The Science and Technology Council (STC) of the Academy of Motion Picture Arts & Sciences (AMPAS) development committee has been working on a new colour science for motion pictures since 2004. Academy Colour Encoding Specification (ACES) is a new technological development designed to streamline post-production and finishing.
ACES was built on more than 70 years experience of film development, 15 years of Digital intermediate and over 5 years of refining.Today we are given access to three proposed standards, which essentially means that we now have the ability to work with colour space that is infinite. ACES takes into account the whole visible human spectrum and is encoding colour at precision of 1024 steps per each stop with over 30 stops of available dynamic range.
My interest in ACES has been from day one, but it was only a year ago that I was given access to the industry’s first and then still ‘beta’ version of Davinci Resolve with ACES implementation. These early tests were very promising but practicalities of working in ACES were not quite there. It took many hours of testing, measuring and close work with development teams, and one step at a time we worked our way through it. In may 2012 I completed my first successful ACES job, a short piece for IMAX, shot on F65.
In early summer 2012, I was approached by DP Steve Marshall from Brunswick Films and director Paul Emmanuel to grade their indie ‘The Maid’. The film is coming of age drama about emotionally troubled young man who gets into a relationship with an older woman. It was shot on location in Richmond using RED EPIC and production certainly had luck with the weather as most early rushes that I have seen were shot on sunny days. Inspired by the story and the lead’s French accent, I looked in the direction of French Cinema for reference looks. After selecting a few favorites it became obvious that I was best connecting with films that were finished photochemically and all but one shot on Fuji stock. I was after a very simplistic look with pastel tones and light and airy shadows that would further enhance shallow depth of field, particularly the dialogue scenes that were calling for lightness and sensuality. These colours and tones are an essential part of the story as they give hints of erotic charge between the actors, and allow the emotional state of the actor to be expressed, such as fear or shock, passion and relief.
I’ve found the look that we are getting out of the camera was miles away from the desired look; this was especially true for the capture of green hues. All the grass and trees looked electric green, almost radioactive and had none of that lushness and richness that I was after. And then came the issue of skin tones; it seems that digital camera manufacturers in the war of higher dynamic range completely focused on highlights and shadows, ignoring the importance of mid-tone curves. As a result, it can at times be quite challenging to be as precise as desired when it comes to the skin tones. It became apparent that in order to achieve the look I was after, I was best to resort to ACES.
Digital image is traditionally packed in 10-bits files, which gives 1024 steps for each stop, for total dynamic range of 12 stops, with this level of control, one can push one pixel into certain direction only so far, before it starts ‘screaming’. Simply put, we are limited by how far we can change a pixel from its neighbouring spectrum before it gets noisy or it starts distorting. The beauty of ACES is that it largely removes this limitation and we have greater precision, elasticity and flexibility when it comes to adjustments.
Another feature of ACES is that in order to work with it, there is nothing special that needs to be done to the camera. One can just use RAW camera data as usual and move into ACES at the finishing stage.
However, before fully setting on the course of ACES, we had to overcome few more technical hurdles. RED’s implementation of ACES is not complete and is not part of their SDK but I found the way how to move RED RAW data into ACES as a pre-grade and conform process. Once we overcame this hurdle, we had to deal with the issue of colour fringing; slightly visible bayer pattern on gradients and all too annoying noise. This is usually very subtle and only mildly apparent in normal 10-bit finishing, but now in ACES, it really bothered me.
For that reason I developed a new set of filters and pre-processing algorithms that I applied dynamically to RED RAW before moving it into ACES 16-bit files. All with great success, and all the extra effort in pre-grade completely paid off.
If one year ago my first contact with ACES was love at first sight, today, I must admit, I have developed serious relationship with it. With its great similarity to film printout process, and its high fidelity and precision, it made it all worthwhile. Perhaps most importantly on a creative level, it has taken me back to early days of very minimalist and simplistic approach to look building and creation. Almost 80% of movie ‘The Maid’ was done with not more than one primary grade and one power window with hardly any secondaries throughout the film. I have found myself using more and more printer lights again. In my opinion, the images we get with ACES are nothing like we have seen before from any other digital workflow; I believe ACES has the potential to be the single best development in colour grading that we will see.