Designing and Specifying Display Systems

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Designing and Specifying Display Systems

  1. 1. 3/28/2013 1 Designing and Specifying Display Systems Copyright 2012 by InfoComm International® Visual Principles Objectives • This seminar covers five key points: – Determining an acceptable contrast ratio – Determining acceptable ambient light level on projection screen – Establishing actual projector brightness – Selecting projector and lens – Balancing task lighting
  2. 2. 3/28/2013 2 Copyright 2012 by InfoComm International® System Contrast Ratio • The light that is perceived at our eyes • Includes – Projector – Screen material – Ambient light – Viewing task Copyright 2012 by InfoComm International® Candle Power
  3. 3. 3/28/2013 3 Copyright 2012 by InfoComm International® Illuminance And Luminance • Illuminance • Light that is falling on a surface • Ex: light falling on a table • Luminance • Light coming from or transmitted through a surface • Ex: light entering a camera Copyright 2012 by InfoComm International® ANSI Lumen Calculation • Meter aimed at lens • Meter readings in “lux” • Average of 9 zones • Screen dimensions in meters • Avg. lux * meters ² of screen = ANSI lumens
  4. 4. 3/28/2013 4 Copyright 2012 by InfoComm International® Copyright 2012 by InfoComm International® System Black • Display systems create light, they do not create dark. • The screen’s ability to reproduce black is limited to the darkness of the screen when it is turned off • System black is defined by three parameters: – The material of the display screen – The ambient light level – The light from the display with a solid black image input.
  5. 5. 3/28/2013 5 Copyright 2012 by InfoComm International® • System Black Copyright 2012 by InfoComm International® Contrast Ratio • Measures the brightness compared with the ability to represent black simultaneously • Measured by average readings of 8 black and white zones each • High contrast images: – appear crisper – appear to have more depth. – easier to read text
  6. 6. 3/28/2013 6 Copyright 2012 by InfoComm International® System Contrast Ratio • The light that our eyes receive • Includes the entire light path – Projector – Screen – Ambient light Copyright 2012 by InfoComm International®
  7. 7. 3/28/2013 7 Copyright 2012 by InfoComm International® ANSI/INFOCOMM 3M-2011 • Projected Image System Contrast Ratio • 5 viewing positions • 4 viewing tasks Copyright 2012 by InfoComm International® Five Viewing Positions Closest LeftClosest Left Closest RightClosest Right CenterCenter Farthest LeftFarthest Left Farthest RightFarthest Right
  8. 8. 3/28/2013 8 Copyright 2012 by InfoComm International® Four Viewing Tasks • Passive Viewing minimum 7:1 • Basic Decision Making minimum 15:1 • Analytical Decision Making minimum 50:1 • Full Motion Video minimum 80:1 Copyright 2012 by InfoComm International® Conformance • CONFORMS: All five measurement (viewing) locations meet or exceed • PARTIALLY CONFORMS: One but no more than four measurement (viewing) locations falls below by less than 10% • FAILS TO CONFORM: The contrast ratio at any one of the measured locations falls below 10%
  9. 9. 3/28/2013 9 Copyright 2012 by InfoComm International® Calibrating With The Grey Scale Pattern Copyright 2012 by InfoComm International® 18
  10. 10. 3/28/2013 10 Copyright 2012 by InfoComm International® Calculate Projector Brightness Pbrightness = ((ambient light * 15 * screen area) / screen gain) / (1 – 0.XX derating) = ((55 lux ambient light reading * 15 * 92 in x 57.5 in screen) / 1 Gain) / (1-25% derating) Convert sq feet to meters for lumens result ( * 0.0929) = 3743.4 lumens Round up lumens to next commercially available projector Copyright 2012 by InfoComm International® What difference can a lens make? Lens aperture and f-stops Lens focal length = f-stop Lens diameter These represent full f-stops (1/2 or 2x light): 1.0 1.4 2.0 2.8 4 5.6 8 11 16 22 Brighter
  11. 11. 3/28/2013 11 Copyright 2012 by InfoComm International® Task Light Levels • ±3x range between display brightness and task lighting levels Copyright 2012 by InfoComm International® • This seminar covered five key points: – Determining an acceptable contrast ratio – Determining acceptable ambient light level on projection screen – Establishing actual projector brightness – Selecting projector and lens – Balancing task lighting
  12. 12. 3/28/2013 12 Copyright 2012 by InfoComm International®

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