[Qgis-user] scale WMS layer

[Goyo]

2011/4/11 Federico Lazzaroni <fedelazza at gmail.com>:

> I'm trying to set a less detailed scale for a WMS raster layer (I need to
> use a origina 1:10.000 topographic map at 1:15.000). Is there a way to
> "force" this setting?

A WMS request include a bounding box (in CRS units) and image size (in
pixels). I guess QGIS determines the bounding box from the map extents
and the image size from the screen (or printing) resolution.

I tried with WMS "Property" -"General" "Visibility
> depending froms scale" but nothing changes....
> Furthermore, when I prepare a Printing with the same WMS, I usually can't
> keep the same scale I was using in the project. If I use 1:10.000 in the
> project I can' use more than 1:4500 in "Printings".

What does "I can't" mean?
Many servers impose a limit in the size of images they serve. Usually
a printed map needs a bigger image than a screen one so you can see
the image in the screen but maybe not in the printing.

I often download several images and use virtual rasters to compose a
bigger one in order to workaround these limits.

Goyo