On Thu, April 30, 2009 23:50, herschel wrote: > One of the exercises I give students is to shoot something moving on 3 > successive shots. Then take the red channel from the first, the green > channel from the 2nd and paste them into the third (Blue) Thus the > Photoshop image has one colour channel from each image. > > You get the same result as using 3 filters and mutiple exposure. The > moving stuff (Clouds and water are popular) become "Rainbow" because the > primary colours are out of register. The stationery stuff is not affected. They used roughly this, on movie film, as a special effect in the original Star Trek. They made separations, and then printed them something like 3 frames out of register, so that things that stayed put looked fine, but things that moved had rainbow fringes. -- David Dyer-Bennet, dd-b@xxxxxxxx; http://dd-b.net/ Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/ Photos: http://dd-b.net/photography/gallery/ Dragaera: http://dragaera.info
