Philips 276E6ADSS

Responsiveness

Input lag

A sensitive camera was used alongside a small tool called SMTT 2.0 to measure the 272E6ADSS’s input lag. This method compares the screen with a number of others with known latency, taking 30 repeat readings to try to maximise accuracy. Using this method we calculated 5.15ms (between 1/4 and 1/3 of a frame) of input lag. This value is influenced not only by what you ‘feel’ (the signal delay) but also what you ‘see’ (the pixel responsiveness). It indicates a low signal delay which shouldn’t specifically bother even sensitive users.

Perceived blur (pursuit photography)

This article looks at a number of important factors which influence the responsiveness of a monitor. Chief amongst these concepts is ‘perceived blur’, which the movement of your own eyes is a key contributor to. Pixel responsiveness also contributes to this, but is generally the more minor component. A technique called ‘pursuit photography’ is also explored in that article, which uses a moving camera to capture the motion performance on a monitor in a way that reflects blur due to eye movement and also pixel responsiveness.

The images below are pursuit photographs taken using the UFO Motion Test for ghosting. The test was run at 960 pixels per second, which is a good practical speed for such photography. The medium cyan background (middle row of the test) was used here with all ‘SmartResponse’ pixel overdrive settings tested; ‘Off’, ‘Fast’, ‘Faster’ and ‘Fastest’. Two reference images are also shown, indicating roughly how things look where pixel responsiveness isn’t a limited factor. The first reference image shows a Samsung S27A750D set to a brightness level lower than ‘100’ so that PWM regulation is used to dim the backlight. The second reference image shows the same Samsung monitor running at ‘100’ brightness, so that DC rather than PWM regulation is used for the backlight.

Perceived blur with various settings

From the images above you can see that the object appears fragmented rather than appearing as a smooth blurred object. This is due to the use of PWM for backlight regulation, which was pointed out previously. The fragments are finer and more numerous than the PWM reference image at the bottom left, as the frequency of the PWM is 240Hz (at 60Hz) rather than 180Hz. In addition to the fragmented appearance of the object you can see a degree of trailing. With ‘SmartResponse’ set to ‘Off’ this is visible as conventional trailing behind the object, but this is not actually particularly extensive and indicates that grey to grey acceleration is still used even with this setting disabled. As the ‘SmartResponse’ setting is turned up, overshoot (inverse ghosting) is introduced. Even at ‘Fast’ you can see this to a degree, but it becomes more pronounced with the ‘Faster’ setting and very obvious with the ‘Fastest’ setting. In practice the ‘Off’ setting was optimal as even at ‘Fast’ the overshoot is obvious and to some would be quite distracting during some transitions.

As you can see in the image and our reference to PWM frequency above, the monitor was also tested at 80Hz (with ‘SmartResponse’ set to ‘Off’). You can see that the object itself becomes a bit narrower, particularly the legs and cockpit area. The blur attributable to eye movement is cut down as you’d expect for an increase in refresh rate, but the additional trailing from slower than optimal pixel responses remains. This is not changed by the increase in refresh rate. The object again appears fragmented, but these fragments are even finer at 80Hz compared to 60Hz. That is because the PWM frequency is raised to 320Hz. In addition to perceived blur being reduced, the monitor also feels more responsive at 80Hz compared to 60Hz, increasing the ‘connected feel’. The delay between frames has been reduced, with up to ~1.33 times as much visual information displayed to the user every second.

Running a custom resolution (overclocking)

The monitor will comfortably run at up to 80Hz at 1920 x 1080 when connected by HDMI. By ‘comfortably’ we mean that there was no measurable or observable change to image quality (gamma, colour temperature, contrast etc.) and no frame skipping – it is therefore ‘true 80Hz’. This was all achieved by setting a ‘custom resolution’ using default timings. It’s quite a straightforward process with various methods to achieve this highlighted in the video below. As we were using an Nvidia GTX 980 Ti, we simply set the custom resolution up in Nvidia Control Panel.

With this sort of ‘mild’ overclock, as we’d call it, there is minimal risk involved and in all likelihood the monitor will last for its useful life in much the same way as if it was run at its native 60Hz refresh rate. Even so, as with any form of overclocking you’re doing this at your own risk. The risk may well be very low, but we accept no liability should anything happen to the monitor which may or may not be due to running it at an increased refresh rate. It’s also worth noting that we can’t guarantee every unit and every system will reach 80Hz. For the purposes of this review, including the section that follows, the monitor was run at 60Hz as normal.

Responsiveness in games and movies

On Battlefield 4 (BF4) there was a moderate degree of blur, with eye movement being the dominant factor here. Things therefore appearing quite similar to LCDs, regardless of response times. There were some weaknesses in pixel responsiveness which gave a bit of trailing beyond this, though, contributing to a bit of extra perceived blur in places. This wasn’t particularly obtrusive or obvious – there was no noticeable overshoot, thankfully. It was clear that fairly effective grey to grey acceleration was being used even with ‘SmartResponse’ set to ‘Off’. More obtrusive to our eyes, though, were artifacts associated with PWM usage. As shown in the TestUFO captures earlier, objects appear to break up into fragments. This was most obvious when driving around in a nippy vehicle such as the ATV – leaves on trees, tree trunks and other objects (particularly with relatively straight vertical lines) appeared duplicated during motion rather than a smooth blur being apparent. This was also evident for thin objects (vertical lines) whilst moving around on foot, including HUD elements if the mouse is moved from side to side.

Dirt Rally provided a similar experience in terms of pixel responsiveness. There were some imperfections here and there, but eye movement was by far the most dominant factor when it came to perceived blur. PWM was of course still in use all the same and artifacts were visible in places, but the generally gentler and more predictable movements on this title helped keep these at bay to a large extent. There also weren’t so many thin objects, although if you did observe some (fence posts, certain sign posts etc.) then the fragmentation could be seen. There was no observable overshoot, which is good.

We also assessed the motion performance on our Blu-ray test title. The pace of action was limited by the frame rate here (~24fps) and there were no real weaknesses evident that wouldn’t be evident on any other 60Hz LCD. Pixel responses were more than snappy enough for this pace of action, without any observable overshoot. The PWM artifacts could not be readily observed, either, due again to the slower pace of action and the fact that it is already fragmented in some respects by the frame rate being so low.

Conclusion

The Philips 276E6ADSS features a new type of backlight that we haven’t come across up until now, combining LEDs with a rail of Quantum Dots rather than the usual phosphor coating. The whole point of this technology is to allow a monitor to yield a wide colour gamut without the relative cost and complexity of competing solutions (such as GB-LED and RB-LED). The colour gamut of the screen was indeed massive, exceeding Adobe RGB in many areas and dwarfing the standard sRGB colour gamut. Unfortunately, the monitor did not provide any means to cut down on this colour gamut as it lacked any sort of emulation mode for the sRGB or Adobe RGB colour space. For users wanting to work with Adobe RGB content, the rather comprehensive coverage should do the trick. sRGB content, though, looked noticeably oversaturated and without any emulation modes this isn’t something that calibration with a colorimeter can fix. Some users do of course like this highly vibrant (if unrealistic) look and the monitor did still benefit from the strong colour consistency and shade variety of its IPS-type panel. Our unit also suffered from issues with white point uniformity, actually being the weakest in this respect that we’ve seen on any model we’ve tested.

The contrast performance was quite in-line with what you’d expect from a modern IPS-type panel, with static contrast just a touch weaker than on some we’ve tested recently. The usual ‘IPS glow’ also featured prominently, drowning out some low-end detail peripherally. The screen surface was not as ‘light’ as we’ve seen on some models, including any wide gamut alternatives with GB-LED backlight solutions, but the screen surface remained relatively smooth rather than obtrusively grainy. We were also a bit disappointed to see that the backlight was PWM-regulated, given the prevalence of flicker-free alternatives at the moment. It almost seems a bit of an oversight to launch a new backlight technology and then resort to using a regulation method (PWM) that most in the industry have turned their backs on.

In terms of responsiveness the use of PWM was really the main issue that separated this from many other 60Hz models we’ve tested recently. The artifacts this induces during motion are a bit unsightly, although sensitivity to such things does vary. As long as the not-so-aptly-named ‘SmartResponse’ setting was left off, there was no observable overshoot. Meanwhile the level of acceleration used provided only a bit of trailing on top of the blur perceived due to eye movement. So in that respect the monitor was fairly well (although not perfectly) balanced. There was very little input lag to speak of from the monitor, thankfully, and a nice little bonus was that this model (at least the unit we tested, on our system) ran happily at 80Hz as well.

The Philips is certainly an interesting model, showing that a wide colour gamut can be achieved without a particularly complex or costly backlight arrangement. But there are certainly some shortcomings when compared to more expensive models with wide gamut capabilities, such as the Dell UP2716D. The use of PWM for backlight regulation, lack of emulation modes to cut down on the native colour gamut are perhaps the most prominent issues. Then there is the relative lack of ports, lower resolution, lack of ergonomic flexibility and VESA mounting. Plus the fact the monitor is white – something that some will admire, but others will find quite off-putting. So it’s not a perfect monitor by any stretch of the imagination, but it’s nice that some users with a limited budget will now find the Adobe RGB colour gamut is within their reach.

The bottom line; an interesting showcase of new technology that makes the Adobe RGB colour gamut affordable – but this comes with some compromises along the way.

 

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