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LG LM670 (47LM670T) 3D LED LCD TV Review

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Will it be third time lucky for the Koreans?

by Mark Hodgkinson May 30, 2012 at 12:00 AM

  • TV review


    LG LM670 (47LM670T) 3D LED LCD TV Review
    SRP: £1,349.00


    It’s not been a great start to the new season as far as LG has been concerned and both the high-end LM860 and flagship LM960 had too many teething problems to justify an AVForums award. As Steve Withers commented in the LM960 review, it’s sometimes at the very top end of the market where LG seems to flounder perhaps as a result of trying to push the boundaries just a little too much. Although with their new OLED TV just unveiled this week in Europe, LG may just find themselves sitting proudly atop the premium TV market very soon.

    The 47LM670 sits in a sector of the market where LG seems to thrive, just above the middle. In terms of a feature set it lacks little from the higher end sets, with just a reduced backlight modulation frequency and dual core processing of any real note. Of course it’s one of LG’s Cinema 3D TVs and packs in all the Smart TV options we’ve come to expect, as well as the Magic Motion Remote Control to make their use more intuitive. There’s also a very fancy design, Freeview HD and built-in WI-FI to throw in to the list of enticements. Will it be third time lucky for LG? Read on to find out.

    Design and Connections

    The LG 47LM670T is a continuation of the ‘Cinema Screen’ design ethos designed to deliver pictures from corner to corner with only the minimum of bezel visible. The bezel isn’t as micro thin as that of the flagship 960 but we actually prefer the slightly more substantial 1cm black surround of the 670. We also like the silver trim that runs around the outer edges and under the bottom of the screen and, in fact, we genuinely prefer the LM670T’s base stand - that reminds us of a metallic link - to the ‘winged’ effort of the higher end TVs. It gives the 670T a much more refined, floating presence.

    The supplied standard remote control mirrors those in the upper tier TVs except it doesn’t have glow-in-the-dark buttons, nor a backlight to compensate. It fits very snugly in the hand and the new SETTINGS button is a real plus makes getting at the Picture controls far easier than in last years LG’s. There’s a recess to the rear for your index finger making it very comfortable to hold and all the buttons sit where you’d want them with the possible exception on the INFO button which is awkwardly placed to the bottom left.

    Also in the box is LGs redesigned Magic Motion Remote Control, that now features a very nifty little scroll wheel for zipping through the Home page. The design is extremely simple with just 9 buttons on the face including vol/channel up and down, Standby, 3D, Home and Back. We’re certainly not sold on it as a replacement for a conventional controller for ‘traditional’ TV activities, i.e. just watching the thing, but we’re converts when it comes to the Smart functions.

    The LG 47LM670T features the regular 4 HDMI side ports which are side-facing along with 3 USB ports and a CAM slot. The HDMI ports are 10cm from the edge of the bezel so you may need to consider angled cables or adapters for a tidy fit. Running across the downward facing connections panel there is a LAN port; D-SUB PC in with audio jack; the aerial connection; a headphone jack; connections for the supplied adapters for Scart, Component and Composite sources and an S/PDIF digital audio out.


    The Menus are largely same as those in the LM860 and 960 and that’s no bad thing as we’re big fans of the LG menu system, in most regards, except when it comes time to calibrate where the GUI can get in the way. We’ll run briefly over the Picture Options here.

    The LG LM670T has quite a number of Picture Modes – Intelligent sensor, Vivid, Standard, Cinema, Game, isf Expert1, isf Expert2 – with the isf and Cinema modes unsurprisingly providing the most accurate pictures out of the box. All the standard Backlight, Contrast, Brightness and Colour controls are present plus both vertical and horizontal Sharpness controls that we left at default in the Expert modes.

    The new 6-Axis 3D Colour Management System (CMS) is located in the Expert Control area of the Picture Menu along with both 2 and 20 point White Balance controls, some pre-set gamma curves and a choice of Colour Gamut options. Also, less usefully, in the Expert Control menu are the Dynamic Contrast, Super Resolution and Edge Enhancement options which were all set to ‘Off’. The Picture Options area houses settings for the Tru-Motion, Real Cinema and LED Local Dimming options that will be discussed later in the review, as well as a couple of noise reduction features we never found the need to engage.

    Note: We had to download a Software update for the Tru Motion controls to become apparent in the menus, so if your LM670 isn’t showing them you will need to update over the network or via USB from a file on the LG support website.


    Of all the 2012 models we’ve seen so far, we like LG’s layout for their Home page the best. It’s bright and colourful whilst at the same time not too gaudy with all the content clearly presented in a card style format. There are four cards for the Premium, 3D World, LG Smart World and Smart Share categories. Running along the bottom of the screen is a list of your favourite apps that can be added to and modified at will and is not limited to internet content.

    LG have upgraded their previous 3D Zone Smart TV app to become 3D World card and there are around 70 items to watch encompassing entertainment, sports, documentary, kids, and lifestyle. There’s most of the usual 2D video on demand suspects in there too but BBC iPlayer is not yet functioning with the 2012 LGs and Netflix has yet to be added but there’s the likes YouTube, Demand 5 and Lovefilm. There’s Facebook, Twitter and Skype video calling too provided the optional AN-VC400 camera/mic attachment is purchased. Users can hook up a hard drive to record from the internal tuners, engage in a reasonably non-frustrating spot of web browsing and, thanks to the built-in Wi-Fi, media streaming should be relatively easy to achieve for most and you’re not limited to files on a PC as the LM670 will happily communicate with smartphones and tablets provided they’re equipped with the relevant – and free – app.

    Test Results

    By opting for the isf ccc Expert Viewing Mode and the Rec.709 Colour Gamut in the Picture Menu, we were quickly at a point not too far off the industry standards. Light output was a bit too limited at the default setting of 30 for Backlight so we raised that, adjusted Brightness and Contrast to match the viewing conditions and maximise dynamic range and then took these measurements for greyscale and gamma:

    The results here are mostly very good but looking at the Gamma Point graph as individual channels, rather than the correlated line shown here, it’s easy to see that Red is being heavily clipped from 80% stimulus onwards. This is despite us having already lowered the Contrast control quite a few clicks to get rid of some visible discolouration from a white PLUGE pattern. It doesn’t overly impact the pictures which are already a little washed out from the general excess of blue and green energy but, at the least, we’d like to stop the clipping occurring as ‘early’ as it is. Gamma tracking is a little bit under our 2.2 target so we would have to see if one of the other pre-set curves would get closer.

    Referring to the CIE Chart and, again, overall it’s a good result for the LG 47LM670T but once more it’s problems with red that are causing the issues; it’s considerably off hue to the extent its visibly orange and as a result magenta is being pulled away with it, meaning it’s too purple. We do have a 6-Axis Colour Management System but the red problem may be out of scope for the panel.

    We had some problems with the 2 point white balance controls when testing a LM860 but here it was the turn of the 20 point sliders to throw a spanner in the works, as they were only effective with the in-built patterns and once you switched back to regular content, any changes effected were null and void. In all honesty, with Delta Errors almost all below 1 using the 2 point controls, it’s not a huge issue but frustrating nonetheless. By reducing the contrast further and changing the gamma to 2.4 we were able to largely nullify the clipping but at the expense of robbing some dynamic range from the picture.

    As we suspected it wasn’t possible to fix all the errors with red, which points to a limitation of the panel and it remained on the orange side despite our best attempts to pull it away whilst maintaining respectable levels of saturation and luminance. In all other respects the CMS had worked well and the large hue and luminance errors in magenta were able to be corrected but owing to the large amount of red energy in that secondary, we weren’t able to fully saturate. It’s a very good result here for the LM670 but we’d ask LG to get the red pixel right next time.

    Picture Processing

    The LG 47LM670T appears to have inherited most of the good habits displayed by the LM860 and LM960 that went before it but there are certainly some issues with elements of the picture processing. In fact, the LM670 actually flies through most of the standard set of testing and scaled standard definition extremely crisply, picked up on nearly every film cadence thrown at it and deniterlaced video content in both SD and HD signals extremely well but certain patterns did highlight issues they’re not really intended to show.

    The Jaggies test on both the Spears and Munsil and HQV discs displayed a lot of artefacting on the moving bar when the signal was set at 50Hz, which bore out our experiences with watching fast paced sports from a 1080i50 broadcast source. With real world content that would manifest as black trails and ghosting artefacts. We’re used to seeing these kind of effects when motion interpolation engines are used but the Tru Motion settings had been left off for these tests. Interestingly, switching the signal to 60Hz instantly cleaned up the artefacting and points to issues with the 50Hz processing. LG, themselves, think the trailing issues are as a result of some problems with the overdrive technology implemented, which is kind of ironic given overdrive is intended to improve panel response and thus motion clarity.

    It didn’t stop there, unfortunately, and there were also issues with 1080p24 playback, i.e. most Blu-rays. The LM670 had real issues with the Wedge Pattern test on the Spears and Munsil disc with the 24p cadence, not something we observed with the LM860V that was recently here for testing. The pattern is made up of two wedges made up of alternating fine black and white lines that move around the screen. The lines are supposed to stay stable as they move but the 670 displayed very noticeable ghosting, flicker and trailing. Obviously the test is torturous and very high contrast – bright white against black – but it does indicate there would be issues with real world content too. Popping in a selection of Blu-rays with a lot of dark scenes and we found the manifestation of trailing in a couple of night time firefight scenes from the HBO Pacific Blu-ray Box set where objects moving across the blackened skies would visibly ‘feather’. Again, forcing the Blu-ray player in to 60Hz output cleared up the problems but we’re not keen on the telecine judder it induces. We don’t want to highlight this as too large an issue, it’s not going to be visible on the vast majority of scenes but it is there. In fact we found the problems at 50Hz more severe given they weren’t restricted to extremely high contrast situations.

    Gaming Performance

    Before we updated it to the latest software version, the 47LM670 we were testing had a very respectable lag of around 45milliseconds to controller input. Unfortunately, post 03.03.31 software update, that time increased to nearer 68milliseconds, putting it at the higher end of the TVs we’ve tested with the new LagTest device. Hopefully a software upgrade can reverse the process. Note, results are the same with HDMI input labelled as PC or Game.

    Energy Consumption

    We averaged the LG 47LM670 to be drawing just 58W in calibrated 2D mode and 75W in default standard 3D mode.

    Picture Quality – 2D

    Like the LM860 and LM960 that went before, the LM670 isn’t going to set the word alight with its contrast ratio numbers but we did see a definite improvement over the LM860 in other areas. For those interested, we took a black level measurement at 0.11cd/m2 without the local dimming engaged to a calibrated peak light output of around 120 cd/m2 on a 4x4 ANSI checkerboard pattern. Unlike the 860, we didn’t find the local dimming to cause particularly obtrusive haloing and it enhanced the uniformity from a light pooling standpoint, not that it was bad in the first place; so with local dimming at medium (high crushed too much detail/low was no real improvement over off) we measured black at 0.085cd/m2, which is an improvement over the ‘native’ capabilities of the panel and certainly respectable in a typical living room scenario, particularly as the filter is well capable of hanging on to the blacks under testing conditions. Shadow detailing was also mediocre with shades near black barely distinguishable from one another, particularly when any bright content was on screen.

    What the LG LM670 does do well is colour, slight orange tint to reds excepted, and the calibrated picture packed plenty of believability in to skin tones and land and skyscapes. Despite the lack of oomph from the black levels, images had plenty of stand-out quality thanks to the flat gamma response and we genuinely enjoyed viewing some material. The motion issues with 50Hz material mentioned on the test results page could intrude on to faster paced action and the Tru-Motion settings did nothing but add a soap opera effect over the top of the trailing. Similarly the 24p problem is likely to distract from time to time but we don’t want to overblow it and it’s not something owners will constantly be plagued by. Still, these are things that LG needs to address as there are plenty of TVs out there that don’t show these problems.

    It’s a shame about the niggles as generally screen uniformity was pretty good and the prospect of crippling dirty screen effect - our biggest fear going in to the review process – was largely unrealised. We could see the panel array under fast panning on very light sections of the picture but that could be said of just about every LED TV out there. As can be expected with an IPS panel, viewing angles are very generous especially in terms of the colours maintaining fidelity but expect some contrast to be lost when viewed from the sides. Whilst the filter was very good, the LM670 doesn’t handle reflections particularly well. It’s a difficult call for manufacturers who seem to face the choice between allowing the screens to reflect clearly or employ some kind of diffusion that spreads the reflections around and doesn’t give their form clear definition. LG have chosen the second approach with the result that daytime viewing in the recent sunny weather has been nigh on impossible without drawing the curtains. Reflections are certainly indistinguishable as individual objects but that’s at the expense of taking the actual on-screen images with them in a blurry haze.

    Picture Quality – 3D

    As this reviewer generally finds with the passive approach, 3D images were fabulously bright, crosstalk and flicker free whilst not losing obvious detail or resolution when viewed from around 8 feet; a distance we’d suggest as sensible for 3D viewing to avoid feelings of discomfort with images with a lot of negative parallax (pop out). We couldn’t see the Black Matrix employed in the Film Pattern Retarder (FPR), commonly referred to as scan lines, from anything outside of 3 feet from the screen and we found the whole 3D experience to be thoroughly engaging. We realise some don’t like passive technology, for one reason and another, but if you’ve yet to see it and were previously discounting it on the grounds of ‘reduced resolution’, we’d urge you to go and see it with your own eyes.


    OUT OF


    • Lots and lots of well presented features
    • Very nice calibrated colour reproduction
    • Excellent viewing angles
    • 3D is fabulous
    • Some very good video processing
    • Magic Motion remote control


    • Motion artefacting/trailing in 50Hz content
    • Problems with high contrast scenes with Blu-ray
    • Mediocre dynamic range and shadow detail
    • Input lag still too high
    • Some panel banding/dirty screen effect
    You own this Total 0
    You want this Total 0
    You had this Total 0

    LG LM670 (47LM670T) 3D LED LCD TV Review

    It’s a shame we’ve had to devote so much page space to a few issues that come along with the LG 47LM670T as, but for a couple of problems that can really hamper the immersion, it’s actually quite a capable mid-range TV. The problems in question are seemingly panel driving related and we would be hopeful that LG can investigate and act accordingly in releasing a software update to address both the motion trailing issues with 50Hz content and the occasional inability to deal with high contrast material at 1080p24, i.e. most Blu-ray discs, in similar fashion. We would certainly consider the former problem the most intrusive for day to day use but that doesn’t mean the latter can be disregarded, particularly for big movie watchers. Most of the rest of the package was very impressive; an accurate colour palette with even toning, excellent video processing, comparatively good screen uniformity and an excellent range of Smart TV features - all wrapped up in the best GUI we’ve seen to date - will mean the LM670 will certainly find favour with some but, ultimately, we feel that LG needs to address the two highlighted issues, in particular, to meet the needs of the videophile shopping in this market sector.

    We found the winged stand found in the higher-end LG LM960 and LM860 didn’t really tickle our fancy but the ‘Ribbon’ of the LM670T is clever bit of design that gives it a very convincing floating look, an idea that seems to be very in vogue with TV designers this year. We liked both the standard remote and the magic motion remote controller, although the latter is best saved for Smart TV duties, of which there are legion. The ‘Card’ system employed on the Home Page makes zipping through the myriad activities a breeze and one can go from browsing the web to streaming 3D content in the time it takes to rotate the scroll wheel on the ‘magic’ controller. You can stream your media files from your home network through the built in Wi-Fi, make recordings from the internal tuner to a USB connected hard drive and even connect your mobile device via apps for iOS and Android. If all that is not enough, the owner can communicate via Twitter or Facebook or, more personally, via video chat through the Skype app.

    It’s a little unfortunate that the 20 point white balance controls seemed only effective for the built in calibration patterns but we were still able to extract nigh-on reference greyscale and gamma results. The same can be said for the colour calibration that would have hit reference status but for the panels seemingly inherent orangey reds. Bar the aforementioned panel driving problems, the video processing of the LG LM670 was nothing short of excellent with superb cadence detection, keen deinterlacing and sharp scaling. The software update that enabled the Tru-Motion controls to appear in the menu brought about an unwelcome increase to input lag, for whatever reason, and we wished they’d never bothered as we never could find a happy place with LG’s interpolation engine. The numbers for energy consumption were a darn sight more impressive, however.

    The LG 47LM670T is a frustrating little beast. With so much to offer, it’s a shame it lets itself down on what should be fairly routine tasks. In terms of price to performance, we feel the 670 offers a better alternative than either the LM860 or LM960 that went before but it doesn’t quite do enough to gain a badge. If LG can fix the two big issues, we’d happily reconsider.

    Suggested retail price when reviewed: £1,349.00

    The Rundown

    Contrast/Dynamic Range/Black Level


    Screen Uniformity


    Colour Accuracy


    Greyscale Accuracy


    Video Processing


    Picture Quality


    3D Picture Quality


    Sound Quality


    Smart Features


    Build Quality


    Ease Of Use


    Value for Money




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