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Contrast vs. Grayscale

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Building on the Focus vs. Grayscale tests, here's an additional tip from video specialist Michael TLV.

"On a similar vein, here is break out of some more empirical tests performed to see how contrast affects the TV's grayscale...

Bear in mind what the following represents. It is meant to give you an idea of what happens to the grayscale. Ultimately, your mileage may vary.

A preamble to what you are about to see. Contrast in my set has been adjusted to top out at 62 / 100 from where it used to be. That means at 63, my contrast rolls over to zero again and starts to ramp up to 38 by the time it reaches the 100 reading.

0 = 0 /100
62 = 62/100
63 = 0 /100
100= 38/100

The test is done using the 100 IRE window starting at a contrast setting of 25/100. (My own typical / optimal contrast level) The Ft-Lam is 3.7 ... pretty low, huh? But good enough for my viewing conditions. Apparently the Ft-Lam reading off the Philips analyzer might not be accurate ... so take it with a grain of salt as an exact value. Apparently, it should be higher than what the reading says.

25 - D6460 - 3.70 fl
30 - D6630 - 4.38 fl
35 - D6940 - 5.44 fl
40 - D7220 - 6.46 fl
45 - D7270 - 7.60 fl
50 - D7270 - 8.85 fl
55 - D7180 - 8.88 fl
60 - D7260 - 8.85 fl

Next question is ... why does the colour temp level off at 7200 ish from 40 to 60/100? I don't know ... but I wonder if finding an optimal contrast point has anything to do with what is going on here? 

Well you get the idea of what is happening. Every 5 notches up the contrast scale seems to bump the colour temp by 200 degrees.

Conclusions ... Contrast does affect the colour temp.

More things to worry about when you are trying to maintain that carefully calibrated grayscale. 

Like a bull in a china shop ... tread carefully ...