<bold>Blackmagic Production Camera Raw Color Investigation by Spectral Analysis of Macbeth Color Charts </bold>

Abstract

Color is an important aspect of the camera quality. Above all in a Visual Effects Pipeline (VFX) it is necessary to maintain a linear relationship of the pixel color in the recorded image to the original light of the scene throughout every step in the production pipeline. This means that the plate recorded by the camera is not permitted to be subject of changes in any way (,,do no harm to the plate"). Unfortunately most of the camera vendors are applying certain functions during the input step to the recorded RAW material, mostly to meet the needs of the display devices at the end of the pipeline. But they also are adding functions to establish a certain look, the camera company is associated with.Maintaining a linear relationship to the light of the scene enables compositing artists and editors to combine imagery of varying sources (mostly cameras of different vendors). If for example an action scene is filmed using an ARRI film camera to capture the performance of the principal actors, additional imagery is derived using action cameras like the GoproHero. Also it is often desirable to have some less expensive camera at hand which can be moved around easily to take textures and imagery for example to create clean plates. A critical aspect in the production workflow is that all the imagery from the different sources can be combined easily in editing and compositing without additional color correction.The goal of this paper is to calculate the position of the patches of the GretagMacbeth color checker chart [1] (now X-Rite color chart) using an image recorded by the Blackmagic Production Camera and compare it to reference data sets based on those provided by the manufacturer and measured spectral data under the same lighting conditions. As a result a tendency could be obtained if the camera can be used inside the AMPAS ACES workflow.