By Iain Blair

Directed by Christopher Nolan, and based on the novel “American Prometheus,” Oppenheimer tells the story of theoretical physicist J. Robert Oppenheimer and follows the work of his team of scientists during the Manhattan Project, leading to the development of the atomic bomb. It stars Cillian Murphy as Oppenheimer.

It also features VFX depicting everything from the first atomic test in the New Mexico desert to physical phenomena ranging from subatomic particles to exploding stars and black holes. As the film’s sole VFX partner, Dneg delivered over 100 shots, crafted from more than 400 practically shot elements, to help create some of the film’s most important and explosive sequences. Oscar-winning production VFX supervisor Andrew Jackson, and Dneg VFX supervisor Giacomo Mineo led the team. Here they talk about creating the VFX and how they did it.

Andrew Jackson

What were the big challenges of creating the VFX for this?
Andrew Jackson: One of the biggest challenges, which was also one of the most rewarding aspects of the work, was the set of creative rules that we imposed on the project. We wanted all of the images on the screen to be generated from real photography, shot on film and preferably in IMAX. The process involved shooting an extensive library of elements. The final shots ranged from using the raw elements as shot, through to complex composites of multiple filmed elements. This process of constraining the creative process forces you to dig deeper to find solutions that are often more interesting than if there were no limits.

Giacomo Mineo

Giacomo Mineo: The movie presented two significant challenges. First, the recreation of the Trinity test and second, the fascinating task of immersing ourselves in Oppenheimer’s mind and figuring out how to capture his ideas and imagination, considering the limited knowledge and visual references available during that era. Concepts like modern physics or the Earth seen from space were relatively new at the time. To truly portray Oppenheimer’s mindset, we had to let go of our modern understanding and delve into his world.

How closely did you work with Chris Nolan? What guidance and input did you get?
Jackson: This is my third film with Chris, and during that time, I have developed a strong understanding of his filmmaking philosophy. His approach to effects is very similar to mine in that we don’t see a clear divide between VFX and SFX and believe that if something can be filmed, it will always bring more richness and depth to the work.

I feel he has a level of trust in my approach to the work, and I really appreciate the freedom he gives me to experiment with ideas and the collaborative approach we take as we refine solutions for the individual shots. As well as having the creative experience from years of working with Chris, Dneg also has a huge benefit when it comes to solving the technical challenges of working with IMAX resolution in a largely optical production pipeline.

Mineo: Chris Nolan was well aware that, without the use of CG, we had a limited set of options. He was flexible and receptive throughout the entire process of exploration and image creation. Whenever he discovered intriguing elements within our tests, he was swift to integrate them into the film and see if he could make them work. This was a really positive and rewarding part of the collaboration.

Also, Andrew played a pivotal role by working closely alongside us, providing the right framework and great creative guidance and bringing his experience and vision to the team.

Is it true Nolan didn’t want to use any CGI? Was that liberating or constraining?
Mineo: This was the challenge set forth by Christopher Nolan, and we embraced it. His vision was that every on-screen image should originate from authentic photography captured on film, preferably in the IMAX format. In pursuit of this goal, we employed traditional techniques such as miniatures, a range of explosions (from massive to micro), thermite fire, long-exposure shots and many more.

The majority of our VFX work revolved around these tangible elements, intentionally avoiding CGI and primarily relying on compositional treatments. This unconventional approach, characterized by self-imposed limitations, had a profound influence on the image-creation process. These constraints compelled us to think innovatively, leading us to creative outcomes that were both distinct and captivating while remaining undeniably rooted in reality.

How many VFX shots are there?
Mineo: There are around 100 VFX shots in the film, plus around another 100 shots that were directly extracted from the vast IMAX library of elements created by Andrew.

How did you recreate the nuclear tests and show the scale of an atomic blast? Break it down for us.
Mineo: For the Trinity test sequence, the goal was to craft an authentically real and awe-inspiring depiction. To achieve this, Andrew and SFX supervisor Scott Fisher embarked on an extensive shoot, capturing a wide spectrum of explosions using IMAX technology. The range included grand-scale detonations featuring various lenses as well as smaller-scale and even underwater detonations. Notably, the billowing dust from the ground and the shockwaves were achieved using small or macro-scale elements.

At Dneg, fully aware of the significance of the task, we began exploring various options right from the first day. We maintained an ongoing dialogue, frequently presenting our preliminary tests to Andrew and Chris Nolan. While archived footage served as inspiration, we allowed for a degree of interpretation, focusing on capturing the essence of the event rather than an exact recreation.

One example is the plasma ball atomic test featured in the high-speed archive footage. To achieve that, we used underwater micro explosions combined with a massive explosion. Subsequently, extensive compositing work was undertaken to seamlessly integrate the elements. Special credit goes to Jay Murray for recreating this iconic moment.

How did you create the crackly rings of fire that Oppenheimer kept visualizing?
Jackson: I built a contraption with multiple spheres, each spinning on different vibrating arcs. These were shot with very long exposures to create the curved, wavy lines.

How did you create elements such as subatomic particles, exploding stars and black holes forming?
Mineo: In the preliminary phase, Andrew dedicated months solely to experimentation at Scott Fisher’s workshop in LA. Armed with his digital camera, he captured a range of tests and presented them to Chris Nolan for review. These tests encompassed a mix of old-style techniques, including miniatures, minute explosions, thermite fire, spinning beads and much more.

Upon Chris Nolan’s approval, the production transitioned to filming in IMAX format. The outcome was a compilation of hundreds of distinct elements. While some seamlessly aligned with the script’s narrative and found their way into the edit, many others contributed to a vast library of elements. Subsequently, for portions of the script still awaiting attention, we embarked on exploring these recorded elements, aiming to complete the work exclusively with this material.

Throughout this process, we discovered that simplicity often yielded the most effective results. However, for instances like the chain reaction or implosion/explosion shots, we employed a diverse assortment of elements, always mindful of preserving the raw authenticity of the footage. Our goal was to maintain the sensation of genuine photography captured on film.

What was the toughest sequence to deal with and why?
Mineo: Without a doubt, the Trinity test was one of the most significant challenges. This was arguably the most complex task of the show, demanding great attention to detail in terms of compositing. It encompassed a range of elements, from massive explosions made in collaboration with Scott Fisher, to relatively small and macro elements shot at the highest frame range IMAX allows.

Examples include tiny, sandy shockwaves and underwater churning dust, to name just a couple. It is worth noting that in the film, the depiction of the explosion from various perspectives was realized through a combination of techniques, including the retiming of practical large-scale explosions and the intricate process of compositing extensive practical elements together. The “wall of fire” shot, designed by Peter Howlett, is an example of that brilliant type of work.

What gear did you use? Any new or cutting-edge systems and methods?
Jackson: We used old-style practical effects methods and techniques, perhaps “cutting-edge” in their era.

You’ve both worked on a lot of huge projects. Where does this rate in terms of complexity and challenges?
Jackson: The approach for this film was so unique that it’s difficult to compare with other projects. Some of the biggest challenges for me were during the shoot. We had a very small IMAX film unit working alongside the main unit in New Mexico, in the winter, in a tent. We needed to move the whole setup every few days, and the weather conditions were less than ideal — we were dealing with snow, freezing water tanks, mud, wind and rain.

Mineo: Undoubtedly, this project stands as the most distinct and extraordinary endeavor I’ve been a part of. We were in full creative mode from the beginning to the end. All the work relied on us embracing the set of rules imposed from the beginning and thinking out of the box.

Our days were really spent looking at the elements, in constant exploration, trying to find something interesting that could be utilized in the movie. The process of continually experimenting with ideas involved creating numerous images, with some eventually making the final cut and others not. A notable illustration of this creative approach is the “birth of the star” shot, designed by Ashley Mohabir. In this instance, we combined a thermite fire element, slowed it down and merged it with a starfield look element coming from the underwater metal particles shoot. The outcome was a striking image that resembled stars and the cosmos.

Images Courtesy of Dneg © Universal Pictures. 

Industry insider Iain Blair has been interviewing the biggest directors in Hollywood and around the world for years. He is a regular contributor to Variety and has written for such outlets as Reuters, The Chicago Tribune, The Los Angeles Times and the Boston Globe.