The Theoretical distance depends on atmospheric conditions, and antennas you are using which could be several miles. 2.4Ghz and 5.8Ghz are very line of sight , and even a tree leaf could interfere with the signal on 5.8.
Actual distance depends on your eye sight. At 3000 feet, all you are going to be able to see is a small dot. You will not be able to tell orientation. You are also pushing the limits of being able to safely return to your area for a safe landing.
I personally have been out to 4000 feet at 150 feet altitude. My video kept dropping, and took my eyes off the aircraft to look at the controller and lost sight of it. Good thing for the RTH feature. Learned my lesson on that flight.
Now I stay usually no more than 1500 feet out. I can still see which way I am flying. Not really sure why people expect to be able to fly out miles and miles. These are professional hobby aircraft, not NASA budgeted drones. I would rather walk/drive to get closer to what I want to photograph than risk loosing my H on a long distance flight.