I have a project and a topomap in WGS84 (EPSG4326).
On the fly CRS transformation is activated.
I open Google satellite layer from the OpenLayers plugin.
The Google layer is WGS84 / Pseudo Mercator (EPSG3857).
But then the whole project has also become WGS84 / Pseudo Mercator (EPSG3857).
I thought on the fly transformation would reproject to EPSG4326. Why is that? Is it better to work directly in WGS84 / Pseudo Mercator (EPSG3857) systematically when we use Google Earth?
Best Answer
The Openlayers plugin fetches tiles from Google or Openstreetmap servers which come in EPSG:3857. If you would reproject them to another CRS tile by tile, the result would look rather ugly. That's why the developer decided to insist on the project CRS bound to EPSG:3857, so that every other data gets reprojected, but not the tiles. And that is the same the original Openlayers works.
A solution would be to download all relevant tiles, stitch them together, reproject and display the result. But that would take too much time.