minimum dimension of the IOF, as we explain in this blog post.