THE Infrared Cinematography OF “Dune 2” - Everyone Wants to Know
With the recent theatre release of Dune 2, viewers and cinematographers alike have been stirring over the gladiator scene. For the majority of the film, the prevailing color of the film exhibits purely warm & sandy colors of the desert. Then, along comes this fight scene which is shown in total gray-scale, a term used to describe imagery that is devoid of any colors other than white, black & the grays in between. Gray-scale is defined as the color white at one end, black at the opposite end and various shades of gray in between.
It's fair to say that the average movie-goer watching this fight scene would see this as a sequence that was shot in black & white, possibly as an artistic choice made by the person operating the camera - for emotional or perhaps for cinematic effect. Well, both are true but the real goal for this scene was to create much more than a gray-scale image. What the layperson wouldn't recognize is the beauty of Infrared (IR) Image Capture.
Why infrared? IR imagery is so much different that normal black/white insofar that it offers:
High levels of Contrast (Ratio of black to white)
Very high image detail (the principal reason why IR is used in security cameras)
Glowing Highlights
Deep black night skies
Unsurpassed tonality
Infrared Theory in Digital Cameras
Firstly, a bit of theory/history about digital cameras (CMOS Sensors.) With the advent of the digital sensor, it was found that, unlike film which could barely process all wavelengths of red light and saw no infrared at all, the digital sensor would abundantly process infrared wavelength light. It turned out that this IR light was infiltrating (polluting) color imagery and the black colors were turning to brown. This was particularly evident on textiles - velvet and cotton were some of the worst where blacks would turn into chocolate/maroon colors. This phenomenon was also called, "Infrared Leakage." It was this very leakage that caused the need for IR absorbing Neutral Density (IRND) filters. It was circa 2011 that the first IRND filters were introduced into the filter market to solve the problem caused by the offending infrared. The camera manufacturers' solution to this leakage problem was the employment of the OLPF (Optical Low Pass Filter.) What this means is that wavelengths of light that were considered short or low (indigo and on through mid-red colors,) could pass freely through the filter but long/high wavelengths (including infrared) would be absorbed by the OLPF. The OLPF is mounted on the sensor and can be removed fairly easily in most cameras.
The Setup
Two key components of the IR capture are:
1 - Camera with OLPF filter removed
2 - IR Pass Filter
With the OLPF removed, all wavelengths of light from upper ultraviolet (350nm) up to near infrared (1000nm) can freely transmit into the sensor for processing. The issue here is that visible & UV light are also permitted to pass as well - and must be stopped, or the image would not be gray-scale. The IR Pass Filter allows the IR to pass but absorbs all visible light and the bit of UV as well. It is with this setup that only the IR can be imaged - nothing else.
Films that employed infrared
Ad Astra - IR 1000nm was used on a 4-5 minute scene on the moon's surface. The glowing whitish gray color of the surface against the pure black sky was a demonstration of superior contrast. Of course, this was a complicated sequence as yellow light was introduced into the image to represent light from the sun that would shine onto the moon.
NOPE - This film employed IR 1000nm filtration + plus a second camera blending two images into one to achieve "Day for Night" imagery. The infrared coupled with the true blue-green color of nighttime from the second camera, served to produce spectacular detail that would otherwise be lost if not shooting IR.
Dune 2 - Look at the tremendous contrast between the glowing scalp vs the black background. In the shot below, look at the detail in the lower lip. This could never be captured in normal black/white mode.
Summary
As stated, in recent years, three films have utilized this novel technology. When we say novel, that is not to say that infrared imagery is new to the world of image capture. In fact, infrared acquisition is as old as the hills - in still photography. However, it is very much expected that this technology in cinematography has just begun. So many have been testing infrared in many ways. What is to come can be considered very exciting!!