LG 52LBX LCD TV Setup & Tests
Without 1:1 mode engaged, the 52LBX crops the picture on all four sides by at least 30 pixels or roughly 3 percent. That's among the most aggressive overscan amounts I've seen. The impact on 1080i signals was obvious in a luma-burst test pattern, which showed strong banding at the highest 37.1MHz frequency via HDMI. The same frequency was completely rolled off when this pattern was viewed via component video, so I definitely recommend using an HDMI hookup with this set.
Relabeling the HDMI input to "PC" turns on 1:1 mode and disengages overscanning with a 1080p signal, displaying all 1920x1080 pixels and removing the banding from the high-frequency luma burst and the 1-on/1-off pixel-phase pattern from Digital Video Essentials. However, a 1080i signal still appears to be overscanned slightly, with at least one pixel cropped from the sides and bottom and two cropped from the top. Also, the 1-on/1-off pixel-phase test pattern shows obvious banding, a clear sign of overscanning.
Turning to the white- and black-level adjustments, I found that the whites were clipped if the contrast control was set above 80. Satisfactory dark-room light output and deeper black levels can be achieved with the backlight control turned all the way down, but I ended up setting it to 27 to provide more punch and allow more comfortable viewing with some ambient light in the room.
Happily, relabeling the HDMI input to "PC" did not clip below-black and above-white as I thought it might, since the dynamic range of most PC signals is 0-255 rather than 16-235. However, engaging the PC mode did change the black level, requiring me to increase the brightness setting for that mode.
UAV's normal practice when reviewing a TV is to first carefully adjust the basic picture settings (contrast, brightness, color, tint, sharpness, and backlight) using test patterns and the user-accessible picture controls, then calibrate the set's grayscale using instrumentation and the additional controls tucked safely away in the service menu. The basic picture settings can often be left alone or copied to the matching controls in the service menu.
This proved impossible here, however, because the optimal picture settings for the User mode differed wildly from those required when the service menu was engaged. Furthermore, I found that the white- and black-level controls in the service menu moved in non-linear steps, making precise adjustments difficult.
UAV editor Scott Wilkinson and I painstakingly calibrated the LG's Expert1 picture preset. (The Expert1 and 2 presets can only be adjusted from the service menu.) We were able to improve the set's slightly blue out-of-the-box grayscale, though it wasn't all that far off in the first place. In the final analysis, we needn't have bothered.
The LG's color primaries measured pretty close to accurate, except for green, which is extremely oversaturated. When all was said and done, I found that the calibrated Expert1 mode made the TV's over-hyped greens look even worse—a lot worse. After much flipping back and forth, I ended up leaving the TV in the User1 mode, uncalibrated grayscale and all. I can't recall ever running into a similar situation, but in this case, I don't recommend hiring a professional to calibrate this TV. Simply adjust the user picture controls according to the settings provided later in this review and be done with it.
On the HQV Benchmark DVD at 480i via component, detail looked good and jaggies were mild to moderate. The LG's XD Noise function proved quite effective, and it can be left engaged without sacrificing much detail. This is a good thing, since the LG's picture is a bit noisy overall compared to some other sets. Cinema Film mode (3:2 pulldown) worked well, but it's only available at 480i, not 1080i.
The noise test on the HQV Benchmark HD DVD at 1080i via HDMI looked a little worse than some. The video resolution-loss test showed banding in the high-frequency bursts, but no jaggies on the rotating bar. The film resolution-loss test showed significant shimmering in the high frequencies, indicating that the LG was not locking into 3:2 pulldown. There was considerable moiré visible in the bleachers and noticeable loss of resolution during the pan. The LG was similarly unable to lock into 3:2 pulldown on the Spears and Munsil test HD DVD.
Finally, the various motion tests on the FPD Benchmark Blu-ray test disc were cleaned up by TruMotion, though the moving monoscope pattern had lots of artifacts regardless of the setting (High, Low, and Off). Even so, I thought the High setting smoothed out motion the most without introducing too many artifacts in the other tests and real-world content.