La mémoire des couleurs: le réalisme en question

Les "couleurs mémorisées", différentes des couleurs réelles, influencent les préférences des spectateurs.

Cullen Kelly est un étalonneur professionnel offrant des cours en ligne que je vous recommande vivement. Il possède également un talent certain pour la promotion de ses services. Les e-mails qu'il envoie pour encourager ses clients potentiels à investir dans ses cours sont de véritables joyaux de stratégie promotionnelle. 

Son dernier en date aborde un sujet qui m'intéresse tout particulièrement, parce qu'il remet en question le fameux "réalisme", brandi par une majorité de "fabricants d'images" comme étant le Graal.

Passionné par la magie du cinéma photochimique, Cullen a suivi des parcours atypiques qui l'ont amené à apprendre la programmation, se plonger dans la géométrie analytique ou déconstruire des LUTs ligne après ligne.

L'une de ces aventures l'a conduit à examiner les centaines de brevets publiés par Kodak. 

Cullen mentionne un brevet particulièrement intrigant, "Color Image Reproduction of Scenes with Preferential Color Mapping and Scene-Dependent Tone Scaling". Ce brevet, déposé en 2001 par l'un de ses héros en science des couleurs, le Dr Mitch Bogdanowicz, souligne que la reproduction fidèle des couleurs d'une scène ne suffit pas pour créer une image agréable. Il est recommandé d'opter pour une "reproduction préférée" qui réajuste les couleurs en fonction de leur apparence réelle.

L'un des points marquants de cette recommendation est qu'elle émane de Kodak, dont la mission a priori est de restituer le plus fidèlement possible les couleurs, pour approcher cette chimère - à mon sens - qu'est la réalité.

Je ne veux pas m'étaler trop longuement sur le sujet, je préfère l'aborder sous plusieurs angles dans des posts relativement courts. 

Voici donc un extrait du texte du brevet:

"Il existe un autre type de reproduction des couleurs capable de sublimer les images bien au-delà d'une reproduction équivalente. La "reproduction préférée" des couleurs se définit comme un procédé dans lequel les couleurs s'écartent de l'apparence originale, soit de manière absolue, soit par rapport au blanc, afin de proposer un résultat plus attrayant au spectateur.
Certaines améliorations de couleurs préférées s'appuient sur le concept de couleurs mémorisées. Les recherches ont révélé que notre mémoire de certaines couleurs, comme les teintes de peau (carnations), la verdure et le ciel bleu, diffère des couleurs réelles. Les couleurs mémorisées présentent souvent des nuances différentes et une saturation accrue par rapport aux couleurs authentiques. 

Des études montrent que les spectateurs préfèrent les reproductions se rapprochant davantage des couleurs mémorisées plutôt que des couleurs réelles. Plusieurs chercheurs ont tenté de déterminer les positions optimales de ces couleurs lors d'expériences psychophysiques contrôlées. Cependant, les résultats sont souvent contradictoires, et il a été démontré que les préférences en matière de couleurs peuvent évoluer avec le temps, à mesure que des systèmes offrant des gammes de couleurs plus étendues deviennent disponibles. Le concept de couleurs mémorisées n'a jamais été intégré systématiquement dans la conception des systèmes de reproduction des couleurs."

https://patents.google.com/patent/EP1158779A2/en

Dans sa pratique professionnelle, Cullen insiste sur l'importance des looks pour améliorer l'esthétique globale des images. Il a même écrit et présenté un article sur le sujet lors de la conférence annuelle SMPTE. Selon lui, les looks ont autant d'importance, voire plus, que les ajustements effectués sur chaque plan individuellement. C'est la raison pour laquelle il commence toujours un étalonnage avec un look solide en place.

Ce sujet des couleurs qui "font vrai" au détriment des couleurs réelles ne concerne pas que l'étalonnage, mais interroge notre attitude qui consiste à viser l'objectivité plutôt que d'assumer nos subjectivités.

https://cullenkellycolor.com

Sa chaîne YouTube: https://www.youtube.com/@CullenKelly/videos

Capturing Moments Like a Butterfly Hunter: An Interview with Sander Vandenbroucke

Tamino is an exceptional artist, but what brings me to talk about him here is his videos' beauty and visual consistency. One of my favorites is "You Don't Own Me", filmed by Sander Vandenbroucke. The Belgian cinematographer agreed to answer a few questions.

His motto: "What the camera sees at a specific moment is much more important than how the light hits the scene."

The interview was conducted in English; a French version will be published shortly.

First of all, how did you come to work on three consecutive Tamino videos? 

Tamino came in 2022 with a new album, four years after the successful Amir in 2018. Two friends of his, Bastiaan Lochs and Jonathan Vanhemelrijck were working on his unique visual language - it needed to be more than just a music video. After the success of Amir and, of course, the Covid crisis, artists like Tamino had the urge to communicate more than just music with the audience. 

We started working on "The First Disciple" because this is the album's first single. After a long pause, we wanted it to show the evolution Tamino has been through both as a person and as a musician since then. That video was heavily choreographed because we wanted to shoot in long takes. 

The second video, "Fascination" - which is my absolute favorite - was shot in Spain in the area of Zaragoza. Shooting this was so much fun. It's an ode to Jim Morrison's 1969 film HWY: An American Pastoral. For me, this music video is really about feeling free.
Every time I watch it back, it gives me the same energy as when we were shooting it.

The expression "lensing" a film is very appropriate in your case, as the choices of light and optics seem inextricably linked. This is especially striking in "You Don't Own Me" but also in "Fascination".
In "You Don't Own Me" how did you coordinate your work with the Art Direction, Tamino and the dancers to achieve this visual seamlessness?

The quality of "You Don't Own Me" comes from the choreographer Sidi Larbi Cherkaoui. He knows best how to express and translate ideas with dance or movements. He knows the camera's position and always corrects the choreography from that angle. Working with Sidi Larbi was a relief because he never stops and always looks for ways to improve the shot. 

I think this search to go further where most people stop is what brings the magic into the video. With Bastiaan and Ramy, who co-directed this one, we locked some directions because we were limited by the sandhills in that house. It was 45 tons, though…

Our Steadicamer, Charly Vandedrinck (who also worked on "The First Disciple"), made very precise moves and delivered nice shots. Everyone is always very focused on Tamino's set because wanted to make something special. It needs to be done at that very moment…

That said, I believe in deep and long prep. One of the results is concentration on the set to make the idea happen. That same concentration helps us to see new things while we shoot. These moments are the best.

What is your favorite way to work if you had to choose: lighting for pre-established compositions or framing in a pre-established light?

Definitely the second option (if the light is natural or available). The more I shoot, the more I believe 'light' is a tool. What the camera sees at a specific moment is much more important than how the light hits that scene. A well-chosen camera position elevates the tension in the frame, connects people in a composition, and you visualize the unseen. 

As a cinematographer, I always try to motivate the director to search together and find the most interesting frame. How is the camera moving with the actors? Where is the camera? It's really about exposing the drama with framing I think, and light helps with that. Light itself should never overrule that. 

Sometimes it happens that the director has other opportunities and doesn't feel like searching too much. In that case, I make the light nice – but that's decorating the scene. I don't get my energy from lighting for pre-established compositions… being a cinematographer is much more than that. 

My relation to light is a more natural connection. I just love natural and available light.

There are many slow-mo shots in these videos. How do you determine the framerate on set? Or do you shoot everything slow-mo and let the editor choose? What is your favorite framerate?

Tamino's music has a melancholic vibe. Shooting in slow motion sometimes was more an intuitive choice than a calculated one. Stopping or stretching time fits his way of making music, I think. We shoot most of the time in slow motion and let the editor decide whether it works or not. My favorite speeds are 24, 25, 33 and 1000fps.

Do you follow up on your images during color grading? Are you familiar with the grading possibilities, and how does it affect your work on set - framing and lighting-wise?

I try approaching the image in my head as closely as possible on set. Meaning I try to get the light, colors and contrast right, so there is only improvement in grading and no big corrections. Before we start shooting, I make a board with light directions, I talk with the director about these looks, and when we are on set, there are almost no discussions anymore. 

I try to think about many different looks and go far in the light concepts. It's always easier to take some steps back from an advanced idea. Grading is fun. I always try to be there, know the technical possibilities, and know the points of attention on set.

For example, whenever the skin tones aren't right when shooting, you'd better correct it immediately because it's always a disappointment when you try to correct it later in postproduction. 

Your Insta and website have a mostly poetic and ethereal visual style. Who and what are your influences?

My influences are changing all the time. For now, it will be the photographers Bill Henson, Alex Webb, Jack Davison and the Spanish painter Joaquin Sorolla. 

Paseo a orillas del mar - Joaquin Sorolla

But also Charlotte Wells, Steven Spielberg, and great Italian filmmakers like Antonioni, Visconti and Bertolucci. 

Further, I try to keep my eyes open and see everything as an influence around me. It's better than being locked into the iPhone. Sometimes I use a memory of something specific as an influence too.

Right now, what are your favorite light sources, and why?

6K HMI fresnel and PAR. With these sources, I can do everything actually. I love hard light that can be used on faces and deliver beautiful shadows.

And what about your favorite lens?  

I don't have a favorite lens. But I use my Canon 50mm "Dream" lens, rehoused by TLS, a lot lately!

Do you have a personal project, independent from your cinematographer's assignments?

I'm always carrying a still camera with me. Having a camera wherever I go forces me to look out for pictures, even in very boring situations. I think it's good training for the eye. 

I suppose the search itself will always be a big, if not the biggest, part of my work.

___

https://www.sandervandenbroucke.com

https://www.instagram.com/sandervandenbroucke

https://www.truelens.co.uk/50mm-canon-dream-lens-f0.95