The stock SH3 and GWX "free roam" cameras do allow you to "fly" to the same altitude as passing aircraft to take screen shots.
Sometimes I've buzzed an airplane halfway back to its base just to admire the detail that was put into the model, right down to the crew visible through the cockpit glass.
I thought Sergbuto's free camera mod did not alter this.
You can also try asanovic7's Little Camera Mod. It works in a similar fashion to Sergbuto's but is based on the GWX 2.1 camera files and may allow you to take screenshots of the aircraft.