How can I choose the zoom level for my map?

According to both Notch's Twitter (no link) and the wiki, maps have some kind of settable zoom:

A zoom level, which will somehow be decided at the time the map is created.

I have no idea how to set this. Anyone know?

EDIT: based on fjdumont's answer, how is it calculated? Is there anything I can do (such as craft it in a certain place) to give it a zoom level close to what I want?


Solution 1:

You can zoom map files, but you have to do it by editing your NBT files. This answer is thanks to this redditor:

If you're willing to dive deep into the NBT files, you can adjust the map's center and zoom levels. Just don't screw with dimension (locks the map) or width/height — it doesn't work. The files are under <map-name>/Data/map_X.dat, where X is the map number.

You'll need to use an editor like NBTEdit to edit the files.

Solution 2:

From version 1.4, you can zoom maps in game, as the whole process of map-making is changed:

  1. First, a blank map is created
    enter image description here
    This blank map will not start recording immediately, as maps previously did.

  2. The blank map can be activated by right clicking it, which turns it into a map at the most zoomed in level (1 px/1 block)

  3. To scale the map by a factor of two, take the map and recraft it as follows: enter image description here
    Each time this is done the map will scale out, so from 1px -> 1 block, to 1 px -> 4 blocks, to 1 px -> 16 blocks and so on. This can be done a maximum of 5 times. Maps cannot be scaled back in, only out.

Solution 3:

Looks like yes, this is the work of a mod. Here's how you can do it:

  1. Download NBTedit from here
  2. Unzip the ZIP file
  3. Run NBTedit
  4. Click File -> Open
  5. Navigate to your save folder
  6. Go to the "Data" folder
  7. Open the map_0 file. If its not map_0 you want to edit, choose the right one.
  8. Expand the "data: 7 entries" branch
  9. Change the "scale" value to the one you want. I chose 1, but it can be anything.

Solution 4:

I have made a program specifically for map item files. You can find it here http://sourceforge.net/projects/mapitemedit/

You can edit your zoom level, map coordinates, even change the picture data.

Solution 5:

When crafting a zoomed out map with eight pieces of paper, shift-clicking on the output map in the crafting table does not make a newly scaled map

in the bug section of the wiki

http://www.minecraftwiki.net/wiki/Map_(item)