….If there is 1 lux of ambient light in the room (i.e. a small candle), the max perceivable contrast ratio is 500:1. A dimly lighted room with 30 lux of lighting would squash the maximum perceivable contrast ratio to 50:1 [2]. Unless you have a completely dark room covered in black velvet, you'll never be able to perceive the high on/off contrast ratios claimed by manufacturers — those numbers are meaningless otherwise….

That may be true if the otherwise black area of the TV reflected 100% of this ambient light source (which it obviously does not) thus the contrast does not deteriorate NEARLY as fast as the above quote would have you believe.

To put that in perspective, pretend you have a white surface / screen and are using a projector mounted behind you.

In a dark room, the contrast is going to be pretty average, like you would expect from a movie theater.

add ambient light (a candle or otherwise) and the contrast will suffer fast, just as mentioned above in the quote.

HOWEVER

Nearly every screen in existence will filter or absorb / re-direct that light, thus maintaining a good percentage of the original ratio.

Think about it… 30lux leaves you only a 50:1 ratio??? Typical room lighting could provide over 1000lux…. do you honestly think in that condition your only getting about 2:1 contrast ratio? common with a front projector maybe!

Here's at least one: Greg Rogers' review of JVC's DLA-RS1U in Widescreen Review, Issue 120, May 2007. I quote: "In the Normal lamp power mode, the RS1 produced 595 lumens, which is equivalent to 27.2 fL (foot-Lamberts) from my 1.3 gain screen, with an extraordinary 16,400:1 full-field (on-off) contrast ratio." JVC's spec is 15,000:1.

There have been other displays reviewed in WSR by Greg Rogers that meet or exceed their published CR's. Greg knows how to calibrate and measure displays properly and he's no stooge for the manufacturers.

Projection CRT has low ANSI CR, even with liquid coupling, because of this: The CRT phosphor emits light in an essentially lambertian pattern (i.e., diffusely). Some light from a high brightness feature will thus reflect from wherever the refractive index changes (glass-to-air-to-glass = a lot of reflection, glass-to-liquid-to-glass = less but not zero reflection) at a severe angle and illuminate some other part of the phosphor.

In the case of a micro-display, be it based on DLP, LCD or LCoS, light from the lamp is focused onto the panel, arriving from a far more limited cone of angles. The light which transmits through or is reflected off is thus much more efficiently captured by the lens – not as much of it is bouncing off at odd angles. There is still some, and there are still reflections within the lens itself because of all the glass-to-different-glass and air-to-glass interfaces, so it's not perfect. But it can be much, much better. (Note that anti-reflection coatings are typically used in both cases.)

Carlton said CRT/Plasma has the best contrast for displays, DLP for projection. Do you disagree?

I'm curious why CRT projection has poor ANSI contrast compared to DLP. If it is due to the lens system, how is the DPL lens system able to do better?

Second, CRT projectors are the "kings" of on/off contrast ratio, not ANSI. Their ANSI ratios are actually relatively poor, although rarely were the numbers ever published. A model with air-coupled lenses would be typically 50:1, a liquid-coupled model maybe as high as 200:1. In comparison, ANSI contrast for a well-designed DLP projector (for instance) is typically over 400:1. Yet there is no question that CRT projectors, even air-coupled ones, produce subjectively "punchy" pictures with good contrast.

Please take my comments as constructive criticism, based on over 20 years as a display engineer designing projectors (starting with those antiquated CRT models!).

Thanks for the site. Great info.

The link you posted in the comment is just a Pioneer press release. It's a good teaser, but so far just Pioneer's word. We'll need to wait for independent tests (like the ones you mentioned) to verify the claims.

Good article, Carlton.

Aside from projection, the 36" tube is my favorite for viewing.