The aspect ratio of the map frame doesn't match the contents, leaving a lot of white space inside the frame, even after I've scaled the contents to fill one dimension. When I drag one edge of the frame to change the aspect ratio, the scale of the content changes. I know I can zoom with the mouse wheel, but the jumps are too big. Is there a way to set the sensitivity of the zoom? Alternatively is there a better way to change the map's aspect ratio so that the scale doesn't change?
qgis 2.01 64 bit
windows 7


I don't think it is possible to lock a map's scale in the composer - as much as I'd like to see this feature. But you can easily set your desired map scale, just select the map, go to Item Properties and type your desired map scale in the field called scale (1:3250 in my example below, I also rotated my map by 25° for layout purposes):

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  • I know that I can type in a scale in Item Properties, but that's mainly helpful when you have a known scale you're trying to achieve. When your goal is to zoom to fill the space, that really doesn't work, esp when the scale is a number like 5169231, as is the case in my map. – Llaves Nov 29 '13 at 22:12

In my experience it's easiest to work with the Set to map canvas extent button. All you have to do is to zoom to the desired extent in the QGIS main window (not print composer). Then change to composer, add the map item, and press Set to map canvas extent. When you change the map item, just press the button again.

  • 2
    This approach fails if the map canvas isn't sized to roughly match the bounding box of the map item. Imagine you're mapping an area which is roughly square in a map canvas that has an aspect ratio of about 2:1. If I create a square map item in composer, then click Set to Map Canvas extent, the zoom is set such that the width of the canvas fits in the map item, which is as it should be, but doesn't achieve the result of the square area filling the map item. You still need to find the right zoom to make it work. I suppose I can resize the canvas to match the map item, but that seems hacky. – Llaves Dec 1 '13 at 5:07

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