[Qgis-user] Help with scales in print layouts for geographic CRS

[Patrick Dunford]

On 6/04/22 11:34, Greg Troxel via Qgis-user wrote:
> Jorge Gustavo Rocha via Qgis-user <qgis-user at lists.osgeo.org> writes:
>
> 2) Using a geographic CRS, the same 150mm x 150mm map, at the same
>> 1:10000 scale, the area is bigger then the 1500m polygon. The result
>> is attached https://nextcloud.geomaster.pt/index.php/s/H2eAytsPANyxn6Y
>>
>> On both layouts the scale bar widget is working properly. The
>> distances (and areas) are properly calculated in QGIS interface. I
>> have set the GRS 1980 ellipsoid for distance and area calculations.
> What does it mean to use a geographic CRS for a print layout?  Do you
> really expect longitude on the x axis and latitude on the y axis?  The
> value of meters/degree is different for x and y, unless you are at or
> near the equator.  (Living at 42N-ish, I'm very aware of this.)
>
>
This may be the case for projections like EPSG:3857 that are based on a 
spherical projection of the Earth but is it the case for all projections?