Expression Value: Map Frame Threshold _photothreshold#

Expression Element: Built-in Properties

Map Frame Threshold

This property dictates what items are drawn, without affecting the scale of the output in any way.

The initial Map Frame threshold will be the same as the Map Frame item's scale. Choosing a different scale threshold will mean that the data displayed in the Map Frame (and printed) will be the same as that which is displayed when zooming to this particular scale. For example, with OS (GB) Land-Line 1:1250, 1:2500, 1:10000 data, if you zoomed to 1:2500 on screen, Building Seeds would disappear. Similarly, by choosing a Map Frame threshold of 2500, Building seeds will not appear on the print.

Many items in mapping datasets have their own scale ranges within which to become visible. The Map Frame threshold scale is compared against the scale range for each item inside the Map Frame to determine which items to draw.

Expression Syntax:_photothreshold#