riscpc wrote:
Your main problem going to 2,000 to 3,000 will be Haze especially on a hot humid day.
This could degrade the final shot.
Are you assuming that because it has a longer focal length they are going to take more distant pictures? It could be the longer focal length is just to get things bigger in the frame.
I often use a 400mm shooting birds from my porch. Today I used an 800mm shooting from the same distance. The difference was that today's target was Hummingbirds. No additional haze.