Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!ncar!gatech!bloom-beacon!bloom-picayune.mit.edu!athena.mit.edu!spworley From: spworley@athena.mit.edu (Spaceman Spiff) Newsgroups: comp.graphics Subject: Re: Generating photographic grain imperfection in computer graphics? Message-ID: <1991Apr13.063208.22749@athena.mit.edu> Date: 13 Apr 91 06:32:08 GMT References: <5644@media-lab.MEDIA.MIT.EDU> <1991Apr12.183031.12462@dsd.es.com> Sender: news@athena.mit.edu (News system) Distribution: usa Organization: Massachusetts Institute of Technology Lines: 28 I would think that the color sensitivity of film would play a bigger role in the "film" look than the finite grain size. The film color gamut is typically much larger than any video display. A video display also has a nearly flat color sensitivity, wheras file does not have a uniform sensitivity to color. Delicate aquas are one example that comes to mind- they're definately less vibrant in film as opposed to pinks. Another thought about simulating the film "look" is a more detailed camera model. Certainly depth-of-field and motion blur are known and used, but how about subtler effects like change of focal character from the center of the focal plane to the edge? Or the film shutter- exactly how much time should be integrated over to characterize the light entering the camera? What about the beginning and end of the integration where the shutter is half-way covering the lens? I don't know how much effect these would have on a computer generated image, but if you're after a film-like look, these should probably be looked into. Scratches and dirt might also be interesting. Wow- try to model a hair or piece of lint that moves up the screen, and finally disappears. We've ALL seen this at the theatre! Good luck, Evan, on your quest. -Steve --------------------------------------------------------------------------- Steve Worley spworley@athena.mit.edu ---------------------------------------------------------------------------