Hard to see the aircraft

[III/JG53_Don]

I will try your suggestion with the AF switched to 16x, thanks!
Moste of my time on the ATAG I fly around for almost an hour without spotting anything.... and then suddenly a crowd of 3-4 planes nearby "appears" (my eye just didn't caught them earlier).

Guess a little bit luck plays a role there too, but (apart from the weak high level performance of nearly all planes) it has a reason that the vast amount of fights takes place below 2000m imho.....
When you're up high its almost impossible to spot a plane below.