I see a number of posts about changing the resolution of an output of a map; however, my problem is that the map itself is lacking in adequate resolution. When working in the main QGIS program, I can zoom in and see much detail in my underlying aerial photo. However, when I make a map using Print Composer, I cannot zoom in without losing too much resolution. It becomes pixillated.
I have tried increasing the size of the map, but that doesn't seem to make any difference. My properties are set to "render", not "cache". Under "Variables\Composition\layout_dpi" it is 300; but I can't seem to change that, or don't know how.