You have to play with the settings - I mean, start with the lowest possible and work your way up, one type of setting at once, so you can judge the difference. I prefere having the Pixel Density set to 1.0, and multisampling turned on, as this gives better spotting. With higher PD you won't be able to spot any aircraft, as the dots are not visible any more. Especially a problem in normandy with radarless WWII aircraft.
Regards,
Huzzle