LCD – For the Novice and the Expert

Where do manufacturers get their specs?

© VESA

We worked closely with VESA and NEC during our last few LCD reviews to assure our testing procedures were correct. Unfortunately, it seems as if not all manufacturers adhere to the same standards. LCD substrates are always produced to a certain specification, whether it be 250cd/m^2 or 16ms, etc. These specifications are straight from the OEM (LG.Philips, AUO). However, manufacturers usually retest the final product after assembling all of the components (including bezel and stand). Sometimes, if the manufacturer ends up with a more desirable figure, that figure goes into the final specification.

	Brightness (cd/m2)	Colors	Contrast Ratios
NEC 1760NX	260	16,200,000	450:1
ViewSonic VP171B	260	262,000	500:1
Hitachi CML174	260	16,700,000	400:1
BenQ FP767	260	16,000,000	500:1
Planar PX171M	260	16,700,000	400:1
AUOptronics (OEM)	260	262,000	450:1

As you can see, there are some clear irregularities, even though all of these monitors are produced from the same panel. Our general rule of thumb is to find the OEM for every monitor we review. Thus, when we looked at the Hitachi CML174, we compared our specification expectations with that of the AUO specifications. On the next page, you will see a short table of how each test is conducted for LCDs.