1. Open Adrenaline settings by holding home and tapping settings in the top right corner.
2. Hit L or R until you're on the "Main" menu.
3. Hit X on "Open Official Settings", go down to "Other settings", then open "Screen mode" and set it on "original". Then uncheck Bilinear Filtering.
4. Open Adrenaline settings again, hit L or R until you're on the "Settings" menu.
5. Select any filter, Bilinear, Sharp Bilinear, Advance AA, LCD3x, (do NOT select original).
6. "Smooth graphics" can be on or off, it doesn't matter.
7. Go down to "Screen Scale X PS1" set it to 1.500. For "Screen Scale Y PS1" select 1.160. (You may have to tweak this depending on what game you're playing, but I found these setting to be good "universal" variables.)
Screenshots work. PNGshot plugin recommended.