The Red Bull Air Races are returning to San Diego on April 15 and I plan to shoot the races from across the bay with the San Diego Skyline in the background. I was seriously considering renting a 600mm Canon f/4L IS II lens (that's where the eighty dollars comes into the equation). I don't think that I need the 600mm.
However, I looked at some images that I shot from across the Bay in an earlier shoot. This is at 80mm on a 1.6x camera.
Since I have the 100-400mm f/4.5-5.6L IS II lens, I am sure that will be long enough. I have a 1.4x TC (just in case). I have decided to take the 100-400 on my 7D2 (tripod mounted on a gimbal) and my 70-200mm f/4L IS lens on my 5D2 camera (hand held) to get more overall shots...