Sometime during the Sixties, audience eyes started rejecting back projection and backlot fob-offs as unrealistic, in both film and television. This coincided with the transition from black-and-white to color, not coincidentally.
With Hawaii Five-O, which premiered in 1968, we have definitely arrived at full-scale television series location filming. It was not the very first location show, but it made a major impact and helped to change the ground rules.
One thing Hawaii Five-O did NOT do, interestingly, was to follow those other shows in emphasizing the attractions of the unfettered masculine lifestyle. Everyone on the team was very work-focused, and we seldom got a sense of their private enjoyments; it would be quite the surprise if Steve McGarrett had any. Despite the Hawaii setting, the show was not in the least hedonistic in tone, and concentrated on the seamy side of island life.