Wired get their geeky little mits on a DVD copy of The Last Jedi and start to look at the science elements of the film. For example, how can a Resistance member standing on D’Qar see a Star Destroyer many klicks overhead? Allow Rhett Allain to explain (because I certainly can’t).
Based on the scene from The Last Jedi, how far away are the Star Destroyers when they show up? There is always a problem with movies in that the angular field of view for the camera isn’t always something that is known. In this case, there is something to help out. It’s a great shot with a Resistance person in the foreground and the Star Destroyer in the distance. If I estimate the location of the camera and the person, I can get a value for the field of view and then measure the angular size of the Star Destroyer.
Let’s say the Resistance person has a head diameter of 18 cm and is a distance of 2.5 meters from the camera. Using this to set the field of view, I get 30.9°. This puts the angular size of the Star Destroyer at 0.75° at a distance of 221 kilometers. That’s actually pretty low altitude since the view is closer to the horizon and not directly overhead. Still, it seems pretty plausible overall. I’m pretty happy this works out since the scene is pretty cool.