Panasonic BT-LH2600W

The Future of LCD Monitoring in the Studio

Kevin Kilbride

March 1, 2007    Source: Studio Monthly

With an ample 26-inch viewing diagonal sporting a true 16:9 aspect ratio, Panasonic’s BT-LH2600W brings up the flagship position in the company’s professional LCD monitor line-up. Although not especially large by today’s flat-panel standards, the LH2600W is noticeably larger than its 17-inch LCD cousin in Panasonic’s pro range and provides a rectangle of nearly optimum size for viewing distances of two to three feet.

The incredibly high contrast of the LH2600W, coupled with its not-exactly-black shadow levels, amplify video defects in source material to colossal proportions. Any Gibbs noise, gradient banding, block aliasing or other artifacts in the signal will show up on this display with blatant misdemeanor. Video aberrations that once appeared subtle when displayed on the lower contrast of a CRT will be much brasher on this imaging engine. Conversely, if content looks good on the Panasonic panel you can rest assured it’ll look marvelous on a CRT— provided the CRT is not sitting next to the LH2600W.

The Ins and Outs

This display has inputs for Composite, Y/C, analog Component (both color-difference and RGBS) and two SDI feeds. All inputs except Y/C are terminated on BNC connectors. There’s even a separate vertical sync input so you could use the panel with RGBHV computer signals, although the lack of a DCC "plug-and-play" channel means you can’t auto-configure the graphics card; the panel’s input sync range is also rather narrow. Fortunately, it was easy to configure a GeForce card to generate the acceptable 1368 x 768 resolution at 60 Hz— two pixels wider than the native resolution of the panel itself, but necessary because modes on GeForce cards must be an even multiple of 8-pixels. Similar arrangements are possible on other common graphics cards.

Scaling Up and Down

You may notice, from the resolution quoted above, that 1080-line HD content must be down-converted to fit the LH2600W’s LCD panel, as is the case for most recent panels of this size and type. Panasonic has, however, added a feature that will let you evaluate SDI sources by switching to a windowed pixel-for-pixel view of the unscaled video; you can pan to any of the nine quadrants in the resulting virtual frame. You can select this function, along with many others, via an on-screen menu and optionally bind it to any of the five user-programmable buttons. Safe-area masks, gamma curves and even a built-in waveform monitor can be assigned to the panel buttons, as well. A separate set of dedicated buttons are for source selection.

The LH2600W may not be able to display 1080 HD without scaling, but at least the scaling it performs is virtually flawless. LCD switching speed also leaves absolutely nothing to be desired. Even on the most torturous high-contrast scenes— suffering from both telecine 3:2 pull-down and quick pans— I couldn’t make this panel cough up visible signs of lag. I didn’t notice any obvious deinterlacing or scaling artifacts, either. This is not to say that telecined video was visibly smooth— human flicker sensitivity increases with contrast, so the LH2600W occasionally rendered cinematic content with nearly punctuated kinematics.

Unsurprisingly, it was possible to tone down both spatial and temporal deficiencies in video by reducing the backlight drive strength, but this would be very difficult to advise. The image looked so much better, and was so much more revealing, when the panel was left at its default calibration that I really can’t imagine trying to subdue it just to make 24fps content look smoother. At any rate, computer video at 60 Hz rendered quite smoothly, as did 30fps broadcast-standard video, so the panel itself clearly had no issues with temporal artifacts.

Noise Evaluation

There was only one notable flaw that I discovered during my evaluation: a terrible whine made by the panel’s power supply. The noise was surprisingly loud, with principle harmonics well under 1 KHz (where they were especially irritating). The fact that the panel would sometimes telegraph this annoying sound in a bizarre staccato pattern led me to conclude, however, that the problem was not an intrinsic design flaw. It was unique to the unit I received, which had been shipped around the country to various places prior to my review.

At least the built-in fan was quiet. Not quite inaudible, but definitely more polite than the one in the 17-inch panel I reviewed last year and easy enough to live with. The fan is switchable, for silent operation (at least on units with non-defective power supplies), but the resulting drop in backlight intensity may require you to adjust the image. The panel exhibited strong relationships between backlight intensity and gamma, with one steep built-in transfer function restoring vibrance compellingly in the fan-off mode, though that wasn’t the intent. Naturally, typical users will want to leave the fan on and calibrate the unit at maximum backlight drive. It will yield images with the most linear contrast this way, given the fixed black-level of the panel.

Overall, the BT-LH2600W performed admirably, as you might expect from an LCD panel in its price range. Solidly fabricated, with gorgeous reproduction characteristics, the 26-inch LCD is a display device that can very nearly put the old CRT program monitor to bed forever.