Most of the top actors and actresses may be working in ten or twelve films at the same time, so they will give one director two hours and maybe shoot in Bombay in the morning and Madras in the evening. It happens. ↗
Well the Bombay film wasn't always like how it is now. It did have a local industry. There were realistic films made on local scenes. But it gradually changed over the years. ↗
When I'm shooting on location, you get ideas on the spot - new angles. You make not major changes but important modifications, that you can't do on a set. I do that because you have to be economical. ↗