There are really two looks to the original run of The X-Files, and you can date most episodes within a few seconds of the first exterior shot. One is wet, green and gray, with forests that swallow light and skies that never quite clear. The other is dry and warm, with hard sun, open roads and nights lit by the orange of sodium streetlamps. The dividing line is the summer of 1998, when production left Vancouver for Los Angeles.
Vancouver as production design
For its first five seasons the show was filmed in and around Vancouver, British Columbia. The city stood in for small towns in Oregon and Washington, suburbs of Virginia, and remote locations all over North America. Its forests, its industrial waterfront and its constant overcast did enormous work for the production.
That overcast is easy to underestimate. Flat, soft daylight with no hard shadows looks melancholy on film and is forgiving to shoot in. It also matches from shot to shot, because the light doesn't change much over an afternoon. The rain added texture to every exterior. Wet asphalt reflects whatever light you put near it, so a night street becomes a field of reflections rather than a black hole.
The result was a look that felt like a region rather than a set. The Pacific Northwest became the X-Files' landscape the way Monument Valley became John Ford's, even when the script claimed the episode was set somewhere else entirely.
The move
After season five the production moved to Los Angeles. The Beginning, the sixth-season premiere, was the first episode shot there. David Duchovny had pushed for the change, and the logic of filming closer to the studio made sense for a show now big enough to support a feature film.
Bill Roe became director of photography with the move and stayed through the end of the original run in season nine. He faced a different problem from his predecessors. Southern California light is bright, hard and high-contrast. It doesn't hide anything. The fog and rain that had done so much of the atmospheric work were gone.
A new palette, and a new tone
Roe and the directors didn't fight the light. They used it. The sixth season leans into desert locations, sun-bleached suburbs and the particular loneliness of a well-lit place at night. The colors move from greens and slate grays toward ochre, amber and hard blue sky.
The writing moved with it. Season six is among the most playful in the show's history, with episodes like Triangle, Monday, Arcadia and The Unnatural. It's hard to say whether the setting changed the tone or the tone was already changing, but the two clearly reinforced each other. A show that had been about what hides in the dark found a new subject in what hides in plain sight.
Roe's work was widely recognized. He won ASC awards for Drive in 1999 and Agua Mala in 2000, and received Emmy nominations for The Unnatural and This Is Not Happening. He later shot the 2008 film I Want to Believe.
Going home
When the series returned in 2016, it went back to Vancouver. The tenth season was shot there in the summer of 2015, and the eleventh followed. For a lot of viewers, the first shots of wet forest were as much a part of the reunion as the cast.
A note on frames
Anyone watching today should know that the image they see may not be the one that aired. The series was shot on 35mm film, and the HD remaster prepared for Blu-ray went back to the original negatives. In doing so it reframed the early seasons, originally composed for 4:3 screens, to fill a 16:9 frame, opening up the sides of the image and losing a little at the top and bottom. Accounts differ on exactly when the production began protecting its framing for widescreen, but the later seasons were shot with it in mind.
It's a small difference, but for a show so precise about what it kept out of the frame, it's worth knowing which version you're looking at.