I am trying to save a QGIS layer (the layer in question is an STRM geotiff, downloaded from Earthexplorer with resolution 1801 x 3601) in the project CRS projection (WGS 84 EPSG:3857), as an image file. However, no matter which options I choose it ALWAYS saves in the native resolution of 1801 x 3601. The layer appears perfect in the QGIS project window, but the saved-as image is always 1801 x 3601. (the WGS 84:3857 should be approx 1801 x 3200 I think, based off a basic measurement of the width x height in the project window). In the save as options, there is even a drop down list to select the CRS, but it has no effect on the final image produced.
(The screen grab below is not using 3857 CRS but still demonstrates the problem I am having)
I can change the resolution manually, I know, but for my project I need the rendered image to be exactly as per the WGS84 EPSG:3587 resolution.