LG 77EG9700 UHD OLED—An Extended Critical Look

Over the course of the past year, AV enthusiasts have witnessed the death of plasma and the birth of UHD/4K OLED. Like plasma, OLED displays are emissive—each pixel lights up on its own. Emissive displays typically achieve deeper blacks and higher contrast ratios than their LED-backlit LCD brethren.

The first generation of consumer-oriented OLED HDTVs consisted of two 55-inch 1080p models: the Samsung KN55S9C and LG 55EA9800. Those two TVs introduced the world to curved-screen flat-panel displays. For a brief moment in time, that curve was OLED’s calling card. Soon enough, curved LCDs appeared, and OLED lost its curved cachet. The shift meant OLED TVs had to compete on price and performance, instead of relying on the novelty of the ultra-thin curved screen.

During that first year, the price of a 55-inch 1080p OLED took a vertiginous plunge. The price of a 55EA9800, which debuted at $15,000, fell to a street price of $2000. It’s replacement—the LG 55EC9700—debuted at $3500. Any way you cut it, that’s a tremendous price drop in only one year. Meanwhile, Samsung decided to take a pass on a follow-up to its KN55S9C—the company decided to pursue the market for curved-screen LCDs instead.

Currently, LG is the only company offering OLED displays to consumers. Its flagship OLED is the 77-inch 77EG9700, a curved-screen 4K/UHD TV that sells for $25,000. You won’t find it on display at your local Best Buy, so when Robert Zohn of Value Electronics (an AV retailer located in Scarsdale, NY) offered me a chance to spend a day with the 77EG9700, I took it. Even better, that day stretched into three separate visits, which gave me a chance to really dig into this OLED.

The First Visit

For my first trip to Value Electronics, on February 19, I rode shotgun with AVS Forum member Joe Whip (jwhip). The goal of the trip was to take a brief critical look at the 77EG9700. During that visit, we sat with Robert in his darkened home-theater demo room and watched a combination of 2160p and 1080p content on an uncalibrated 77EG9700.

The first 15 minutes of The Dark Knight on Blu-ray served as a reference for both color and contrast—a reference I revisited numerous times in the process of writing this piece. It looked good, but there were clear issues with grayscale tonality—we could see hints of green and magenta in clouds, pavement, and other typically gray or neutral objects. We also spotted a lot of video noise in shadow areas.

During the demo, I told Robert I brought a calibration kit with me, including CalMan 5 Pro and a pair of high-performance meters—the CR100 colorimeter and CR-250 spectroradiometer from Colorimetry Research. I suggested it would be quick and easy to perform a 2-point grayscale adjustment to see what difference it made. Robert agreed to try a quick calibration.

It only took a few minutes to perform the 2-point adjustment, and the results were well worth the effort. When we re-watched the same footage from The Dark Knight, everything snapped into place—grays were gray and skin tones looked natural. Furthermore, post-calibration measurements confirmed that the overall delta E of both the gamut and grayscale measured below 3, the threshold where errors become noticeable.


A quick 2-point grayscale adjustment resulted in a delta E of 3 or less.

Despite the improvement from the quick calibration, we could not help but notice some additional issues with that particular panel. The most obvious was a vertical stripe near the center of the screen. It was about an inch wide with soft edges. The stripe was slightly brighter than the rest of the screen, and it was clearly visible when displaying a gray full field. With real content, it was hidden most of the time, but in some scenes it was clearly visible.

We also noticed that the TV was crushing blacks, but that effect was very minor. The exaggerated noise/grain was the most obvious and distracting artifact, and we had no idea what was causing it.

I suggested to Robert it would be interesting to perform a more in-depth calibration, including 20-point grayscale and CMS (color management system) adjustments. I wanted to see if it was possible to get more out of that TV.

Robert mentioned that professional calibrators Kevin Miller and David Mackenzie planned to work on the 77EG9700, and he invited me to join that session as an observer. The pro calibration would use a Lumagen Radiance 2143 videoprocessor ($4000) to take care of color processing because it supports a 4913-point 3D LUT (lookup table).

However, I wanted more hands-on time with the 77EG9700 before joining the calibrators for the Lumagen session. Robert said that was not a problem, so five days later I took another trip to Value Electronics.

The Second Visit

On February 24, I returned to Value Electronics. I spent four hours working on the LG using CalMan and the Colorimetry Research meters, carefully tweaking the LG’s 20-point grayscale and CMS controls.

Performing a thorough calibration on the 77EG9700 was a tedious process because menu items on the screen affected readings taken by the meter. In order to achieve the accuracy I sought, I had to exit the menu for every measurement. Unfortunately, the in-depth calibration was a complete waste of time; I did not achieve an appreciable improvement over the 2-point calibration. In fact, using the 20-point controls mostly made things worse.

The problem is that LG’s 20-point grayscale and CMS controls generate contouring artifacts. Contouring makes smooth gradients look banded, and it tends to exaggerate noise and film grain. Any small improvements in measured accuracy—CalMan produced some very pretty graphs—were negated by a visible (but unmeasurable) degradation in picture quality. I reset all the 20-point controls to zero and I switched my focus to the CMS, where I dialed-in the BT.709 gamut.


A full calibration using the LG’s 20-point grayscale and CMS adjustments produced a pretty chart.

When I finished my calibration, I ran a ColorChecker scan using CalMan 5 and the Colorimetry Research CR-100. Technically, the TV passed the test; the average delta E for the scan was less than 3, which is below the threshold of human perception. However, some of the ColorChecker patches spiked well above a delta E of 3. After a few iterations of CMS adjustment and 2-point grayscale tweaking, I was satisfied that the 77-inch OLED was as calibrated as it was going to get using its built-in tools.


When I ran CalMan 5 ColorChecker, some color patches spiked about a delta E or 3.

It became clear that a video processor like the Lumagen Radiance 2143 is desirable if you want to get the most out of the 77EG9700. A dedicated processor offers a lot finer control over calibration, albeit at a rather high price. And even with a $4000 investment in a Lumagen Radiance 2143, that device can’t accept a native 4K/UHD signal—it’s limited to 1080p input with UHD/4K upscaling.

A fully 4K-capable Radiance is in development, but I expect it to cost considerably more than the 2143. Combine that with the $25,000 cost of the 77EG9700 and you wind up with a 77-inch TV that costs as much as a compact luxury car.

Since there was nothing more I could do to improve the picture quality beyond what the 2-point grayscale adjustment offered, Robert and I switched to critiquing real content. We spend about an hour scrutinizing the opening scenes from The Dark Knight.

As we sat and watched from about eight feet away, I kept seeing a lot of film grain and/or noise. I also spotted a few cases where screen-uniformity issues were visible with real content—the vertical stripe was still there.

The Third Visit

I returned to Value Electronics on Saturday, March 7. When I arrived, Kevin Miller and David Mackenzie were hard at work calibrating TVs, including an LG 65EC9700 OLED. The 77EG9700 was in the showroom now, hanging on the wall next to a calibrated Samsung UN78HU9000. I must admit that I did not immediately recognize it as an OLED—in a bright room, it looked a lot like the LCDs.

We discussed the experience I had working on the 77-incher’s 20-point grayscale controls, and how I found it unusable. Kevin and David were not surprised that LG’s controls did more harm than good—apparently, that issue is not exclusive to the 77EG9700.

David played a scene from Argo and paused it on a close-up of a face. I was surprised to see pronounced, unnatural mottling in what should have been smooth skin. The calibrated Samsung 78HU9000 hanging right next to the 77EG9700 showed no sign of that artifact. With the image still on the screen, David rolled back the LG’s CMS adjustments. As he set each level to zero, the overall picture quality improved before our eyes—visible proof that the CMS system in the LG did more harm than good.


Using the CMS controls on the LG caused the mottling you see on the left. Resetting the CMS controls cleared things up, as seen on the right.

At that point, the need for an external video processor was self-evident. The LG 77EG9700’s built-in calibration controls are only useful for creating pretty graphs in CalMan, not for creating pretty pictures on-screen. None of this was a big surprise to the pros, who have worked with other LGs that exhibit similar issues. The answer to the problem was to use the Lumagen Radiance.

Kevin Miller performed the 77EG9700 calibration using a custom workflow (that he designed) in CalMan and a Klein K10-A colorimeter. He achieved much better results with the Radiance; image quality was clearly superior using a 3D LUT to correct color and grayscale. We played the same scenes from The Dark Knight, and the result looked great—not only were colors more accurate, they were also richer. When we dimmed the lights, the LG’s exceptional contrast made the LCDs in the room look pathetic in comparison.


Kevin Miller performing the calibration.


CalMan 5 cranking out a 3D LUT for the Lumagen Radiance 2143 and LG 77EG9700 combo

As good as the 77EG9700 looked, several of its flaws remained. The excess noise did not go away, and the vertical stripe was still there. The TV also appeared to crush blacks, if only slightly. As an experiment, we bumped up the brightness control a few notches until we saw the first hint of illumination in the letterbox bars. The crushed blacks went away, and the result was a very compelling image—color accuracy and shadow detail were superb. I wish I’d had a chance to measure the black levels after we tweaked the brightness control, but by then it had gotten very late and we were all ready to go home.

Ultimately, there is a lot to like about the LG 77EG9700, but it is not perfect. The vertical stripe we spotted could very well be a one-off defect of that particular panel, but the issues with LG’s calibration controls were not—that is clearly a design flaw.

The exaggerated noise is a real issue—I watched the same scenes from The Dark Knight on a Samsung F8500 plasma, aPanasonic AX900 UHD LCD, and numerous other LCDs in the Value Electronics showroom. The excessive noise appeared only on the OLED—it’s not in the content. I also noticed that off-axis viewing introduced a mild color shift in the image. It’s not a big shift, but there is a viewing cone outside of which color accuracy diminishes. Even so, it’s better than the vast majority of LCDs in that regard. Only the very best IPS LCD panels exhibit better off-axis color accuracy.

I applaud Robert Zohn for inviting such scrutiny of a TV that he sells. At the end of the day, when we shut off all the lights and compared the calibrated and tweaked 77EG9700 to all the LED-lit LCD TVs in the showroom, it looked better—a lot better. From a normal viewing distance, its positive attributes trumped any of the flaws I’ve mentioned. The seductive combination of OLED’s high contrast and color accuracy are sure to inspire a few well-heeled buyers to invest in this bleeding-edge TV.

Crucially, if the vertical-band uniformity issue is a one-off defect, what remains is the noise issue. According to David MacKenzie, there is a strong possibility that the noise results from the way the 77EG9700 processes color, as opposed to an issue with the panel itself. Ideally, I’d like a few more days to experiment with a 77EG9700—I’d love to find a solution to the noise problem—but my time was up.

The irony of high-end gear is that the closer you get to perfection, the easier it is to spot any flaws. Even so, if you compare the latest generation of OLEDs to what was available just a year ago, you can clearly see that LG has made tremendous progress. At the 2014 Value Electronics Flat-Panel Shootout, LG’s 55EC9300 tied for first with Samsung’s PN64F8500 plasma. But the 55EC9700 had many more image quality-related issues than the 77EG9700. If Robert hosts another shootout this year, I suspect the latest OLEDs will be unbeatable.

Calibration Reports

Click here for Kevin Miller’s calibration report using the LG 77EG9700’s built-in color processing:

Click here for Kevin Miller’s calibration report with the Lumagen Radiance 2146 taking care of video processing

TOOLS

SpectraCal CalMan 5 Professional Calibration Software
DVDO AVLab TPG 4K Pattern Generator
Colorimetry Research CR-100 Colorimeter
Colorimetry Research CR-250 Spectroradiometer