One of my favorite YouTube channels, Every Frame a Painting, has a video on this https://m.youtube.com/watch?v=ojm74VGsZBU

...and Seattle

And Toronto is New York City.

I thought it was funny that almost every alien planet on Stargate SG-1 looked like British Columbia.

Nah, you can tell because they don’t have annoying people paint street numbers on the curbs.

That said it’d be difficult to film the film Bullitt in Vancouver unless they cut out a lot of the street scenes, the marina, San Bruno mountain, the old freeways…

Tax breaks for filming and it's not SF specific or even cities. Other planets, like Stargate being filmed around Squamish 1 hour away.

Psych (the TV show) was set in Santa Barbara but filmed in Vancouver. They then did an episode where the plot was that characters all took a trip to British Columbia, which I recall being amusingly meta.

Or in the case of Superbad, a film based on Seth Rogen's experiences as a Vancouver teenager in the late 90s, Vancouver is a stand-in for Los Angeles, which is a stand-in for Vancouver.

You can also tell if something was shot in Canada by all the Canadian actors all over the place. I recognize so many people from X-Files, and so many other shows.

Also Battlestar Galactica -multiple shots of homes in Vancouver- I remember watching the series and wondering what city was being used for Baltar's house and surroundings because it was so beautiful, futuristic and clean..then I went vistied Vancouver.. its truly a gorgeous city and area

http://www.battlestarlocations.com/locations-guide/the-minis...

My mother worked in a factory that sewed drapes for film sets before she retired. My brother-in-law used to be an operations manager for a warehouse that rented equipment to film sets.

There is just a very long tail of services and a robust supply chain that is required for most industries to be successful.