Densité Optique I (Optical Density I) mark a chromatic decomposition of the image. The choice to show a scrolling film movie as an extreme slow motion, frame by frame voluntarily directs the gaze on the work of the image. This aesthetic can remember those photographs retouched by painting. However, this type of image is obtained by a chemical decomposition of the film emulsion. Indeed, it is composed of three colored layers deposited on a transparent plastic substrate. Light passing through these layers is tinged with the colors and optical density, recreates the images and colors of the frames. Certain mixtures of chemistries acids attack these layers in the decolorizer, diluting in different aspects.