Mindhunter, the show about the early days of the FBI's behavioral science unit, is back for its second season and it is just as fantastic as ever. Not surprising as it has David Fincher (who also directed a number of episodes) as its showrunner. Fincher has a reputation for producing good, detailed, and highly engaging thrillers.

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This is partly achieved for his genius use of very subtle CGI. Of course given that Fincher cut his teeth at Industrial Light and Magic (the company that pioneered all the effects for Star Wars) it shouldn't be surprising that he knows how to use it well. CGI is mainly used to create creatures and set-pieces Fincher uses in service to the story, the information you need for the scene, and to add an extra layer of authenticity. Mindhunter is littered with CGI that purely exists to inform your viewing pleasure.

Color Of Grass

Period detail can take a lot out of a television budget. Depending on when it's set, however, a show can get away with accurate costumes and a few props. Fincher, however, uses CGI to save on set dressing and to more authentically place the audience within the setting. Many of the subplots of Mindhunter take place in the suburbs of America, which at the time were still recently built (compared to today). Using CGI to change the color of grass and trees to make them look fresher and younger is a subtle but effective way of breathing life into a location that would be noticeably changed by age.

Changing The Weather

Weather on film is just as vital to storytelling as it is to setting. Elements such as rain or snow are one of the few things you can guarantee an audience can relate to sensually. While we may not know what it's like to be an FBI investigator, we know how cold it can be to walk through a snowfall. It's a key detail for giving us a way into how a character may be feeling in a given scene without having to spend time establishing it with dialogue. Waiting for the right weather can take time, but not when you can choose to add it in digitally.

Removing Film Equipment

Filming TV is notorious for how quick it has to be. David Fincher is notorious for how many takes he wants. For one Mindhunter scene, he reportedly filmed over 70 takes. Fincher can afford to do this with CGI. Resetting for each take takes time, but not if you don't mind having film equipment in the shot only to digitally remove it later. Fincher can pack in many more takes in a much quicker time because he doesn't have to worry about resetting.

Impossible Shots

In a similar way, Fincher can use CGI to create shots that may not be realistic but are important for the tone of the scene, and it still doesn't affect the authenticity of the show. In one sequence Holden is sitting on his own of an airplane, reflecting on the ordinary lives of American citizens as he literally looks down on them.

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To convey both Holden's isolation as he thinks and the literal millions of lives that are also required for the scene, Fincher puts the actor in a practical set in front of a green screen. This way he can push his camera across Holden and then through the plane window to open onto a completely CGI image of night-time cityscape. A trick you could not pull in real life.

CGI Store Front

From partially digital shots to entirely digital shots, Mindhunter is using every trick at its disposal to make a very well constructed narrative. To show how public some of the murders are Fincher has them reported from TVs on display in a shop. Nowadays these types of shop fronts are almost nonexistent. For one thing, TVs are far bigger and as a culture, we've changed marketing to be more minimal and simplistic. The type of shop front Fincher requires, therefore, doesn't exist so it would either have to be hunted down or constructed completely. As he only needs it for a few seconds, why not just build it entirely in the computer, again it saves production time.

Adding Backgrounds

While some filming locations may still be period-accurate their surrounding may not be. So for example in one scene where the agents are taking a break in a '70s diner, the backgrounds are added in post. Either by taking away modern-day constructions or by completely adding in landmarks. Again it's a trick that makes location scouting easier, the task is reduced to one building, setting can always be changed and added later.

Change The Seasons

So much of Mindhunter takes place on the road, meaning that production doesn't have the luxury of sets. Furthermore, the show takes place over a number of years and part of the story is the way they show the passage of time. However, all the filming has to be done in a much smaller window of time. So for scenes that actually filmed in Winter but are meant to be Fall the trees have leaves added to them and their color changed.

Greenscreen Montages

As Mindhunter has to cover a lot of time the most effective way of showing this is through montage, lots of shots cut together often to show repetitive action. Fincher filmed all montage shots in front of a green screen, again so he could control the different moods each new location would, realistically, give you. America can look and feel very different depending at any given time depending on where you are. Rather than film around Los Angeles and hope no one would notice, Fincher films these simple scenes in a studio so he can later add in the different climates and landscapes of the individual states.

Changing Real-World Architecture

It may seem pointless but in one sequence of Mindhunter, the real-life pavements are altered to be more accurate to the setting. It's very subtle and almost unnecessary. However it's a clever way of exploiting an effect often called uncanny-valley, the expression relates to when the human eye sees something very realistic but can tell it's not. While we may not be able to tell what has been changed the scene does its job by creating a feeling of change, so when we watch a scene one of the main things we'll recognize is it does not belong to our world.

Car Crash

Usually when filming a car crash the most important element to get right is the impact. With limited budget and time, a car crash on TV is often very quick and mainly creates the illusion of an impact. But with CGI Fincher need only film a before and after and then fill the rest in digitally. The crash itself only lasts a few seconds but because you can see it in its entirety the effect is far more powerful. And again it's not an excess: Holden needs to realize how fleeting life can be to better get into the heads of the killers he's investigating and the audience needs to know it too.

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