NAB Panel Session IMAX “Futureproofing for 8K since 1972
At the NAB Show in Las Vegas in April 2025, the 8K Association hosted a panel session titled “8K Technology and its Emerging Role in the Creative Process”. After a brief introduction by Robin Raskin of Virtual Events Group which coordinated the events in the Creator Lab Theaters, 8K Association Executive Director Juan Reyes welcomed visitors.
Reyes started by highlighting the growth in the ecosystem of capture, encoding, decoding and displays. However, the talk was about the creation and development of 8K.
Reyes introduced the speakers:
- Greg Ciaccio, VP, Post Production Original Content & Image Capture for 8K Association member company, IMAX
- Michael D. Smith of Wavelet Consulting LLC, who has been a contractor to Warner Bros for around 20 years.
Ciaccio explained that his role is really to ensure that the creative intent of those making content for IMAX is maintained through to the final viewing. Smith said that his focus was on image quality, compression and intellectual property. He looks at new formats and working with industry groups such as SMPTE. He has been involved with scanning of Warner Bros film-based content.
Ciaccio dug into IMAX’s 65mm film format which is the biggest ever devised and the firm scans at 8K or more and has been doing so for twenty years or more. It has been a challenge as there are few suppliers of appropriate equipment, although the firm has recently bought a new scanner.
He explained that the film-based screenings of Oppenheimer were made using prints directly from the cut negative – there was no intermediate print or negative, so the quality was as high as possible. Even though DCI (for digital cinema) is limited to 4K and delivery to the home is at 4K (or 8K soon, he added!) the aim of the firm is to preserve the original resolution as well as it can.
Smith explained that Warner Bros has about 8,000 films in its archive and in recent years, around 500 have been scanned in 4K or 8K. 8K scanning started around three years ago and about 20 films have been through that process. When the negative is used for this, Smith said that the film is treated as though this is the last time that the negative might be touched, because “things happen”. Scans can be made for preservation or to create new masters. Tests are done of several scenes in 4K and 8K to see if there is a difference in ‘blind tests’. The additional file size and storage expense of 8K is justified if there is a visible difference.
Oversampling Works for Dirty Harry
Reyes asked about the recent announcement of an 8K scan of Dirty Harry. Smith said that the tests showed that the negative would benefit from 8K scanning and this was done with the Lasergraphics Director scanner. Reinforcing the point about oversampling, Smith said that a better 4K master could be made after 8K scanning. As he said “Oversampling works”.
Smith dug a bit deeper into the technology. With film, he said, the resolving power is about 80 line pairs per millimeter. With the 25mm of active film width on 35mm film, you can get around 2000 line pairs. At the Nyquist rate. you would need 4K and to get oversampling you would go to 8K or perhaps 6K. With 65mm. you have around twice the active width so you need around 8K samples per width – to oversample you have to go beyond.
However, not all content actually has that resolution – it can depend on the lenses used or the film stock, as processed, may not be able to resolve to the maximum. It’s not a “One size fits all” solution.
IMAX Explains its 10X Area Advantage
Ciaccio explained that when you see 70mm film, the format actually delivers 70mm width which is ‘5 perf’. However, IMAX 65mm format is run horizontally through the projector, so you. are seeing ’15 perf’ film area, or around ten times more surface area.
IMAX is currently working on the “Chapter 51” title, clips of which were being shown on the 8K Association booth at the show. Ciaccio explained that Tyler Shields who has been making the film is better known as a still photographer. In Chapter 51 he used almost all the different film formats ever used.
Ciaccio said that one day when a film maker was in the mastering suite, he was surprised at the quality of the images being shown. “I’m shooting 8K all the time, but it doesn’t look this good”, the film maker said. Ciaccio showed him a film strip to highlight the large capture area of the film and told him that the film was shot thirty years ago.
“We were future-proofing for 8K since 1972”, he said.
Better Pixels as Well as More Pixels
Smith explained that camera-based scanners, like the Lasergraphics Director, can use multiple exposures to capture more dynamic range from the full density range of scanned film. That means not just more pixels, but better pixels. Warner Bros was able to use this technique to create an HDR version of the Purple Rain film that is also used for the 4K Blu-Ray.
HDR can make noise more visible. That can be from the film grain in the content and from the digital sensor in the scanner itself. Smith explained that multiple exposures could also be used to minimize noise from the scanning process. Sometimes, more grain is used with a creative intent, for example to highlight a flashback. In other cases “dreamy” scenes may have very small grain so that the look is different. Ciaccio agreed that multiple flashing of the image could be useful.
Clean-up of films from dust and damage can be time consuming and sometimes, as with recent music documentaries from IMAX, the firm didn’t create the original content, so it is of mixed quality. IMAX has developed what it calls the DMR restoration process, which is AI-based to optimize the output. DMR reduces grain and noise and the process is operated in a full-size theater, with the creatives, to ensure the look is true to the intent and will be the same for viewers in IMAX’s premium theaters.
“These decisions can’t be made on a 75″ screen in a small room”, Ciaccio said.
DMR techniques is also applied to home content, but the way it is done may be different.
8K Scanning of “Ben Hur” and “2001”
Smith explained that as 8K was most likely to be appropriate for 65mm film-based content, “Ben Hur” was scanned that way. One of the first titles to be scanned in 8K was “2001: A Space Odyssey” which was scanned in 8K so that NHK of Japan was able to broadcast the title on its 8K channel.
Work Towards an 8K IMF Format
Smith explained that he is working on a new version of the IMF format for the delivery of content. At the moment, that format is limited to 4K but is being extended. (IMF is a format for the delivery of content ensuring that all versions of a piece of content are available, but with minimum duplication). The updating is being organized through SMPTE and is intended to support the delivery of 8K scans.
Reyes highlighted that this change demonstrates the continuing improvement in the 8K ecosystem which is important to preserve film assets.
Reyes asked about clean-up costs in scanning and between 4K and 8K scans. Ciaccio explained that IMAX uses a layer-based approach and that you can simply take the work done on the 4K master and apply it to the 8K version. It’s just processor time and storage that is different, he said. Cloud-based approaches make this simpler.
Development Continues
Smith said that Warner Bros would continue to develop scanning at 8K and even the 13,5K that the Director can support. Ciaccio explained that in the new title, “Sinners”, a deliverable had been made at 4K, but a decision was made to zoom in by 25% at one point. Because of the higher resolution of the master, this became a simple process without the need for a re-scan (and filmmakers hate to have their film touched).
Ciaccio highlighted that home TVs are getting bigger and cheaper every year with 100″ TVs now readily available. He also said that it’s not about ‘counting the pixels’, that the key point was the feeling evoked in the viewer by the content as it is presented. “If you can see the pixels, that’s really bad” he said. He highlighted that film doesn’t have pixels and that IMAX wants deliver more immersive experiences.
Reyes explained how the 8K Association had commissioned a White Paper last year that digs into the issues of immersion and how 8K can deliver high detail and immersion at the same time.
Smith would like to see better lenses as it can be frustrating when a poorer quality lens is used with a very high resolution sensor. Unless the lenses are good enough, you won’t see the difference. “It’s all about the MTF”, Ciaccio commented.
He also added that better codecs will help,
“We don’t want to squeeze 8K down a 4K pipe”.
With that, Reyes thanked the panellists and invited everyone to the 8K Association booth to see great 8K for themselves.
Ciaccio highlighted that
