How Oppenheimer Reinvented Imax

INTRODUCTION

There’s a famous saying that ‘life imitates art’. 

I’d say this rings true for the process of creating Oppenheimer - where the story of a team’s struggle to push the bounds of science to create a new technology was mirrored by the film crew’s very own push towards creating new Imax camera tech to tell that very story.

This included advances in lighting, lensing as well as the creation of a new 65mm black and white film stock. So, let’s break down some of the technical advancements that influenced the visual storytelling in Oppenheimer.     

HOW IMAX WORKS

If you’ve seen this film in an Imax cinema it’s difficult to deny that Imax is a truly gorgeous format. What makes it different from shooting on other camera systems is the size of the negative that it captures images on. Basically Imax takes the image capture area of a traditional 35mm camera and supersizes it - flipping the 65mm film sideways to create a negative that is over eight times larger.

This gives Imax footage an unprecedented resolution of detail, low film grain, a wide field of view and makes it possible to shoot with an extremely shallow depth of field - that can give close ups and wide shots alike a very blurry background.

However, pushing the bounds of photochemical image capture comes with a number of downsides.

WHY SHOOT ON IMAX

But, before we delve into these issues, why shoot what is effectively an intimate, dramatic portrait of a character on Imax in the first place? 

Well, director Christopher Nolan and cinematographer Hoyte Van Hoytema like to first begin by identifying the creative needs of the project, then start unpacking the technical solutions and innovations that they can come up with to make those artistic decisions a reality. 

In the words of Van Hoytema "Large format photography gives clarity and places the audience in the reality you are creating for them." So, Imax was used as a creative solution to immerse the audience not only in the action sequences and setpieces, but to intimately envelope audiences in the face and performance of the protagonist, and get them caught up in his psychological state and emotions.

Using Imax to capture every nuance of detail on a face, rather than just for aerial landscapes and explosions. 

SYSTEM 65 VS IMAX

However, if you’re observant you may notice that in Oppenheimer, and in fact all of Nolan’s films which use Imax, different shots alternate between a widescreen aspect ratio - with a black letterbox on the top and bottom, and shots with a taller frame.

These two different aspect ratios reflect the two different film formats used to shoot the movie. 

All the widescreen shots were photographed with a 2.20:1 aspect ratio on a 5-perf Panavision System 65 camera, which runs 65mm film vertically through the gate. 

While the taller shots were done on a 15-perf Imax camera that runs 65mm film horizontally and uses the largest possible recording surface area. Either presenting the full 1.43:1 Imax negative, or, in most distribution cases, cropping off the top and bottom to get to a 1.90:1 ratio.

Some scenes even intercut between these two different ratios. Why is this? Why not just shoot everything in Imax? The answer is because of sound.   

SOUND ISSUES

Running so much film through the Imax camera so quickly means that it makes a huge noise. This gets picked up by the microphone that records the dialogue on set.  

So if you watch a few scenes, you’ll notice that any moments with dialogue tend to be shot in a widescreen ratio on 65mm with the quieter 5-perf camera. While other moments without synchronised dialogue that can be covered up by sound design,  ADR, or even denoising audio in post, are shot on the noisy Imax camera. 

Sometimes Nolan even cuts from reaction shots filmed on Imax to dialogue shots filmed on 65mm during the same scene. 

CUSTOM LENSES

Another technical snag they ran into stemmed from Nolan wanting to visually present Oppenheimer's abstract idea of what was happening on a subatomic level. 

Again, they started with the creative need - shooting practical microscopic visual effects - and from there came up with a technical solution that involved creating a new, custom prototype macro snorkel lens for Imax.
This was designed by lens aficionado Dan Sasaki at Panavision who was tasked with custom engineering a waterproof, wide angle macro lens. He managed to produce a 24mm and a 35mm - with the 24mm lens being able to focus within a ridiculous 1mm from the lenses front element.

Part of the reason why these lenses didn’t exist before and why they were incredibly difficult to produce is because Imax glass needs to be very wide in order to avoid vignetting - seeing inside the barrel of the lens - which creates black circular edges around the image.

The solution to this is to make the diameter of the glass elements larger. However, because it was a probe lens there was a restriction on the width of the elements. Sasaki managed to solve this by adding an extra five glass elements inside the barrel of the lens.

Creating this new lens resulted in some spectacular practical effects. Slow motion, 48FPS, Imax macro shots of spinning beads on a wire rig and burning thermite which were shot underwater in a tank - which they hit with a single, strong, hard light source.  

For some extreme slow mo shots they also used a 35mm Arriflex 435 - which could shoot at a higher frame rate of 150FPS.

NEW FILM STOCK

Like his early film Memento, Oppenheimer uses black and white and colour as a way to delineate different timelines and perspectives within the narrative. Nolan went so far as to write whether each scene was in black and white or in colour in the screenplay.

Again the starting point was the creative decision to present Oppenheimer’s perspective by using colour and another character Lewis Straus’ perspective using black and white. 

Once again this led them to a technical snag. Kodak had never cut and finished their Double-X 5222 emulsion in 65mm before. It had only been produced for 35mm and 16mm.

Double-X has lovely contrast and a strong dancing grain in the midtones which is much more pronounced than were they to shoot on colour Vision-3 stock and convert it to black and white in post. 

So, with some work, Kodak managed to manufacture their film stock in the larger gauge size that was needed for 5-perf as well as 15-perf Imax for the first time. 

It also meant that a change needed to be made to the Imax camera. Because monochrome negative has a different backing than colour negative’s remjet layer, it created various exposure artefacts and scratches due to the polished chrome pressure plates that came into contact with the film inside the Imax camera.

To fix this Imax manufactured a custom ‘black oxide’ vacuum pressure plate that eliminated the issue. 

Fotokem, the film lab that processed the black and white stock also had to adapt. They spent three days shutting down their 65mm colour development equipment, cleaning and converting it to the chemicals needed for black and white.

This turnaround meant that the production had to schedule around shooting all the black and white scenes - sometimes waiting up to a week before being able to view the processed rushes.

TWO VISUAL APPROACHES

On top of presenting the perspectives of the two characters in colour and black and white, Nolan and Van Hoytema also employed other cinematographic techniques to do this.

If you look at this scene and this scene you can clearly see through the use of shot size and angles whose perspective each takes on. They use close ups of the character of importance, followed up with over the shoulder shots, taken from their perspective to put the audience directly in their shoes.

On top of this, they more often used a handheld camera and a wider angle 40mm or 50mm focal lengths to shoot the more uninhibited Oppenheimer. While using more static, composed shots on a longer 80mm lens to shoot the more calculated Strauss.    

LIGHTING INNOVATIONS

The team’s technical innovations weren’t limited only to the camera, but also to the lighting.  

To save time and give them the ability to dial in specific colour and brightness values, van Hoytema’s gaffer rigged the lights with latency free transmitters and receivers that fed to a DMX board. 

This meant that the electrical team could rig the lights, then van Hoytema and his gaffer could be on set and adjust all of them by dimming, adjusting colour temperature or even RGB values, from the DMX board. Even if the light was rigged blocks away. 

This was useful for perfectly balancing and matching up the colour balance of the artificial light sources with the natural light that was coming from the same direction. 

Like all the other technical decisions, the lighting was also influenced by the story. Most of Oppenheimer’s scenes were lit with slightly softer light sources like LEDs or HMIs that were diffused, while the black and white sequences of Strauss were lit with much harder, direct light from old tungsten units. 

CONCLUSION

I think what all of these innovations show is that technical breakthroughs come as a result of needing to fulfil a creative choice - not the other way around.

Nolan and Van Hoytema first come up with the best visual ideas that serve the telling of the story, then from there treat it as an engineering exercise, assembling the best team that they can to innovate and invent the best technological solution.