What is the Panasonic GX800?
As well as the dynamic metadata systems, the HDR performance of the GX800B series TVs will depend on how well the edge lighting and dimming work together. Being edge-lit, the design of the Panasonic TX-58GX800B is super slim when compared to competing LCD TVs, with high-quality plastics and a metal stand.
The HCX (Hollywood Cinema eXperience) image processor is also onboard the GX800B and is tuned by Hollywood colourists along with image processing, colour reproduction and black performance to produce the most cinematic images possible, according to Panasonic.
While there is no soundbar or upward-firing speakers built-in with the GX800, it is compatible with Dolby Atmos audio and the smart TV system has also been updated to My Home 4 with Freeview Play and all the latest VOD apps with 4K HDR support including Amazon, Netflix and YouTube.
The GX800 series of TVs is available in 40-, 50-, 58- and 65-inch sizes and it is the 58-inch version we are reviewing here. The sample was provided by Panasonic UK.
So given the technical limitations of LED LCD VA panels and edge lighting, can the Panasonic GX800B series TV make the grade? Let's find out
Panasonic GX800 LCD TV Video Review
Design, Connections and Control
The GX800 uses edge lighting for its VA LCD panel and this means that the panel depth is very thin. Not quite OLED degrees of thinness, but it gets close and the rear of the panel also follows recent OLED chassis designs with the bottom section sticking out further and housing the connections, electronics and speakers.
The 6mm bezel is slightly recessed from the panel around the top and sides, so it gives the edge of the screen an interesting design point. When this meets the bottom of the panel there is a 20mm solid bezel that runs the length of the bottom edge. There is a printed Panasonic logo in the centre of this with a power indicator led to the left bottom edge. You can switch off this LED completely or have it set for a number of options in the menu.
The stand is a metal plate with two rising legs that attach to the bottom of the panel. Down the back of each leg is room for cable management to give the TV a clean look from the front with no cables on show.
The clean design language continues around the back with the use of high quality sculpted plastics adding a nice design touch. The connections and electronics are housed in the section that juts out with heat vents to the top of this section to help with cooling. There are VESA points for wall mounting and the power cable is a detachable figure of eight lead on the left side of the back panel. There are no covers for the connections section.
Overall, the design is modern and the build quality is good for the price point with high-quality plastics being used.
The outwards facing connections are a second USB port, third HDMI slot and digital optical output, component video input and one set of stereo audio RCA inputs. There are no satellite antennas, only an RF slot for terrestrial digital TV signals.
The three HDMI inputs all handle 4K 60P 4:4:4 signals and are HDCP 2.2 compliant with support for HDR10, HDR10+, HLG and Dolby Vision high dynamic range formats – more on this later.
If you have ever used a Panasonic TV in the last five years, you will immediately find the remote control familiar. It’s a black plastic affair with large buttons and a logical layout.
To the top, we have small buttons that cover power, picture, inputs, menu, text and apps.
The row below has Info and Exit keys along with the Netflix direct key, Home and Guide and below these the directional and enter buttons. We also have Option and back/return options with coloured keys, the volume and channel rockers, along with a Mute key in the middle. To the bottom, we have numerical keys, a direct Freeview Play key and player controls for HDMI CEC use with a Panasonic player or other device connected by HDMI.
Overall, the remote fits with the market position and price point of the GX800B and should last the lifetime of the TV.
The GX800 we are testing here is a 58-inch version that uses a VA panel with edge lighting and local dimming. This allows the TV to be as slim as it is, but can also cause issues with image uniformity given the edge lighting arrangement. Panasonic claims its HDR Bright Panel plus helps with this. We will cover this more in the performance part of the review.
The Panasonic GX800 also features the latest HCX picture processor, as well as picture tuning from Hollywood colourists, to produce the most cinematic image possible. Panasonic also claims that the GX800 has a Wide Colour Spectrum thanks to advanced colour reproduction methods as well as sports and games modes that are tuned to get the best out of these uses. However, a wide colour spectrum should not be confused with wide colour gamut (WCG) as we will point out in the measurement section of the review.
Finally, while the GX800 doesn’t feature a soundbar or upwards firing speakers like the top end GZ2000 OLED TV, it does support Dolby Atmos audio which you can take advantage of using the TV speakers, which are passable, but using an off-board audio system would be the best option to take full advantage of the sound.
We fully tested the GX800 using the latest firmware at the time of the review, which was version 3.676.
The colour gamut results for Rec.709 HD colour are affected by the cyan push with the saturation tracking points moving towards cyan, with the main issue being an undersaturation of red. Magenta has also introduced a large hue error which will also affect onscreen reds. However, once again these errors are much harder to actually see within onscreen content such as TV and film viewing, so we doubt normal viewers would ever see any issues with accuracy. As out of the box presets, the True Cinema and Warm 2 settings are very good for a TV of this price point and performance. Of course, we can calibrate the GX800 and we have very good calibration controls included within the menus.
Given the issues we also had with the out of the box colour gamut with the cyan push, correcting the greyscale has resolved those issues with colour points hitting most of their saturation points or getting extremely close. The 100% points are off and cannot be adjusted as those are the native points of the panel being used, but we rarely have any primary colour at 100% intensity in any TV or film content, so this is not really an issue. More important is the 75% and below points, which actually make up the image we view most often and here the GX800 is accurate enough to the Rec.709 gamut after calibration.
Our overall results are close to reference with an average DeltaE of 1.2 for our greyscale and gamma tracking and within a Rec.709 colour checker, an average of 1.25 – so both results are well under the threshold of 3.
Looking at the EOTF results we can see that the GX800B has a reduced peak brightness so the tracking is a tad high for the main PQ standard and then rolls off pretty steeply to try and fit as much detail and highlights within the available image brightness. This is obviously with static metadata HDR signals. The tone mapping is a little higher or brighter than normal and we presume this is to give the image a pop that makes up for the lack of peak brightness.
The Panasonic GX800B supports Dolby Vision and HDR10+ dynamic metadata systems and here the tone mapping and performance is vastly improved, even with the same restricted contrast and peak brightness. We will cover this more in the performance area of the review.
LED LCD TVs have been around for quite some time now and they have well known technical drawbacks. The GX800 is an edge lit TV, which means it has to spread the light from the edge to fill the entire screen and this will impact on the panel uniformity. In the case of the GX800 we found that the bottom screen corners were brighter than the rest of the screen and in a pitch black room with local dimming switched to off, the backlight was patchy and inconsistent. This did improve with the local dimming engaged. The Sharp TV next to the GX800 uses a direct LED backlight but it has no local dimming control and its contrast is only half that of the Panasonic.
On the GX800 we did notice some banding and mild dirty screen effect with content that had one colour filling the majority of the screen, like football or blue skies. Within dark scenes it was also possible to see the lighter bottom corners. Viewing angles were also poor with colour shift and contrast issues from as little as 20 degrees off axis as, after all, this is a VA panel. However, most of these issues are related to the technical limitations of LCD TVs and something all buyers must be aware of when considering such a TV. These are also issues that are more noticeable when using the TV in a pitch-black room. Not all LCDs are light cannons with HDR content, and at under £1000, this is evident when the GX800 is in the most accurate picture mode with a peak brightness of just 300 nits.
The advantage here with the GX800 is that it accepts both HDR10+ and Dolby Vision dynamic metadata standards, which are best suited to TVs like this Panasonic. The metadata provides the TV with scene by scene information on maximum brightness and the GX800 then maps the image to its image capabilities to provide the best possible HDR image. With such material, the GX800 does provide a very decent HDR image that, while not as bright as the more expensive OLED and LED LCDs out there, for the price point does look very good when viewed in a normally lit room and from directly in front of the TV.
With the more common HDR10 static metadata content, the Panasonic does struggle a little more in providing as much detail in the brighter areas of the image but, at the same time, we found that when side by side with a Sharp LED LCD it has far more shadow detail and less clipping in the black areas of the image. The GX800 also has excellent colour reproduction when viewed from directly in front of the TV with skin tones looking natural and lifelike. The best out of the box settings for SDR and HDR content get pretty close to the standards with strong colour reproduction and decent black levels. The GX800 is best suited to rooms with some ambient lighting or bias lighting and not pitch-black rooms. In a suitably bright room with normal TV and streaming material, the Panasonic is capable of decent image quality with good upscaling and motion performance. Motion is strong with 24fps material looking very good with no frame skipping with Intelligent Frame Creation switched off. We didn’t notice any other obvious issues with frame skipping or dropping with IFC turned on, but artefacts are present with soap opera effect in the higher settings. However, overall, we found motion to be very good indeed for this level of TV. Upscaling was also good with no obvious issues with line ringing, but it is a little soft looking with 576i and 1080i broadcast content, and nice and detailed with Blu-ray material.
In side-by-side testing with a similarly priced Sharp TV with a direct LED back light, the Panasonic was strong in all image areas, with the most accurate blacks, mid-tones and highlights, along with better above black detail retrieval and far superior contrast and colour performance. The Panasonic is a couple of hundred pounds more expensive than the Sharp but shows that, when engineered properly, the edge lit GX800 with its local dimming is far superior in terms of dynamic range and contrast over the direct lit Sharp, but also Panasonic’s expertise in colour also shines through. However, it should be noted that the GX800’s colour reproduction does not fully cover the wide colour gamuts of 4K as it stands, but at the price point it certainly offers superior accuracy over some of its peers, especially the Sharp next to it which has a yellow tint even after calibration.
As we have said a few times, the technology being used does cause some issues that impact on performance when used in a pitch black viewing room, the edge lit GX800 is a good quality LED LCD TV for use in a normal living room and, in its most accurate picture modes and watched from directly in front of the TV, it provides a very accurate image for most normal users. As a dedicated TV for movie watching in a dark room the GX800 does have its technology drawbacks with blooming, DSE and uniformity issues, but in normal viewing conditions with normal lighting, you would be hard pushed to notice this and the image quality is very good at the price point. Off axis viewing at more than 10 degrees does introduce navy looking blacks and bottom corner brightness issues.
HDR is a little dimmer than more expensive models, but given the use of HDR10+ and Dolby Vision dynamic metadata systems, the Panasonic is capable of producing dynamic images with highlights and details in brighter areas of the image visible, but with an overall dimmer APL in comparison to the more expensive OLED and LCD screens. Colours, on the other hand, are superb in HDR playback modes for the price point and, added to good SDR and decent image quality in normal viewing conditions, the GX800 gives an honest account of itself. Black levels are not inky black, but they are consistent and black bars appear as black and there is no blooming lighting up the bars. Greys are good with decent shadow detail retrieval and detailed mid-tones add to the decent contrast levels. This is no OLED when it comes to image dynamics and black levels, but for an LCD TV with edge lighting in normal viewing conditions, the GX800 offers a decent performance for the majority normal users.
If you are using a Panasonic 4K player with HDR10+ and Dolby Vision capabilities, like our UB820, you may need to make some menu changes with dual discs that handle both formats. Our disc of Alita defaults to HDR10+ and there is no switching available in the disc menu to select Dolby Vision, so you need to switch off HDR10+ either in the TV menu or disc player menus. Remember to switch back when you’re finished if you want HDR10+ playback.
- Dolby Vision and HDR10+ dynamic metadata helps improve the HDR performance to fit TV capabilities
- Colour reproduction is very good
- SDR content looks accurate
- Decent above black and mid-tone details
- Excellent motion and video processing
- Excellent upscaling
- Edge lighting adds uniformity issues
- Mild DSE and patchy backlighting
- Blacks are not deep or inky, especially watching in pitch black room
- Bright bottom corners of the screen
- Very poor viewing angles
- Dim HDR performance
Panasonic GX800 (TX-58GX800) 4K LED LCD TV Review
As such, being built to a price point means that compromises have to be made with the type of backlight and other features. The use of edge LED lighting and a VA panel allow for a very slim design for an LCD TV, but in terms of performance, we do have a few drawbacks such as panel uniformity thanks to the backlight and the viewing angle limitations of the VA panel. However, the Panasonic GX800B is also one of the first TVs at its price point to feature both Dolby Vision and HDR10+ dynamic metadata systems, which can adjust the image performance to get the best possible HDR image from the GX800. Static metadata HDR10 content does however look a little dim due to the lack of total peak brightness.
As a TV for watching movies in the pitch dark, this model struggles to produce deep blacks and with the edge lighting and panel uniformity is patchy at best. However, watching in a room with ambient or bias lighting can mitigate these issues. As such, we would recommend using and watching the GX800 in normal lighting to get the best performance without introducing obvious issues. Watching directly in front of the TV gives the best results for colour reproduction, which is very good for SDR and HDR playback. Upscaling, motion and video processing are also excellent at the price point. Add to this a basic but stable smart TV system with Freeview Play catch-up and HDR capable playback from Amazon, Netflix and YouTube apps and, for the £899 price point at the time of this review in August 2019, you have a very good LCD TV package.
Coming back to our point that there is no one TV that does everything to perfection, what we have here is a TV that is designed for a market position, driven by price, and trying to get the best performance at that level, given the technology and its flaws. As such, if you stay away from watching off-axis and in a pitch black room you can avoid the main issues with the Panasonic GX800B and, in return, you get a very good SDR picture performance and HDR that is the best you will get from an edge lit TV at the current price point.
Thanks to working with both dynamic metadata HDR10+ and Dolby Vision systems, the GX800 can provide images without clipping details in the blacks or highlights. They are not close to the brightest or most dynamic HDR images available in more expensive TVs, but they are consistent and detailed without the flaws of dim looking static metadata HDR images. Plus, with Amazon providing both HDR10+ and Dolby Vision for some of its content, along with Netflix supporting Dolby Vision, you already have a decent library of suitable dynamic metadata content to watch on the GX800.
Overall, taking in to account the compromises, technical limits and the performance on offer - the Panasonic GX800 is a solid mid-market TV with strong SDR picture quality along with HDR10+ and Dolby Vision dynamic metadata picture quality to match the TV's performance capabilities.
Contrast/Dynamic Range/Black Level
SDR Picture Quality
HDR Picture Quality
Picture Quality Out-Of-The-Box
Picture Quality Calibrated
Ease Of Use
Value for Money
Our Review Ethos
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