I started a print composer project and added my map onto the composer canvas and it was displayed with really poor resolution. My map consists of a georeferenced jpeg ( big 90Mb) and a slope layer overlay on top. Why is it displayed with very poor resolution? Is that what the print will look like?
The map contents do not scale when you zoom in or out. You have to refresh the map layout by pressing f5 when you have the map selected. This will "update" the map to view the correst resolution for your current zoom. When you print the map it will of course display a sharp image.