Philips 272P4APJKHB (272P4APJKEB)

Responsiveness

Input lag

We used SMTT 2.0 (specialist software) alongside a sensitive camera to compare the latency of the P272P4APJKHB (P272P4APJKEB) with a range of monitors where the input lag is known. Using this method and taking over 30 repeat readings we calculated 19.80ms (just over 1 frame) of input lag for the Philips. This is influenced by the element you see (pixel responsiveness) and also the primary element you feel (signal delay). This is indicative of a moderate signal delay, one which may bother some users but that shouldn’t bother others.

Perceived blur (pursuit photography)

Our article on responsiveness explores a number of important concepts related to monitor responsiveness. A key concept is that it isn’t just pixel responsiveness that dictates how much motion blur you perceive when viewing moving content on a monitor, but also the movement of your eyes. Both influences can be captured using a technique called ‘pursuit photography’, which uses a moving rather than stationary camera to simulate eye movement. This also highlights other weaknesses such as PWM artifacts and overshoot (inverse ghosting).

The following images are pursuit photographs taken with the aid of the UFO Motion Test for ghosting, running at 960 pixels per second. This is a practical speed for taken the photos and also highlights the aforementioned factors nicely. The ‘medium cyan’ background (middle row of the test) is used here with all ‘SmartResponse’ pixel overdrive settings of the monitor; ‘Off’, ‘Fast’, ‘Faster’ and ‘Fastest’. The final two pictures show a 60Hz reference screen, giving an indication of how things should look if pixel responses aren’t a limiting factor. The first of these reference images has the reference monitor (Samsung S27A750D set to its ‘Faster’ response time setting) running at reduced brightness and therefore using PWM to regulate backlight brightness. The second reference image shows the Samsung running at ‘100’ brightness and therefore avoiding the use of PWM (‘DC Dimming’ instead).

Perceived blur with various settings

You can see that, regardless of ‘SmartResponse’ setting, the object and any additional trailing appears quite heavily fragmented. This is due to the use of PWM for backlight modulation as mentioned previously. Using ‘SmartResponse = Off’ you can see a significant degree of trailing behind the object. The ‘Fast’ setting reduces this trailing significantly. The ‘Faster’ setting, meanwhile, introduces obvious inverse ghosting (overshoot), as brightly coloured trails behind the object. It does appear to cut down on some of the ‘conventional trailing’ as well – but the fragmentation remains. The width of the object appears narrower in this photo, but it appears that the camera has focused differently in this instance. The main purpose of this photo was to show the introduction of the overshoot, however. With the ‘Fastest’ setting the overshoot is increased and is now extremely bold and noticeable.

From this analysis it is clear the ‘Fast’ provides an optimal balance of pixel responsiveness without the unwanted side-effect of obvious overshoot. This is clear when testing the monitor more broadly, for example when gaming. We provide a thorough subjective analysis of the response behaviour of the monitor in the following section, complete with an analysis of how the PWM artifacts manifest themselves and the effect they have on the experience. We will not be including a section on ‘overclocking’ in this review as we were only able to set the monitor as high as 66Hz comfortably (i.e. without significant frame skipping or other negative consequences). This applied regardless of the connection used, and really setting the monitor to 66Hz compared to 60Hz provides little real benefit.

Responsiveness in games and movies

On BF4 the majority of perceived blur came from eye movement and is as you would expect to see on what is technically a must faster 60Hz LCD. There was a degree of weakness in pixel responsiveness beyond this, however. There was a slight but not particularly pronounced degree of additional trailing in places. Perhaps more noticeable was a reasonably light overshoot in places, for example when trees or dark metal gun turrets were in the foreground and bright blue sky was in the background. This produced bright inverse ghosting, which could distract some users but wasn’t particularly pronounced or widespread really. It was certainly not as readily noticeable to our eyes as the artifacts associated with PWM usage. These artifacts were most noticeable on straight edges when moving past rapidly in a vehicle – there were obvious duplicated or split trails. On foot they are particularly noticeable on thin or brightly coloured objects, the best example being neon vertical strip lights running down skyscrapers on the multiplayer map Operation Dawnbreaker. If you move the mouse from side to side, they appear to fragment into multiple instances of each strip light.

On Dirt Rally these imperfections in motion performance weren’t so obvious and things generally looked as they would on the best 60Hz performers. There were hints of extra trailing and a little overshoot in places. The extra trailing was mainly confined to certain high contrast transitions, for example during the night stages where light shades (bright lights) moved against darker backgrounds. There wasn’t anything that really stood out and certainly nothing distracting when driving, beyond the blur from eye movement. The aforementioned PWM artifacts were also less noticeable than on BF4, as the movements tended to be gentler and more predictable and there weren’t really many thin objects that usually exaggerate the effect.

Finally we assessed the responsiveness of the monitor on our Blu-ray movie test titles. The pace of action here and overall fluidity is severely limited by the low frame rate at which the films run (around 24fps). As such the demands on the pixel responsiveness are much lower and the frame rate itself is really the underlying limitation. In other words, the performance was not hampered by slow pixel responses, overshoot or PWM artifacts – only the frame rate of the content itself.

Interpolation and upscaling

As an LCD monitor, the pixels are a fixed shape and size. The screen is designed to run optimally at 2560 x 1440, where everything that is supposed to appears sharp and clear. If you wish to run the monitor at a lower resolution, for example by connecting a games console or because you don’t have the graphical grunt to run certain games at 2560 x 1440 then you may wish to (or be forced to) use a lower resolution such as 1920 x 1080 (Full HD). The monitor can use an interpolation process to display these non-native resolutions. If you’re a PC user with a dedicated GPU, make sure that the monitor is going to be handling the scaling (interpolation) rather than the GPU as it will yield superior results.

AMD GPU users need to open Catalyst Control Centre and navigate to ‘My Digital Flat-Panels – Properties (Digital Flat-Panel)’. Ensure ‘Enable GPU scaling’ is unchecked (not ticked) and hit apply if this box was originally checked and you have unchecked it. Nvidia users should open Nvidia Control Panel and navigate to ‘Display – Adjust desktop size and position’. Ensure ‘No scaling’ is selected and ‘Perform scaling on:’ is set to ‘Display’. This is shown in the image below.

When interpolation is used on the Philips to display 1920 x 1080 (Full HD), it actually does quite a decent job at maintaining a decent degree of sharpness. If you compare it side-by-side to a native 27” Full HD display, text generally looks a bit softer and bolder but not as blurry as on some WQHD models using such interpolation. If you open a game or look at certain images you will see that things are a bit softer, they just look less ‘crisp’ and well-defined. Again, this is less extensive softening than seen on some WQHD models which make things look like they’re being observed through a soft-focus lens. In short; the Full HD resolution is useable but not displayed as well as it would be natively. If you leave the monitor running at 2560 x 1440 and display lower resolution content, such as viewing a Full HD movie on the PC, the monitor does not handle the scaling. Instead the GPU or software you’re using will automatically upscale, leading to a slight softening but one that is really quite subtle and some users won’t even notice. The monitor is therefore fine to use for watching Full HD content such as Blu-rays and other movies from a ‘sharpness’ perspective.

Conclusion

The Philips 272P4APJKHB may not look flashy and modern, but inside the monitor itself there is certainly some modern technology. With its AHVA panel and RB-LED backlight, it’s designed to provide accurate colour output over a wide colour gamut. From the perspective of our testing, which included game and movie titles predominantly, this extended gamut is not really ideal as it simply isn’t supported by such content at the moment. The look that it gave some elements of games and films was unmistakably vibrant and rich, but also inaccurate. Some may like this look, but others will not. For users who are specifically working within the Adobe RGB colour space or a similar gamut, though, this capability will be highly sought-after.

Straight from the box the gamma tracking of the monitor was excellent, with the flexibility to adjust it in the way that is promised in the menu system. The same can’t be said for the colour temperature, however. This was way off target and there was an underlying cool-green tint. Fortunately this could be tackled effectively by making the right adjustments to colour channels; something that a colorimeter, spectrophotometer or similar device will greatly help with. Unfortunately the uniformity of our sample was quite poor, though, and that isn’t something that can be compensated for by a colorimeter. There is a ‘SmartUniformity’ setting that would offer a better base of calibration if uniformity is particularly important for your work, but the colorimeter will definitely need to do some work on the colour channels if our sample is anything to go by.

The contrast performance was much as expected overall, with respectable static contrast and the usual ‘AHVA glow’. Despite it being initially marketed as ‘flicker-free’, the monitor uses PWM (Pulse Width Modulation) at any brightness below ‘100’. This isn’t something that will bother all users, but we did readily notice its effect on motion performance with the introduction of ‘PWM artifacts’. The responsiveness was otherwise pretty good for a 60Hz monitor. Input lag was moderate and pixel responses were quite well balanced using the optimal ‘SmartResponse’ setting, overall. Overall this monitor is a solid package (and not just because of the robust chassis) with some useful features and capabilities for some users. If you’re one of those users, we’d certainly consider putting this one on the shortlist.

 

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