reviews

Real World Contrast Ratio "RWCR"

Because there are so many claims made about contrast ratio and the test is often performed using criteria that in no way relate to the real world we thought we'd find out once and for all what projectors can really do by devising a "Real World" test.

The CR test known as "full on/off" is open to abuse, you're now seeing numbers approaching 100,000:1 yet the ANSI CR may be as low as 8,000:1. It's generally performed in a mode you would not use for cinema displaying nothing more than a white screen then a black screen which has little to do with watching a movie. Yes it's a guide to the projectors performance and all things being equal the more the better but all things are not equal in real life.

Looking at the 7 gray rectangles in the image below the 4 on the right are much darker so that projector must be better at producing blacks than the model that produced the 3 rectangles on the right?

Actually they are the same! What makes the 4 on the left look darker is the way our eyes perceive brightness and contract, the key word is perception and it's greatly effected by the surroundings. That's real world.

For example you turn down all settings to minimum then measure a black screen, next everything up full and measure a totally white screen, this has little to do with watching movies.

The real test for a projector is to measure minimum black and maximum white AT THE SAME TIME.

This way you can't cheat by turning the contrast way down as you'll turn down the white reading as well as the black.

Our "Real World" Contrast Ratio is the ratio between the black and white measurement on our in-hose test image.

You'll note it's on a black background with a person plus several measuring points. Two are black one is 100% white.

We test all presets and list the total average CR plus the best setting.

We use a 100 inch screen and have the projector 3M back in a dark room.

We're adding to this review so keep checking back.

Data examples:

* Real CR using our "Real World" CR test [RWCR]
* After 92 hours use = 12% loss.

Our tests are "Apples for Apples" so even if you disagree with the numeric values the comparative values stand.

Projectors like the Sanyo PLV Z3000 and Epson EH TW4000 have far darker blacks, in fact we needed to get a lot closer to the projector to even measure the light output when showing an all off screen.

Note how the ANSI lumens are higher than stated to allow for degradation over time, having said that the lower the lumens the less they seem to degrade.

Color Luminance

3LCD supporting companies have introduced the concept of an additional criterion for assessing projector quality based on Color Luminance.

This new way to measure a projector's performance in color indicates the brightness of the primary colors projected onto the screen.

With Color Luminance, projector consumers would have more information available about the quality of their color images when determining their choice of projector.

To measure Color Luminance, the lumens of three primary colors (red, green and blue) are measured in nine fields, three of each color. The lumen measurements are added up and then averaged to determine the Color Luminance rating.

"3-LCD models will score much higher than DLP (single chip) projectors because the colours are projected in parallel R+G+B which makes them stronger than sequential projection i.e. R then B then G as per DLP -- HCC"

This new measurement supplements information already available to users about projector performance, including specifications that measure in black and white, such as contrast and ANSI Brightness.

The same color image projected from two projectors can appear different, even if the ANSI lumen ratings are the same, because the ANSI ratings are based on a white image. Since projection is typically in color, this new color measurement information is helpful to end-users.

Along with the most recent 3LCD applications, details of Color Luminance will be presented in the 3LCD booth at InfoComm06, Orange County Convention Center, Orlando, Fla., U.S. from June 7 to 9. Additionally, information about Color Luminance will be available at the booths of Epson, Sony, Sanyo and Hitachi.

Thanks to ausmedia.com.au for some of the information from the page http://www.ausmedia.com.au/projector%20contrast%20ratio.htm

About 3LCD
3LCD is the world's leading microdisplay technology, projecting images that are bright, natural and easy-on-the-eyes. The 3-chip optical system delivers rich, vivid, intense color, and has already been successfully installed in millions of 3LCD projection systems worldwide. [more]

HCC