Philips BDM4037UW

Responsiveness

Input lag

A sensitive camera and a small tool called SMTT 2.0 was used to measure input lag for the BDM4037UW. The monitor was compared to various screens of known latency, taking over 30 repeat readings to maximise accuracy. Using this method, we calculated 11.35ms (under 1 frame) of input lag. This value is influenced both by the signal delay (element you ‘feel’) and pixel responsiveness (element you ‘see’). It indicates a fairly low signal delay, significantly lower than this model’s predecessors. This particular aspect therefore shouldn’t impede the experience for most users.

Perceived blur (pursuit photography)

In our responsiveness article, we look at the key factors affecting monitor responsiveness. One of the main concepts explored here is ‘perceived blur’, contributed to by both the movement of our eyes as we track motion on the screen and the pixel responsiveness of the monitor. We also delve into a photography technique called ‘pursuit photography’, which uses a moving rather than static camera to capture motion on a monitor in a way that more accurately reflects what the eye sees. Both elements of perceived blur (pixel responsiveness and eye/camera movement) are reflected.

The following images show pursuit photographs taken using the UFO Motion Test for ghosting, with the test running at its default speed of 960 pixels per second. This is a good practical speed for taking such photographs and one which represents both elements of perceived blur nicely. The monitor was set to its various ‘SmartResponse’ pixel overdrive settings; ‘Off’, ‘Fast’, ‘Faster’ and ‘Fastest’, respectively. The middle row of the test (medium cyan background) was used here. There is also a 60Hz reference shot, showing how things should look at 60Hz where eye movement is the only real contributor to perceived blur. This is a Samsung S27A750D set to full brightness (eliminates PWM dimming of the backlight) and using its optimal response time setting. The final image shows the Philips BDM4065UC, an interesting comparison to make as it is one of the predecessors of this monitor. Note that the horizontal interlacing patterns on these photos are moiré from the camera, not artifacts from the monitor. Also note that the test runs at a frame rate matching the monitor’s refresh rate (i.e 60fps), with the UFO moving from left to right across the screen.

Perceived blur with various settings

With ‘SmartResponse’ set to ‘Off’, you can see that the UFO itself looks soft and poorly focused. The lack of sharp focus and detail reflects perceived blur due to eye movement – refer to the 60Hz reference. There is also an unmissable bold trail, appearing quite black and inky behind the UFO itself and appearing as a yellowish-green behind the UFO body. This is trailing (or perhaps more accurately smearing, in this case) from the slower than optimal pixel responses. This is actually the most significant trailing we’ve captured using pursuit photography on any monitor, certainly for the medium cyan background (middle row). If you compare this to the Philips BDM4065UC (final shot) you can see that the trailing is far more extensive. The nature of the trailing is quite different on the BDM4065UC because it is fragmented due to PWM usage and also there is some overshoot (inverse ghosting) in the mix. But there is no extensive smear as shown on the BDM4037UW.

Setting ‘SmartResponse’ to ‘Fast’ doesn’t really change things in a positive way here. It actually boldens the trail a bit and makes it appear a bit dirty due to the introduction of some overshoot. The ‘Faster’ setting doesn’t really change much for these transitions, whilst the ‘Fastest’ setting does cut down on some of the trailing. Instead it replaces it with fairly strong overshoot, seen as a bright trail behind the UFO cockpit and legs and a mixture of bright and ‘dirty’ trailing behind the UFO body. None of these settings are very appealing, visually, and it would be difficult to separate them based on this. As covered in the responsiveness article, it’s important to recognise that pixel transition speeds do vary depending on the shades (grey levels) involved in the transition. Looking more broadly at a wide range of transitions, as we do in the proceeding section, it becomes apparent that the ‘Off’ setting is actually optimal. Setting ‘SmartResponse’ to anything higher does little to alleviate the most obvious ‘smeary’ trailing and simply replaces some of the trailing elsewhere with readily observable overshoot. We therefore stuck to ‘Off’ for our testing – the exception being for the video where we demonstrate all of the settings in-game.

Interlace pattern artifacts

On some monitors, including the Philips BDM4065UC, faint interlace patterns can be seen during certain transitions. These tend to be particularly noticeable where light shades (muzzle flashes, explosions etc.) briefly pop up on the screen. Rather than appearing as a solid mass, the shades appear as a woven mixture of very slightly lighter and very slightly darker variants of the intended shades. On some monitors you can see a sort of ‘moving mesh’ or grid during motion or even if you move your eyes across the screen in a certain way. These ‘dynamic interlace pattern artifacts’ were not visible on this monitor. However; we did observe some static interlace patterns, whereby some shades appeared as faint horizontal bands of a slightly lighter and slightly darker version of the intended shade. This was most predominant (but still faint) towards the bottom of the screen, becoming even fainter and eventually not visible at all higher up the screen.

Responsiveness in games and movies

On Battlefield 1 (BF1) there was a moderate degree of perceived blur attributable to eye movement and linked to the 60Hz refresh rate of the monitor. This was the main contributor to perceived blur when considering some of the transitions between particularly light shades. Unfortunately there were widespread issues with slower than optimal pixel responses, in some cases extremely sluggish transitions. This wasn’t just confined to a few transitions involving particularly dark shades or other specific shade levels but actually quite widespread. The worst offenders did involve particularly dark shades moving against somewhat brighter (‘medium’) shades, common where shadows were cast against the ground or in shaded areas of vegetation, for example. This caused an obvious smearing, something we haven’t seen to this degree on a VA model for quite some time. There was also some ‘break-up trailing’ whereby dark shades with a slight hue would appear to break-up into some brighter shades contained within. For example a dark shadow on rich red ground would appear with a smeary mixture of very dark and slightly brighter red – as if somebody had written something with dark red fountain pen ink and then smeared water across it. There was also some noticeable dark and bright overshoot trailing in places – something that became far more widespread and more obvious if any faster ‘SmartResponse’ settings were used. The video below shows a specific section of the video review where these ‘offensive transitions’ were found in full effect, on BF1.

On Dirt Rally these same sort of weaknesses were highlighted. There was again moderate blur linked to eye movement and the 60Hz refresh rate, but also considerable additional perceived blur due to weaknesses in pixel responses. On some of the brighter daytime maps, some of the more common transitions (between lighter shades) were displayed with just a bit of extra trailing and additional perceived blur. But there were often darker objects such as tree trunks, telegraph posts, shaded areas of vegetation or even darkly painted parked cars or buildings which highlighted the break-up trailing and more ‘smeary’ trailing observed on BF1. There was also some overshoot in places, for example some bright trails appearing beside trees with bright blue sky in the background. The problematic transitions became far more common when driving at night, particularly noticeable where blackened treetops silhouetted the slightly brighter skyline. Or the other way around – where objects were lit up by your car headlights with a dark and unlit environment behind them. It turned into something of a drink or drug driving simulator and wasn’t really an enjoyable experience.

There was some solace to be found when viewing ~24fps movie content such as our Blu-ray test titles. The responsiveness requirements here drop significantly, with only 24 or so discrete frames being displayed every second. With this extra breathing room, much of the more problematic pixel response behaviour (both smearing and overshoot) was kept at bay. There were some weaknesses, but nothing that really stood out as it did at higher frame rates. Perhaps the most noticeable example, but in our view still not particularly obtrusive, would be on Futurama where an afterimage of the character’s black outlines could be very briefly seen in the scene after they were shown. A similar effect could be observed on the desktop when scrolling rapidly, with black text against a black background. You can also set the monitor to 24Hz, 23Hz or 30Hz to try to match the frame rate of the content and therefore minimise juddering – the monitor runs correctly at these settings without frame skipping.

Overall we’d say that the responsiveness of the monitor is not perfect for movies, but it is certainly better suited (at least for 23 – 30fps movies) compared to higher frame rate content. It is also ‘acceptable’ for desktop use, although as this is typically running at a full 60fps you do still get smearing and other weaknesses evident even when scrolling through webpages and documents. This isn’t as detrimental to the experience as when gaming, though, where these weaknesses are not only unsightly but can at times be sickly and rather off-putting. We also found these weaknesses distracting when watching 60fps streaming content. It’s always prudent to accept some weaknesses from VA panels, but it has been a while since we’ve seen one that’s quite this poor in terms of pixel responsiveness. And that’s a bit disappointing given the motion handling of the older BDM4065UC (PWM artifacts aside).

The ‘4K’ UHD experience

A 40” screen is certainly a sight to behold when it’s sitting on your desk under a metre from your face. And it is also quite a different experience to using a smaller screen – even one that’s a ‘mere’ 27” or so as we were using beside and directly prior to this. We found it quite easy to adapt to the physical size of the screen and didn’t find it ergonomically unsound – no dodgy neck pain or anything like that. We generally viewed the screen from around 70 – 80cm and were able to glance at all content there without any head movement. If you wear glasses and you have the rims to contend with, it might necessitate some accommodation in the form of head movement as well, but nothing extreme we feel. It is difficult to say whether the curve really aided this aspect of the viewing experience. At 3000R, it’s really rather subtle and not soon after using the monitor we sort of forgot it was even there. That’s good in the sense that the image appeared rather natural and not out of place or distorted. And perhaps it did aid the viewing of content near the edges of the screen a bit – it has been a while since we’ve used a screen anywhere near this big without a curve for PC usage.

With a 3840 x 2160 (‘4K’ UHD) resolution spread across the 40” screen, the pixel density is 110.15 PPI (Pixels Per Inch). That’s very similar to the 108.79PPI of a 27” WQHD screen, and as such many users will be perfectly comfortable reading text and interacting with their programs without using scaling. As explained in this article, the often necessary evil of scaling is something that generally goes with the territory for significantly smaller UHD screens. So here, you can enjoy the full ‘real-estate’ of the 3840 x 2160 resolution and 40” screen in all its native glory. Just some examples below of the sort of workspace you have at your disposal.

The pixel density delivers a similar level of detail and clarity to a 27” WQHD when gaming as well.So you don’t get the same benefit as with higher pixel density displays (32” or smaller UHD models, for example) but certainly get a nice boost over lower pixel density displays. There is also something quite impressive about seeing this spread across such a large glossy screen. And the physical size of the screen is certainly engrossing, which is something that will be quite endearing to some gamers. The size also worked nicely for engrossing film or general TV watching, we should add. As mentioned previously the curve is subtle and we don’t really feel it delivered anything ground-breaking to the experience. We wouldn’t say it was really significant enough to add to the feeling of depth or immersion when playing games – although the screen size alone did a nice job in that respect. The images below show the monitor in action whilst gaming. These in no way represent what you actually see first-hand and are purely for illustrative purposes – they also greatly exaggerate the curve, which is barely noticeable when actually using the monitor.

Interpolation and upscaling

The 3840 x 2160 resolution is quite demanding and indeed some devices, including most games consoles, are confined to lower resolutions anyway. You can run the monitor at 1920 x 1080, whereby the monitor uses an interpolation (scaling) process to map the resolution onto its 3840 x 2160 pixels and therefore use all of the screen space. If you prefer, you can have only 1920 x 1080 pixels displayed with a large black border around the screen. This is referred to as 1:1 pixel mapping – refer to the OSD video and the ‘Picture Format’ mode which can be set to ‘1:1’. PC users need to make sure that the monitor is handling this, rather than the GPU. AMD GPUs will automatically get the monitor to handle the scaling when gaming, by default. Nvidia GPU users should open Nvidia Control Panel and navigate to ‘Display – Adjust desktop size and position’. They should then ensure that ‘No Scaling’ is selected and ‘Perform scaling on:’ is set to ‘Display’ as illustrated below.

Curiously, the monitor does not use interpolation when displaying non-native resolutions higher than 1920 x 1080. If you select 2560 x 1440, for example, 1:1 pixel mapping is always used regardless of whether you’ve selected ‘1:1’ or ‘Widescreen’ as the ‘Picture Format’. The GPU could be used to scale if you really need to use all of the pixels, but this provides a softer look than would have likely been achieved using the monitor’s interpolation process. The same occurs if the GPU is scaling 1920 x 1080. Using the monitor’s interpolation process to view 1920 x 1080, though, gives a surprisingly good experience. Some people mistakenly believe that 1:4 pixel mapping will be used on a 3840 x 2160 monitor when running it at 1920 x 1080. That is not the case on any of the models we’ve come across or received feedback for (that’s dozens of UHD models) and isn’t the case here either. There is still some softening, but it was not as pronounced as you’d usually see (and certainly superior to using GPU scaling). There was a little over-sharpening in places as well, but nothing particularly disturbing. Things actually looked surprisingly similar to a Full HD screen of similar size. We would say that this provides slightly better results than leaving the monitor at 3840 x 2160 when viewing 1920 x 1080 content as well, although that’s marginal and something avid Full HD movie fans will have to experiment with and decide for themselves.

Video review

The video below summarises some of the key points raised in this written review and shows the monitor in action. This review is designed to complement the written piece and is not nearly as comprehensive.

Conclusion

The Philips BDM4037UW is a large, glossy high resolution display that follows up from the BDM4065UC and BDM4350UC. As with the latter, this model features a flicker-free backlight – but like the former it features a VA panel. It also adds a subtle curve. Although it is difficult to give a thorough analysis of what the curve brings to the experience, given that it was some time since we used a flat monitor of this size, we did find it a nice little addition. It was certainly subtle enough to be unobtrusive and provided a natural viewing experience, but it didn’t feel as if it added much extra depth or immersiveness to the experience. Given the size of the screen, though, ‘immersion’ was not lacking in the first place. The 3840 x 2160 ‘4K’ resolution being spread across the 40” screen provided a nice practical pixel density, giving lots of real-estate without most users feeling the need to apply scaling. It also gave a nice pixel density for games, whilst not quite providing the same ‘wow factor’ as tighter pixel density screens (32” or smaller UHD models, for example).

The screen itself uses the same sort of glossy finish with extremely mild anti-glare treatment seen on its predecessors. This preserved a great amount of vibrancy and clarity and provided a ‘smooth’ and ‘pure’ look to the image. It also gave that ‘wet’ or ‘painted-on’ appearance in brighter ambient environments, whilst cutting out some of the sharp reflections associated with certain glossy surfaces. The image quality was also pleasing overall on this monitor, with strong static contrast and a generous colour gamut combining with the screen surface to deliver an image with excellent vibrancy and ‘pop’. As is usual for VA panels there was a degree of saturation lost and a bit of ‘black crush’ due to inherent viewing angle weaknesses, but nothing extreme by any means. The OSD also gave good flexibility to the user, including a range of gamma settings and even a ‘Low Blue Light’ setting (not labelled as such, but certainly having that effect).

The Achilles heel of the VA panel type is responsiveness. It does vary between models, with some faring better than others. The BDM4065UC, the VA predecessor of this model, was surprisingly good in terms of pixel responsiveness. It was let down by PWM artifacts due to the dimming method employed by the backlight and there were some weaknesses, but overall a decent performance. The BDM4037UW, unfortunately, had more pronounced weaknesses in its pixel responsiveness. Whilst some pixel transitions were performed rapidly (those involving predominantly lighter shades), where medium-dark or darker shades were found there were severe weaknesses. There was a mixture of overshoot, ‘break-up’ trailing and some of the most severe smeary trailing we’ve seen on a monitor for quite some time. This was quite bothersome at times and is sufficient to make us hesitant to recommend this model to gamers. Sensitivity to this does vary, though, and some users would find it fine for ‘light gaming’. The input lag was actually quite low, at least – and in that respect it was an improvement on both of its predecessors. The weaknesses in pixel responsiveness didn’t really come into play when watching lower frame rate movie content (23 – 30fps), which is good because such content was very enjoyable on this large, glossy high-contrast screen. Whilst these weaknesses were apparent on the desktop, we wouldn’t say they particularly impeded the experience there and they didn’t detract from the obvious benefits of the screen size and resolution.

Overall there was plenty to like about this monitor. The overall design is nice, with a good amount of powder-coated metal and a surprisingly slender screen and bezels. The screen is also lifted a bit higher off the desk compared to previous models, whilst VESA holes again feature if greater ergonomic freedom is required. With a few tweaks in the OSD the overall image quality was pleasing as well, with excellent vibrancy and strong contrast. There wasn’t any troublesome input lag and HDMI 2.0 is provided as well as DP 1.2 for added flexibility. Interpolation performance at 1920 x 1080 was also pleasing, meaning that the monitor does a good job when connected to lower resolution sources such as Blu-ray players and some games consoles. The real fly in the ointment for this monitor, then, is the pixel responsiveness. This may well be a deal-breaker for some users and depending on uses may make the monitor less than ideal. Given the obvious strengths in other areas, though, the BDM4037UW could well provide a very enjoyable and practical experience for others.

The bottom line; a monitor with many image quality strengths, but also some troublesome issues with pixel responsiveness.

 

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