HBO’s 1930s-set “Perry Mason” required production designer John P. Goldsmith to step even further back in time than the original incarnation of the show, as seen in the 1950s. Furthermore, since the titular character (played by Matthew Rhys) was working as a private investigator (not yet a lawyer) in the new drama, Goldsmith and visual-effects supervisor Justin Ball had to steep the series in a noir style to reflect the kind of gritty justice that might be served.

The process started with Goldsmith researching real-life 1930s Los Angeles. He relied on the internet — in particular waterandpower.org, where he pulled from archives of roads, dams, signs, buildings and everything he needed to begin the process to recreate the old world on new soundstages. He also found crime scene archives from the Los Angeles Police Department a helpful resource.

When researching the design of his exteriors, it was all about looking up. “You can find so much great material from the second floor up,” Goldsmith says, referring to the tops of buildings and powerlines.

But, when it came to the sidewalks, Goldsmith had to change post boxes, streetlamps and even traffic lights to be period accurate. “This is where my world overlapped with Justin,” he says. “Central Los Angeles has become so modernized that there’s less fabric to work with.”

So, he and the production ventured further afield: The dairy farm location was in Thousand Oaks, and Central Avenue was recreated in the San Pedro area of Los Angeles. Other locations he found were as far afield as Pomona and Pasadena — a 40-mile radius in total. “It was a drive, but a lot of the bones were still there,” he says.

It was then up to Ball and the VFX team to digitally replace items in footage shot at those locations to reflect what the areas looked like almost a century ago. This included finding versions of hallmark buildings and structures, as well as adding a lot more greenery than the Los Angeles landscape houses today.

“There would be a hill, and now it’s no longer there because it had to make place for a stadium,” Ball says. “The city changed so dramatically. In the ’20s and ’30s, it was really downtown and then farmland out to the coast.”

Additionally, the Angels Flight railway that connected Hill Street and Olive Street no longer exists in its original location. It was moved in the late 1960s to Hill Street and Grand Avenue on Bunker Hill.

The team could only work with the bottom of the real flight, so Goldsmith built additional pieces of it for scenes shot at that location. Ball then had to composite in the original tunnel.

Another critical part of Ball’s work was creating the oil derricks. Goldsmith’s team designed and built a single oil derrick to be used at the location of Strickland’s home.

“We then took those plans and built additional versions of them in 3D and 2D,” Ball says. “All the other oil derricks seen in the show were VFX. We wanted to create the feeling of the oil fields that littered Southern California at the time.”