Contrast ratios in projectors !!!

Discussion in 'Displays' started by Burki, Jul 4, 2005.

  1. Burki

    Burki Agent

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    Hi ppl,

    I am working in canon (in europe) and i am going to make a new campaign for its projectors. I didnt know anything about projectors but in 1 or 2 days, i learned alot of things and still learning.

    My problem is now contrast. As i know contrast is the ratio between the brightest and darkest point of the image. I want to know why contrast is so important for? Most models of different brands keep their contrast ratio around 2000:1 and this min 1000:1 but canon is starting from 300:1 and max is 1000:1. I want to know the reason of this if anyone knows.
     
  2. Michael TLV

    Michael TLV THX Video Instructor/Calibrator

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    Greetings

    It depends on the technology and the way they measure the contrast ratio. Different companies measure them differently. Some come up with figures based on absolutely ludicrous testing methods to maximize that number.

    The most accepted way for measuring contrast ratio is the ansi method of 16 boxes ... (8 white and 8 black)

    The silly way for getting those high CR numbers is to max out the contrast for the bright reading on a 100% white pattern and take the dark reading on a dead input with no signal coming in. (slightly better than the TV being turned off). The Max contrast white pattern is also a very small box ... which could be 2 to 5% of the entire screen surface.

    You get a high number, but it is totally unusuable as no real image has that type of CR.

    Real CR for usuable images is more in the range of 6-10% of the max. contrast ratio that they like to use.

    A 3000:1 plasma CR is actually around 200:1
    A 1500:1 RP DLP CR is actually about 110:1
    A 800:1 LCD RP CR is actually about 85:1
    A conventional tube set has a CR of about 200:1

    If Canon measures their CR with a larger white box ... the CR will be lower. Because manufacturers play these games, it is perfectly possible for a 300:1 CR set to have a better real CR than one boasting 4000:1 CR.



    Regards
     
  3. Burki

    Burki Agent

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    thx man. but why when we look to best projectors for dýfferent purposes at top 5 lýsts, we never see any canon product. As i know canon is always usýng hýgh qualýty materýal ýn their products and its products have hýgh prices. I dont think because of this they dont put this brand to top 5 lists. When we look to canons products, it has really good features.

    Why do you think it is like this?
     
  4. Michael TLV

    Michael TLV THX Video Instructor/Calibrator

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    Greetings

    Canon has not been a player in the TV world until very recently. It is also a good bet that they out source the product to somewhere else. They could be rebadged infocus ... benq ... etc.

    There are many many projector companies out there that have been doing this a lot longer than Canon.

    Regards
     

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