Again, I have to say that this stuff mirrors the Home Theater front projector realm. ALL front projectors claim to be xxx lumens and xxx:1 contrast ratio... yet no one has EVER met these specs when testing them. I don't know how they get away with claiming these specs (just like some of the monitor specs), but it is just 'known' that every product spec is over-rated. Although there is one company who gives a more realistic spec (Infocus brand) and they get lots of word-of-mouth advertising because of this. I think people like it when they are not intentionally being lied to.
Maybe some of the companies making these monitors will come around and give a more realistic spec (or show a "best" spec and a "real-world" spec.) Honesty goes a long way in the HT (home theater) forums.
I don't know much about projectors, so I can't comment that much. I'll just have to take your word for it at this point. :) How they get away with it is probably the same as in the LCD world: A lack of standards.
In the LCD world however, what is listed is based upon the manufacturers measurements. In the datasheets, you can usually see how they have measured and what results they came to. Then they advertice the results from their own tests. Then companies like Dell/HP/Apple/Benq etc. puts together a screen where they use the specs from the LCD panel manufacturer.
While other manufacturers uses the results from their own tests, Samsung goes a bit further and decorate the numbers afterwards as shown above. Samsung tests the panel as 700:1/400 cdm2 and then they advertise it as 1000:1/500 cdm2, while other manufacturers would have used the initial test numbers 700:1/400 cdm2. There is a MAJOR difference here, don't you think? I feel they are trying to "screw" the consumers with their approach! :(
Lets make a little comparison to show my point even stronger. The panel of my very own screen, the HP f2304 (and also the HP L2335) is
LM230W02(pdf). From the Datasheet, the measurements are as following:
Typical contrast = 500:1, typical brightness = 250 cdm2,
Response times:
Typical/average BtW (Tr 8,5/Tf 7,5) = 16 ms (Maximum Tr and Tf is 15ms, which means in worst case scenario it will take 15 ms to change into a shade of black).
Typical/average GtG = 12 ms, Maximum GtG = 18 ms (which means in worst case scenario, it will take 18 ms to change colors).
As you might have noticed, the OPTIMAL haven't even been listed. Only typical and worst case/maximum.
They sell this panel with the typical measurements, 16 ms BtW, 12 ms GtG, 500:1 and 250 cdm2. If they would have used the Samsung model of sales, it would have been: 11 ms BtW, 7 ms GtG, 800:1 and 350 cdm2... ;)
So, how did Extremetech measure this panel? Granted that they had the old revision of the panel (there are even 2 manuals as mentioned before), they reviewed it as a HDTV, not a monitor and the clouding issues are not that common on the f2304 and the L2335. :P
Average contrast was measured as 466.2:1, ranging from 526:1 down to 421:1, due to a panel with obvious backlighting problems.
Extremetech review. Still, with an uneven backlighting, it performed as the Datasheet said it would. :)
Even if it hadn't, there would still be no mismatch as with Samsung between their own measurement and what they sell it as! :)
Do you see the differences? :)