Digitized film images originating from a datacine conversion process are high-resolution scans that preserve much of a film's resolution and colour depth. In Smoke, a lookup table (LUT) is the primary colour management tool available to deal with different colour spaces. A LUT is an ASCII file used to map pixels or pixel components from one colour to another. To display logarithmic film scans properly, such as Cineon files in the linear colour space native to Smoke, you can work with monitor, display, and image conversion LUTs. You can use one of two kinds of LUTs: 1D LUTs and 3D LUTs. 3D LUTs are available only in Smoke 2K.
Digital film scans often consist of logarithmic data rather than linear data. Linear data maps the luma range in equal intervals from black to white. Logarithmic data allows for more subtlety in the lower luma ranges of an image. In Smoke, you can work with either logarithmic or linear data.
When you want to work with linear data, you can use an image conversion LUT on input to convert the logarithmic data to linear data. Since Smoke assumes that input data is linear, it behaves more predictably when you work with linear data than when you work with logarithmic data.
When you want to preserve the image data contained in logarithmic film scans and do not want to apply an image conversion LUT, you can work directly with logarithmic clips. Working with logarithmic clips prevents any data loss that could occur during the image conversion process. When you work with logarithmic clips, however, apply a LUT for display purposes. Display LUTs affect transient data only — no data conversion is committed to the clip.
