[Qgis-user] OTF reprojection and +towgs84 parameters

[Standaert Arnout]

>-----Original Message-----
>From: Jean-Claude Repetto [mailto:jcrml at mxm.eu] 
>
>Standaert Arnout a écrit :
>>  * set OTF projection on and project CRS to Google Mercator (EPSG 900913)
>
> Hello,
> EPSG 900913 is not defined in QGIS, you should try EPSG 3785 

Actually, 900913 was added recently in the nightly builds. I'm using the nightly OSGEO4W builds on Windows.

> If it doesn't work, try to add the parameter "+nadgrids=@null " to the 
> projection string.

What does this exactly do? 
In any case, it behaves strangely in QGis: I specified a custom CRS using my Lambert proj string (with the correct +wgs84 parameters) and adding "+nadgrids=@null", but when selecting this custom CRS in "Layer properties" (via "Specify CRS"), the proj string is not updated in the Layer properties window.

Reading around, it seems both a +towgs84 and +nadgrids parameter clause in the proj string are conflicting? Is this why QGis doesn't update the proj string with the custom one?

Getting confused more and more,
Arnout

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