Until recently, Panasonic enjoyed an enviable reputation for building some of the best TVs money could buy. The company’s plasma TVs frequently ranked at the top of reviewers’ lists. Unfortunately, nothing lasts forever, and plasma televisions are now a relic of the past.
Unlike some other Japanese TV makers, Panasonic has not stopped selling TVs in the US market, nor has it stopped improving its UHDTV offerings with LED-lit LCD models. At CES 2015, the company even showed an OLED prototype that actually went into production—it was recently released in Europe as the CX950. However, in the US, the company’s TV offerings are 100% LCD-based. When I first saw a CX850 prototype at CES 2015, I left with the impression that the company had finally produced a TV with a winning combination of full-array local-dimming (FALD) LED backlighting and a vertically aligned (VA) LCD panel.
At that time, Panasonic’s flagship LCD UHDTV was the TC-65AX900, which featured an in-plane switching (IPS) LCD panel. IPS panels have very wide viewing angles—similar to plasma—but their native contrast is quite low—typically around 1000:1. The AX900 compensated for this using FALD backlighting, which worked well, thanks to its 128-zone FALD array—the more zones the better. While the AX900 was a great TV by any standard, it was also very expensive and occasionally struggled to render deep blacks in complex scenes.
At CE Week 2015, the CX850 took part in the Value Electronics flat-panel shootout. I expected the CX850 to perform well in the shootout, which was all about how the candidate TVs handled 1080p content produced in the BT.709 standard that is used for mastering Blu-ray content as well as broadcast TV.
Unfortunately, the CX850 did not keep up with FALD LCDs from Samsung and Sony, at least when it came to contrast, shadow detail, black level, and viewing angles.
I was a bit baffled about why the CX850 could not muster performance that was in the same ballpark as the Sony XBR-75X940C and Samsung UN78JS9500, both of which feature VA panels and FALD backlights. What I saw—and voted on—directly contradicted the post-calibration measurements from the shootout, which indicated the TC-65CX850U had both the highest native contrast and the deepest blacks of the three. In the end, the CX850 came in last place at the shootout, and lagged behind the other competitors by a significant margin.
A few weeks after the CE Week event, I headed to Newark, NJ, to have a look at a CX850 in Panasonic’s R&D facilities. I wanted to improve my understanding of what I saw at the shootout. After adjusting some settings and taking a few measurements, I grew convinced that the calibration of the CX850 at the CE Week event featured sub-optimal settings. I requested a review sample of the CX850, and by mid-July I was working with one in my studio, in search of settings that would let the TV shine. This review is the result of that effort.
Panasonic’s CX850 is a flat, 120 Hz, FALD, VA, UHD/4K LED-LCD with support for HDR and WCG. Translation: flat-screen (as opposed to curved), 120 hertz refresh rate, full-array local dimming, vertically aligned, ultra-high definition/4K, light-emitting diode liquid-crystal display—with support for high dynamic range and wide color gamut.
As with other high-end Panasonic TVs, the CX850 offers a variety of tools to help tweak image quality for maximum performance. It supports automatic calibration, 10-point grayscale adjustment, and a tablet/smartphone app that’s designed to make calibration easier—for example, using the app eliminates the need for on-screen menus that can skew meter readings.
The CX850 sports nine different picture modes, including several that cater directly to videophiles. THX Cinema and THX Bright Room will appeal to owners who want an optimized out-of-the-box experience, while the Professional1 and Professional2 modes offer in-depth options for calibration. Other modes include Vivid, Standard, Home Theater, Cinema, and Custom.
Panasonic offers the CX850 in two sizes: 55″ and 65″. However, the 55″ version only has 12 FALD zones. The 65-incher provides 30-zone FALD and offers a wider color gamut than the 55″ model—it covers 98% of DCI/P3 (the standard used in commercial theaters), as opposed to 90% with the smaller model.
All three of the TV’s 18 Gbps HDMI 2.0 ports support HDCP 2.2 copy protection. Additional connectivity includes Wi-Fi, an Ethernet port, two USB 2.0 ports, one USB 3.0 port, Bluetooth, and an SD card reader. There’s one coaxial connection for antenna/cable, as well as one set each of component and composite analog-video inputs—both with 2-channel analog-audio inputs.
The TVs audio outputs include audio return channel (ARC) via one of the HDMI ports and an optical digital-audio connection.
Panasonic provides two remotes with the CX850 as well as a control app for smartphones and tablets. The infrared remote is quite decent; the buttons are large, clearly marked, and backlit. The channel and volume buttons are located in the middle and are very easy to find by touch alone. It also includes a 4-way cursor cluster for menu and app navigation—it’s a solid remote.
The Touch Pad Controller is a smaller remote that communicates with the TV via Bluetooth. It is sleeker than the IR unit, but it’s not necessarily any easier to use. The touchpad makes web surfing with the TV’s built-in browser a lot easier, but who uses a TV to browse the Internet? Regardless, if you prefer swiping to clicking then it’s the remote for you. A built-in microphone works with voice control and search.
The control app—called TV Remote 2—provides a highly intuitive interface for controlling the CX850. One of its most notable features is a touch-enabled graphical interface for making calibration adjustments. You can use it to adjust settings without calling up on-screen menus that can interfere with measurements.
The CX850 offers a revamped My Home Screen app interface based on the Firefox OS. I’m not a big fan of using the built-in apps of any TV; I prefer to use a Roku or stream from a PC. Nevertheless, the TV offers plenty of apps to choose from, and the built-in Wi-Fi worked smoothly when I streamed content from Netflix, YouTube, and Vudu.
The CX850 has plenty of apps available through its Firefox OS interface.
My primary goal in reviewing the CX850 was to find the best possible settings for viewing Blu-ray movies in a darkened room—that’s the usage scenario where LCDs tend to struggle the most. This meant performing a BT.709 calibration with FALD activated. Crucially, Panasonic’s CX850 dimming algorithm is far more effective when used at its maximum setting, but finding calibration settings that worked well in that mode proved tricky.
Check out this video clip to see the difference between the CX850’s FALD modes.
The out-of-box color of the TC-65CX850U was reasonably good, but not as accurate as the AX900 I reviewed previously. The main challenge with the CX850 was this: When FALD was set to maximum, the resulting gamma curve was extremely out of whack.
I calibrated the CX850 in Professional1 mode, which offers unrestricted access to all picture-related controls. I used a kit consisting of a Colorimetry Research CR-100 colorimeter and CR-250 spectrophotometer with CalMan 5 software to calibrate the CX850 to the BT.709 standard with a target peak luminance of 35 foot-lamberts and a gamma of 2.4.
Finding a settings recipe that works optimally for any given FALD implementation involves time-consuming trial and error. That is likely why the CX850 underperformed at the shootout—the TV had arrived the day before the event, which left too little time to figure out how to get the best performance out of an unfamiliar TV. Fortunately, after a few days of experimentation in my studio, I found an approach that yielded a good result.
When I first calibrated the CX850 with FALD enabled, I wound up with accurate color, but the TV continued to suffer from poor gamma. The biggest issue was black crush, which compromised shadow detail. The fix I found was a bit of a hack, but it worked: I set the TVs gamma to 2.2 and used the CX850’s “gamma detail adjustment” controls to achieve a nearly perfect 2.4 gamma curve.
The result of calibrating with FALD set to maximum was worth the effort. After I completed the calibration, the CX850 measured well in a CalMan ColorChecker sweep, which samples many colors at various luminance levels. I achieved an average delta-E of 1.6, with a maximum of 4.7. That’s a very good result, and similar to what I saw when I calibrated my reference Samsung PN64F8500 plasma (average delta-E 1.9, maximum 4.0).
The post-calibration performance of the CX850 was a clear improvement over the out-of-the-box settings. Furthermore, it offered the deep blacks I was looking for without compromising shadow detail. The image quality of the CX850 was consistent with what I expected to see, based on specs and measurements. Switching between the FALD settings confirmed what I already knew—only the maximum setting offered satisfyingly deep blacks in a dark room. This was most noticeable in the letterbox bars when viewing 2.35:1 content; the bars looked gray in any other mode.
I was excited to have found settings that worked well with the CX850, but I was a bit less thrilled when I compared its performance to another TV I was reviewing at the same time: Vizio’s M65-C1.
As part of this review, I set up my studio with three TVs—the CX850, the F8500, and the Vizio M—in an arc, so that I could view each of them directly on axis when I was seated six or seven feet away.
When viewing the three TVs simultaneously, I appreciated the accurate and rich color of the CX850—it was about as good as the F8500 reference plasma. However, I could not help noticing that the Vizio managed to produce an equally compelling image. While the CX850 had a slight edge in color accuracy, it was actually inferior to the Vizio when it came to motion resolution, perceived contrast, viewing angles, and screen uniformity.
In the following video clip, the TV on the left (the first TV) is the Vizio M65-C1. The Samsung F8500 is in the middle, and the CX850 is on the right. When I pan the camera and follow the scrolling image, it’s clear that the CX850 can’t match the Vizio’s motion resolution, much less the plasma. Moreover, if you watch the video carefully, you’ll see some very obvious uniformity issues in the CX850—what’s often called the “dirty screen effect.”
Another issue I found with the CX850 was that its image quality rapidly deteriorated when viewed from an angle, resulting in a diminished viewing experience. While I have yet to see an LCD-based TV that can match a plasma when it comes to viewing angles, the CX850 only looks exceptional when viewed directly head on.
I watched a variety of real content with the CX850, including movies that depend on deep blacks to render outer space such as Gravity, Interstellar, Guardians of the Galaxy, and Star Wars: A New Hope. These movies will test any display’s contrast credentials. Even with FALD set to maximum, the CX850 could not outdo the Vizio or the F8500. On the other hand, it performed at approximately the same level as those other two TVs, and looked much better overall than what I saw from the CX850 at the shootout in June.
Reviewing the CX850 was an eye-opening experience. Before I even touched the TV in my studio, I had already invested many hours in solving the riddle of how to get peak performance out of it. A TV should not be a puzzle box that requires a calibration expert to unlock. Even so, the TC-65CX850U is a great TV. In a bright room, playing 16:9 content, its picture is crisp and vibrant. However, it takes a lot of tweaking to get it to play a letterboxed Blu-ray movie in a dark room with the same overall image fidelity as a Vizio M65-C1—which sells for half the price. I wonder how many TV owners would bother to jump through the hoops needed to get the most out of the CX850?
Granted, the Vizio lacks support for 3D and can’t come close to the DCI/P3 color gamut, so the CX850 does offer a few features that its less-expensive FALD rival from Vizio cannot touch. The question is whether HDR and 3D offer enough benefit to justify paying twice the price for a 65″ FALD LCD. Personally, I have little interest in watching 3D at home, and I think HDR is a technology that will emerge as a must-have feature in the future—it’s just not there yet. Ultimately, if money is not a part of the purchase equation, the CX850 is a solid choice for someone looking for a premium 65″ UHDTV flat-screen TV.
If you have any questions, observations, compliments, or criticisms pertaining to this review, please leave a comment and I will gladly discuss it. Also, if you want to dive deep into the ongoing AVS Forum discussion of the CX850, you should check out the “Official TC-65CX850U Pro 4K Ultra HD Smart TV Owners Thread”
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