On Tue, 14 Jul 2020 at 09:41, Greg Troxel <[email protected]> wrote: > > Nyall Dawson <[email protected]> writes: > > > On Tue, 14 Jul 2020 at 05:59, Randal Hale > > <[email protected]> wrote: > >> > >> I hope everyone is staying safe out there. > >> > >> So I've had some questions regarding setting up a QGIS Project and now > >> I've convinced myself that I'm doing this wrong. When I get a new > >> project in and I start setting up QGIS generally my project will be in a > >> Stateplane projection - in this case EPSG:2274 (TN Stateplane NAD83). > >> When I set up the project I change the ellipsoid to be > >> "none/planimetric" (In the project properties). I don't set up the > >> ellipsoid to be GRS 1980 and haven't for some time. > > > > Can I ask why you do this? > > I too am boggled by this. EPSG:2274 is a Lambert Conformal Conic > projection of NAD83, and I don't understand what it means to do that > projection to/from geodetic coordinates without an ellipsoid definition. > Using the GRS80 ellipsoid is part of the definition of this CRS, so if > you change that you are using a different CRS that is not actually 2274, > and that 2274prime CRS should throw an exception if you try to convert > to/from NAD83 geodetic.
It's actually unrelated to projection. You CAN'T change the ellipsoid used by a projection, at least without creating your own custom projection. The ellipsoid settings in project properties are only utilised for area/length calculations, not transformations. Nyall _______________________________________________ Qgis-user mailing list [email protected] List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
