Complex sentence: Principal photography took place from 1956 to 1958 over a period of 156 days, which was more than the usual amount of time taken for shooting as most films were completed in 40-50 days.
Split into simpler sentences: Principal photography took place from 1956 to 1958 over a period of 156 days, which was more than the usual amount of time taken for shooting. Most films were completed in 40-50 days.