User Guide - Film Emulation Tools
Digital tools for true analog film color
There are two interconnected components that define the look we love about and associate with analog film.
- Film Color - responsible for the deep and rich tones of color negative and slide film
- Film Texture - the structural properties of an emulsion like grain, acutance, softness and halation.
The film emulation tools in Color.io have been designed to match these properties of real film to a very high degree of accuracy. Much higher than most LUTs or plugins in other engines and there's a simple technical reason for this that is deeply embedded into the design philosophy behind the color engine driving Color.io.
Analog Color Science
Color.io uses a an approach to color grading that is deeply rooted in the mathematical principles of film. Traditional film emulation LUTs are often created from sampled data and act as a "black box," meaning they apply a set of color transformations to an image without allowing for any modification of the individual parameters that define those transformations. These LUTs attempt to emulate the response curves of film to light, but they offer very limited control to the user.
In contrast, Color.io's engine uses what could be considered "film-derived math" approach. This means that the color grading tools in the app simulate the non-linear light response of film, with each control driven by this underlying model. Color.io uses thresholds, luminance weights, gamut compression curves and channel cross-talk properties that have been derived from real film sample data. But instead of just packaging these data into 3D LUT containers like traditional film emulation approaches, these data points are implemented as magical constants in the color science framework driving all tools in the app. This is why every parameter in Color.io behaves as though you were working with an analog emulsion as opposed to binary digital data. Colors are richer, with more depth, and stay clean even when making big sweeping changes to the palette. This granular control and the exceptional color stability allow you to recreate the look of slide film or the color depth of color negatives without being confined to a black box.
Insider Knowledge: Film data sampling and aggregation has been an effort spanning multiple years. VisionColor sampled a large number of still photography and motion picture film stocks between 2012 and 2014. 5 color negative stocks from the Kodak Vision3 family were re-scanned on an ArriScan XT @6k resolution in ultra-wide HDR color in 2021. The data from these new film samples, which were originally intended to be packaged into a new LUT library (ImpulZ 2.0) has instead been integrated into the color processing framework at the heart of the Color.io engine to enable users to create their own film looks based on true film derived constants.
Film Texture Emulation
For film texture emulation, Color.io allows you to add realistic film halation to the highlights of your digital images. The volumetric grain tool in Color.io does not simply overlay a grain texture over your image but rebuilds it, pixel by pixel, from 3D granules that are hard to tell apart from real film. Film emulsion softness and acutance (sharpness) are simulated by adjusting the grain-packing density to fundamentally alter the pixel structure of digital images to resemble a true analog film base.
With Color.io you can edit images and build 3D LUTs with a powerful online raw developer and analog film look designer for photographers and filmmakers. Craft stunning film color in record time that works for any camera, in any software and on any device, directly in your browser.
