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How does one measure 50,000 to 1 contrast? 1 Million?

 
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WanMan



Joined: 19 Mar 2006
Posts: 10270


Posted: Fri Jan 11, 2008 12:44 pm    Post subject: How does one measure 50,000 to 1 contrast? 1 Million?

Seriously, what kind of equipment and environment does one need to be employing to measure subjects with this kind of contrast ratio?

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garyfritz



Joined: 08 Apr 2006
Posts: 12088
Location: Fort Collins, CO

Posted: Fri Jan 11, 2008 3:13 pm    Post subject:

darinp2 on the A site used to do measurements like that. I think he used a 2-step approach, if I remember right: full-bright to half-bright, and half-bright to full-off, or something like that...

(dig dig) Looks like he measures the "half-bright to full-off" closer to the projector so he has higher light levels & thus stays within the reliable range of his measuring instrument. Here's an article he wrote that briefly describes his multi-step approach:
http://www.hometheaterhifi.com/volume_13_2/feature-article-contrast-ratio-5-2006-part-5.html

See also http://www.avsforum.com/avs-vb/showpost.php?p=9497236&postcount=50
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WanMan



Joined: 19 Mar 2006
Posts: 10270


Posted: Fri Jan 11, 2008 4:22 pm    Post subject:

Curious about something. If one treats the environment without any deliberately introduced light source as the lowest value then I think this is going to be mostly impossible for 99.999,999% of the individuals on the planet. Even then one needs to rule out non-visible wavelengths potentially contaminating the sensor.

Also, at someone's claim of 1 million to 1 (ludicrous, not plaid) would be seeking a fractional result of dang near 10K-20K to 1. And then when one reaches sufficient drinking to enter into this make-believe world, one can address the plaid (Infinite claims).

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deronmoped



Joined: 03 Nov 2006
Posts: 1154
Location: San Diego

Posted: Fri Jan 11, 2008 5:24 pm    Post subject:

You measure it like scientist do.

1) You create a crisis. You may not have to go that far, but the more people you can convince that it needs to be studied, the better.

2) You collect your grant money.

3) You build your facility in some state where their Senator needs to create jobs because he is up for re-election. This in turn guaranties you more money.

Heck, if people can get money to study the habits of some flea or lizard, lets get some so we study the effects of "CRT Projection Technology And How It Effects The Consumption Of Popcorn".

Deron.
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WanMan



Joined: 19 Mar 2006
Posts: 10270


Posted: Fri Jan 11, 2008 5:45 pm    Post subject:

My concern is really more with the notion that manufacturers can claim anything and not be held accountable for it.
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