Here’s a fun fact. Longer lenses compress things and make them look really close together.
I put this to good use in alligator-filled swamp on the Texas coast at the great Fennessey Ranch.
Here is the story.
I had been photographing from a floating blind out in the swamp and noticed lots of birds roosting in this spot as the sun set behind them. But they were down deep in the reeds, and I could not get a decent shot. So me and the ranch manger (my friend Mog) and some other friends floated a dead tree to that spot one day and set it upright (it’s amazing what an 8 foot T-post and some bailing wire can do!).
That evening, I came back and, sure enough, the grackles hopped right up into that tree and fought for the best perch. I used a 500mm lens and stacked two 2x teleconverters to give me 2000mm focal length, and that in turn gave me one great big sun behind bickering grackles. I brought a pair of welding goggles along to look through and focus. I did that back in film days – I am not sure I would do that today with a sensitive and expensive digital camera sensor!