240 Hz refresh, local dimming LED backlighting, and both THX and ISF certification are the highlights of LG’s premium LCD HDTV models.
While not the first LCD HDTVs to be THX certified, LG’s LH90 series sets are indeed the first to be available in the US and the first LED backlit LCD flat panels to attain that status. The THX certification is noteworthy, as many video aficionados consider LCD to be a decidedly second-rate player in terms of pure video performance compared to plasma, and obtaining THX certification is no small accomplishment—they are quite the fussy bunch. I’ve witnessed first-hand the extensive testing that the THX Video program entails at their San Rafael, CA facility, and I can safely say that there is no other third-party display evaluation program that goes as deep into video performance assessment as they do. The ISF certification adds additional video tuning functionality, with a suite of picture adjustments intended for use by professional calibrators, along with the ability to lock critical picture parameters afterwards to prevent inadvertent user mis-adjustment.
Along with the LED local dimming backlighting, LG equips the set with their 240 Hz refresh technology, which aims to smooth out judder from film sources while also sharpening up fast motion with fast action video content. As with some other LG models, the LH90 series features audio tweaking by famed audio designer Mr. Mark Levinson. While the set’s audio performance could never be called hi-fi (and is no substitute for an external audio system, which we always recommend), any attempt to improve on typically mediocre TV audio is to be commended.
Consider this HDTV if: you’d like a big screen LCD flat panel that is packed with the latest technologies, such as 240 Hz refresh and local dimming LED backlighting.
Look elsewhere if:you’re looking for a flat panel with a usefully wide viewing angle, as the LG’s off-axis contrast is noticeably faded compared to direct on-center viewing with moderate and dimly lit scenes. Consider instead one of LG’s fine-performing plasma sets, which have plasma’s typically very wide viewing angle.
Ratings (relative to comparably-priced LCD HDTVs):
LED local dimming backlighting is the principal differentiating feature here, compared to the more common fluorescent backlighting used in most other LCD flat panels. There are many hundreds of white LEDs spread behind the LCD panel (1,500 in the case of the 55” model), and the local dimming function allows variable brightness across the screen image, boosting brighter sections for more visual pop, and dimming darker sections for better deep blacks and dark grays.
The 55LH90 features both THX and ISF certification, a first for an LCD HDTV, with the set providing a built-in picture tuning system called Picture Wizard that includes a high resolution test image along with test patterns, which largely obviates the need for a DVD or Blu-ray test disc for basic picture adjustments. The THX Cinema mode provides a more natural-looking picture than the set’s quite bright and too vivid default Standard mode, but I found the THX mode’s default backlight setting to be too low for viewing in moderate or bright ambient light situations—dialing up the backlighting control a few steps easily corrected that problem without causing unnecessary glare.