A cutout shape is made for the “A” object that is to be extracted … basically a black matte with a window in it. Optical compositing is a four step process.ġ. Let’s say we want to put object “A” into background “B”. Surprisingly the basic principles of combining images onto photographic film, “optical compositing”, are very similar to digital compositing. The most successful colour turned out to be blue so that became the most popular background for shots to be matted. The pioneers worked out that film chemistry provided them with some emulsion layers that could be chemically isolated by colour, so if they shot a subject against a specific coloured background they could generate their matte shapes almost automatically. More ingenious photographic and optical minds got to work on how to do this kind of automatically using photochemical processes. Very manual techniques such as hand painting opaque liquid around objects directly onto film (the precursor to digital rotoscoping) were employed but were insanely laborious and nigh-impossible to execute with any realism. In it’s earliest form, it involved photographic processes such as simple multiple exposures onto the same piece of film. Visual Effects most core technique is compositing – since the dawn of film making itself, we have wanted and needed to extract parts of one scene and place them convincingly in another. This weeks fxpodcast, which accompanies the article, covers the Primatte keying plugin with Scott Gross of IMAGICA Corporation of America. In our continuing ‘Art of …’ series we turn to one of the central issues for compositors – keying.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |