Calibrating a non CRT display

Discussion in 'Displays' started by Jon Krangel, Jul 17, 2003.

  1. Jon Krangel

    Jon Krangel Stunt Coordinator

    Joined:
    Dec 14, 2001
    Messages:
    58
    Likes Received:
    0
    Trophy Points:
    0
    My friend and I both own products using the VPL-VW11HT projection engine (he a projector, me a Grand Wega) and we cannot figure out how to properly calibrate these devices. I have AVIA, however, the instructional videos only seem to mention CRTs. What should we do?
     
  2. Michael TLV

    Michael TLV THX Video Instructor/Calibrator

    Joined:
    Mar 16, 2000
    Messages:
    2,909
    Likes Received:
    1
    Trophy Points:
    0
    Location:
    Calgary, Alberta
    Real Name:
    Michael Chen
    Greetings

    Same rules apply for LCD ... except in the case of contrast.

    Go to a grayscale step pattern ... with black to white and all the other steps in between.

    Pump up contrast until you see the top two or three white boxes become one ... this is called white crush ... so back off until all the boxes are distinct ...

    That's it. All other methods are the same.

    regards
     
  3. Guy Kuo

    Guy Kuo Supporting Actor

    Joined:
    Mar 6, 1999
    Messages:
    581
    Likes Received:
    0
    Trophy Points:
    0
    AVIA was designed to work with digital displays, but the step by step narrative was tailored for CRT displays. As a result, many never realize that their AVIA DVD is already digital display ready. The test features for digital display setup are in the patterns, but not prominently described.

    Setting black level, saturation, hue and sharpness can be done just as with CRT displays, but contrast should be done differently. There is no bending nor blooming effect to look for on a digital display. Also, unlike with a CRT or CRT RPTV running white level up too high won't injure a digital projector.

    In the case of digital projection increase contrast until you see the point at which the moving white bars begin to vanish into the white background. That indicates that contrast is high enough that clipping happening. You don't want clipping so back down the contrast until both moving white bars can once more be seen. This is the highest contrast setting which does not clip hilight details. You may be able to leave the display at this point, but a large number of digital display suffer a grayscale shift when contrast is set too high. Look at the log steps in the middle of the pattern. Are they all the same color and differing only in intensity? If so, the current setting is fine. If you see that there is a color difference, particularly between the brightest and 2nd brightest steps, then back down contrast to where the shade of white is the same through the steps.

    Once this is done, go back and retouch brightness.
     
  4. Guy Kuo

    Guy Kuo Supporting Actor

    Joined:
    Mar 6, 1999
    Messages:
    581
    Likes Received:
    0
    Trophy Points:
    0
    Michael types faster than I do.
     
  5. Jon Krangel

    Jon Krangel Stunt Coordinator

    Joined:
    Dec 14, 2001
    Messages:
    58
    Likes Received:
    0
    Trophy Points:
    0
    Sounds good! Thanks.
     

Share This Page