You can change settings and mess around all you want but the problem will always be the size of your pixels. I assume you have a 1920x1200 res ofcourse.
The game uses a certain amount of pixels for certain tasks(like bogeys at 5+km for example) and when those pixels are smaller than on a 1600x1080, they will naturally be harder to spot. The only real solution is to get a larger size screen, given that the resolution stays the same. Or a similar size monitor with lower resolution.
