6 Replies Latest reply on Nov 13, 2008 12:50 AM by Jonas Hummelstrand

    LED SCREEN EFFECT

    Level 1
      i'm looking to make an led "touch" screen. meaning i want to make a video where a hand can come out and write on the screen, they can push and move icons and objects onto the screen and off the screen. the idea is building off of ups' whiteboard campaign (http://whiteboard.ups.com/). so basically a screen that someone can interact with and im looking to make it look more like an led billboard, more computerized (if that's even a word). and if that's not something you guys have an idea for then maybe this one. i could use a computer screen as the idea so how would i recreate the look of when you press in on an lcd monitor, how you get the colors prisming out so i can use that as an effect to tie in the hand and the monitor so people realize what they're looking at. if you have an lcd monitor without the glass on it, just press in on it (softly so you dont bust your screen and then blame me for it) im sure you've seen it before.
        • 1. Re: LED SCREEN EFFECT
          Mylenium Most Valuable Participant
          This kind of stuff is usually done on blank monitors/ dummys with a green screen popped onto them. You draw the outlines with a thin white pencil/ chalk, so the actor has some guidance and you can later easily remove it while keying (in practice, it should not be visible at all in-camera), and add red tracking markers in the corners. Then you post-replace that with the actual graphics.

          Mylenium
          • 2. Re: LED SCREEN EFFECT
            Check out the colorama effect for the prism.. I haven't tried, but that might work...
            • 3. Re: LED SCREEN EFFECT
              bogiesan-gyyClL Level 3
              Wave World will be your primary effect to create these "poinks" on the screen surface. You will take the poink movie and move it to Colorama.

              bogiesan
              • 4. Re: LED SCREEN EFFECT
                Level 1
                Mylenium that's what i was thinking that i would use an lcd monitor and leave it off and get a green screen piece to fit the monitors screen so i can put anything i please on it afterward, where you lost me was with the white pencil thing. Make an outline of what with a thin white pencil? and as far as the red tracking markers go, what would i use them for since the camera would be on a tripod and have a steady shot i would need to motion track anything except the hand and the images, which the graphics will be done in post obviously so i figured i could sync them and motion track them to something else. on a side note, using RED markers is a good idea when it comes to keying? i figured since we have so much red in our skin that would make it a bad thing as far as keying things, what would be good colors for me to use to mock up where the graphics would be, i need more then one color as the graphics will 'maximize' and 'minimize'. thanks for all your help sorry if im asking too much. i really need this for a work project that's due soon and i'm brainstorming the most convenient way to do it.
                • 5. Re: LED SCREEN EFFECT
                  Mylenium Most Valuable Participant
                  With the white pencil you simply draw a few reference lines on e.g. your green cardboard that covers the screen. White artsit's pencils are very subtle and thus, due to the limited optical resolution of most video cameras (even in HD), enough of the green will "bleed" into the white to make it invisible. You can of course use other colors as well (light green, yellow, grays), as long as the contrast is low enough so you can "light it away". As for the red markers - that is not uncommon, regardless how the interaction may be otherwise. As with all greenscreen/ bluescreen stuff, it is down to what colors you use. Under normal light this should look more like a brownish, dark red and only show up under proper studio lighting. If so, you would have enough contrast with human skin, as this is a mix of colors and would also allow to extract luma information. Of course, depending on the situation other colors may apply, so e.g. a lime green or dull yellow would also work. Some people also use luma markers (silver tape, bicycle reflectors) or LEDs. To make a long story short: as long as you can easily remove it without ruining your key, it's perfectly legal...

                  Mylenium
                  • 6. Re: LED SCREEN EFFECT
                    Jonas Hummelstrand Level 2
                    Instead of covering the monitor with a keyable color, I'd recommend turning it on and displaying a solid color on it. That way you can track the corners (keying a screen won't do you much good since you also need to compensate for the perspective.)
                    Think of it like putting the "new" content on top of the screen rather than underneath it.

                    At the same time you'll also get indirect light on surrounding objects and people in the scene, plus the oh-so-important light on the screen's edges.

                    - Jonas Hummelstrand
                    http://generalspecialist.com/