can anyone answer this already 
ako nahihirapan sa mga nagtatanong eh 
Matagal ko nang nakita ang question na yan, pero sa tingin ko hindi naman siya masisiyahan sa sagot ko, kaya iniiwasan ko sanang sagutin.
First of all, contrast ratio specs are not based on any agreed standard, so it really doesn't matter what those quoted specs are. What matters is how it looks like in real-world conditions, regardless of what the manufacturer specs say.
Limiting the issue to the correct manufacturer's spec, I say both specs are correct, except that the 3000:1 figure was Samsung's old measurement. Samsung just revised its standard of measurement and came up with a new figure of 5000:1, but it's still the same panel with the same actual contrast ratio. To update the spec and to improve sales, nilagyan ng sticker na may 5000:1 spec.
how will i know the true contrast ratio? tama ba term ko?
Manufacturer's contrast ratio specs are useless because there is no agreed standard of measurement.
To determine the "true" contrast ratio, there must first be an internationally accepted standard of measurement, then the contrast ratio must be measured by an independent body rather than by Samsung itself. Since that's an impossibility at this time, I wouldn't worry about the contrast ratio if I were you.
To appreciate how useless the manfacturer specs for contrast ratio are, it is essential to first understand the basics about contrast and grayscale.
How is contrast ratio measured?
The most common methods are the Full On/Off method and the ANSI Contrast ratio measurement.
Full On/Off Contrast measures the ratio of the light output of an all-white image (full on), vs. the light output of an all-black (full off) image. This is the measurement most favored by manufactures as it yields a larger number for the contrast ratio.
ANSI Contrast is measured with a pattern of 16 alternating black and white rectangles - also referred to as the 'checkerboard' test pattern. The average light output from the white rectangles is divided by the average light output of the black rectangles to determine the ANSI contrast ratio.
While ANSI contrast is more accurate, it still cannot tell you the whole story. That's because you do not watch black and white checkerboards on your screen in real life. In real world situations, grayscaling is even more important than a full-black and full-white comparison.
Another factor to consider is ambient light. Measurements taken in a room with ambient lighting will differ from those taken in a dark room.
To give you some idea about how wild those contrast ratio specs really are, consider this:
Did you know that a new movie in a movie house should have a contrast ratio of about 500:1? If so, then it is clear that a contrast ratio of 10,000:1 or more on an LCD or plasma TV is a fantastic and ludicrous claim.
To make all of this a little more concrete, let's enumerate some specimen contrast ratios. If you're reading these words, the contrast ratio of the page before you is about 80:1. If you're looking at them on your monitor, the ratio is closer to 50:1. If you go to the movies and watch a good, clean print, the ratio (given the right scene) might be 500:1. http://www.da-lite.com/education/angles_of_view.php?action=details&issueid=56The audio industry used to do this with their PMPO specs. This time, it's the video industry that loves to throw specs around.
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References:
The Contrast Ratio Gamehttp://www.practical-home-theater-guide.com/contrast-ratio.htmlLCD Specs: Useless?
Tested contrast ratios rarely conform to vendors' specs. http://pcworld.about.com/magazine/2106p024id110483.htm 
