ViewSonic VP2780-4K

Responsiveness

Input lag

A sensitive camera utility called SMTT 2.0 was used to assess the ViewSonic VP2780-4K’s latency. This monitor was photographically compared with a range of other monitors where the latency values are known whilst running this test on the same system. Using this method we calculated 10.5ms (over ½ a frame) of input lag. This value is influenced both by the raw signal delay (the element you ‘feel’) and pixel responsiveness (the element you ‘see’) and indicates that the monitor has quite a low signal delay that shouldn’t prove problematic to most users. The overall ‘feel’ of the monitor was influenced primarily by its 60Hz refresh rate.

Perceived blur (pursuit photography)

In this article we explore the limitations of the traditional static photography methods used to capture the motion performance of a monitor. We introduce the concept of ‘pursuit photography’, which uses a moving camera to capture movement on a screen in a way that accurately reflects what the eye actually sees. This is something that static photography and videos simply don’t represent correctly. The images below are pursuit shows captured with the UFO Motion Test for ghosting running at 960 pixels per second. This is a good practical speed for such photography and allows accurate analysis of both blur from eye movement and pixel response behaviour. The monitor was set to its three different ‘Response Time’ settings; ‘Standard’, ‘Advanced’ and ‘Ultra Fast’, respectively. The bottom photograph shows a fast 60Hz reference – a Samsung S27A750D set to full brightness (to eliminate PWM) and 60Hz, using the ‘Faster’ response time setting. The pixel responses on this model are fast enough so that the transitions here are masked entirely by perceived blur – and there is no observable overshoot (inverse ghosting) either.

Perceived blur with various settings

With the ‘Standard’ setting you can see a fair bit of ‘blur’ behind the UFO (remember that it travels from left to right) on top of what is observed due to eye movement. The bottom image, the fast 60Hz reference, shows what you would observe due to eye movement alone. This ‘blur’ is therefore trailing, which is visible here due to sluggish pixel response times for the transitions being shown. With the ‘Advanced’ setting this trailing is cut down significantly, although there is still a little bit remaining as you can see by comparing to the reference. The ‘Ultra Fast’ setting produces what looks like a shadow behind the UFO – that is overshoot (inverse ghosting) due to overly aggressive pixel overdrive.

From this analysis it is clear that the ‘Advanced’ setting is optimal for this monitor. For these transitions things actually come quite close to the 60Hz reference, with the pixel responses only playing a minor role in the overall perceived blur. It is important to remember that different transitions (i.e. movement involving different shades) can occur at different speeds. In the analysis that follows we take a subjective look at the gaming experience, considering perceived blur over a very broad range of different pixel transitions and in various different scenarios.

Responsiveness in games and movies

On Battlefield 4 the motion blur was largely as you’d see on even the fastest 60Hz LCDs. There was some slight trailing on top of this, but as demonstrated in the previous section this was quite minor. It was most noticeable when moving rapidly and a vehicle with a mixture of light and darker shades, for example earth and vegetation with some lightly painted buildings in the scene. Even then the perceived blur was largely down to eye movement with only a weak influence of pixel responsiveness. We did observe some light traces of overshoot (inverse ghosting) between some medium shades. For example if you moved past silver metal pylons with blue sky in the background, it produced a slight trail that was a little darker than the sky (and of course the pylon). If you moved past a dark object (such as a rotor blade or darkly painted vehicle) with the same blue sky in the background it produced a lighter trail than either of these shades, an almost transparent-looking trail. In both cases this was rather faint and not something some users would notice even if they were specifically looking out for it. We don’t feel it’s the sort of overshoot that would prove distracting if playing the game normally, even to sensitive users. It didn’t occur at all for the majority of transitions, either, only in specific scenarios such as those described.

There was a moderate degree of blur on Dirt 3, intensifying during sharp cornering and other rapid manoeuvres. This was again largely as you would see on the fastest 60Hz LCDs, with pixel responsiveness only playing a minor role. Even on the Gymkhana mode we don’t feel this slight whiff of extra trailing here and there would actually impede anybody’s playability of the game. If a user is sensitive enough to find this problematic, then they aren’t likely going to be satisfied with any 60Hz LCD. As on Battlefield 4 there was no obvious overshoot, just slight traces here and there which were not distracting.

We also tested the Blu-ray movie titles mentioned earlier. These titles run at a framerate of around 24fps, which is really the limiting factor when it came to fluidity. Here the pixel responsiveness did not impede the experience at all, nor was there any observable overshoot.

The ‘4K’ UHD experience

In this article we explore the experience of using the ‘4K’ UHD resolution of 3840 x 2160 on a 28” screen. Because this is a 27” screen with the same resolution, the pixel density and hence overall experience is extremely similar. We are therefore not going to repeat too much of what was said on that article but rather supplement it with some additional testing. Although we did find the monitor ‘useable’ on the desktop with no scaling applied, the text and other elements in programs such as buttons are really rather tiny. Depending on eyesight and preferences various degrees of scaling would be used instead, with ‘Medium – 125%’ being quite agreeable with ourselves on Windows 8.1. To give a vague idea of the sort of increase this makes to the relative size of things please observe the images below. The top one shows the desktop with no scaling (‘Small – 100%’) whilst the second image shows ‘Medium – 125%’.

We won’t repeat what we’ve already said about how hit and miss scaling can be depending on the programs used, but the more general programs we used (web browsers, the latest Microsoft Office suite etc.) worked nicely. They have an independent zoom control allowing text size to be altered according to preferences independently of the scaling set in Windows. The image below shows how nice this monitor can be for multitasking, with a Microsoft Word document on the left side of the screen and Google Chrome open on the right side. Text was small but crisp and perfectly readable for us – so plenty of content could be displayed at any one time, which is good for productivity.

To supplement our article we would like to look at what the ‘4K’ UHD resolution brought to the table on a couple of other game titles. First up we played through some of the Battlefield Hardline campaign. The screenshots in this section will not give you a good idea of what the game actually looks like first-hand on the monitor, as that is not possible, but are simply there to help set the scene. Some textures showed excellent levels of detail and a look that only a pixel density this high could give. The dimpled orange plastic of tactical equipment boxes, realistic-looking pond weed in the Everglades (an important visual feature, of course), rusty old barrels and graffiti on weathered walls all took advantage of the resolution. As observed in our experience article, the need for Multi Sample Anti-Aliasing (MSAA) or similar is also greatly reduced. It certainly isn’t the case that aliasing magically disappears completely without AA enabled – thin straight edges in particular still have some little jaggies on them. But the prevalence of these jaggies is hugely reduced such that most of the game environment looks ‘jaggie-free’ even without the use of MSAA. The clarity of the game world as you stare into the distance was also excellent.

We also had a play on Grand Theft Auto 5 (GTA V). There were again some textures that don’t really take advantage of the high pixel density of the ViewSonic. The character’s clothes, for example, have quite flat and undetailed-looking textures. On this title, though, there were an abundance of textures that really did take advantage of the high pixel density, at least if your character’s face wasn’t right up against the texture. Road textures were particularly impressive, as was a lot of the vegetation in the game which generally had an excellent crisp and detailed look. Painted breeze block walls and some signs on those walls had a very realistic quality to them, is did reflections on shiny floor surfaces or wet roads. Skin textures (wrinkles, dimples, stubble, pores and all) also had a good believable quality to them. Reflections on cars and shiny floor surfaces also looked uniquely appealing. And last but certainly not least, the vehicles themselves looked appealing at this resolution. Carbon fibre and leather elements, alloy wheels, tires and whatnot all looked pretty impressive – as did the paintwork in general, especially once it developed imperfections.

Interpolation and upscaling

The native resolution of the monitor is 3840 x 2160, also referred to as UHD (Ultra High Definition) ‘4K’. This is an awful lot of pixels for your computer to work with, putting particular strain on the GPU when gaming. You may also connect some devices, such as games consoles, which simply won’t run at that resolution and instead might be limited to 1920 x 1080 at most. The following section of the OSD video, shown previously, looks specifically at the scaling options available on the monitor. These are found in ‘Manual Image Adjust – Aspect Ratio’ within the OSD. The two key options here are ‘1:1’ and ‘Full Screen’. 1:1 is a pixel mapping setting which specifies that only the pixels used in the selected (or source) resolution are actually used, with a black border being used for the remaining pixels. The second option ensures that all of the 3840 x 2160 pixels of the monitor are used regardless of the resolution selected, with the monitor using an interpolation process to ‘fill out’ the image in this way.

When the monitor uses its interpolation process, its handling of non-native resolutions is actually quite reasonable. You do lose a bit of sharpness compared to running a given resolution natively on a screen of similar size and screen surface, but the softening is not as severe as we’ve seen on some models (including UHD ones). We specifically tested 1920 x 1080 and 2560 x 1440 and found that both were handled similarly in terms of interpolation – just because 1920 x 1080 divides into 3840 x 2160 nice and evenly does not mean that ‘perfect scaling’ is used. Exactly the same interpolation process that is used to display 2560 x 1440 on this monitor is employed. You could definitely see that text or textures and edges in games lacked the sharpness of a 27” monitor running that resolution natively, but it didn’t look like you were looking at everything through a soft-focus lens.

As the video shows, you can also run the monitor at 4096 x 2160, which is the DCI (Digital Cinema Initiatives) 4K standard or as some people might refer to it ‘true 4K’. This is primarily for compatibility purposes or content creation in this resolution. The monitor can’t magically generate extra pixels or change its aspect ratio to suit, so things look a bit squashed horizontally as an interpolation process is used. The overall clarity is still quite good though, so this is certainly useable if you need it. The screenshot below shows how this resolution is presented in the resolution list on Windows.

Conclusion

The range of ‘4K’ UHD models available on the market is increasing at quite a pace, with several ‘affordable’ options available with various panel types and sizes. The ViewSonic VP2780-4K is designed to offer strong colour performance at a competitive price. Its IPS panel was put to good use with a strong factory calibration. The factory calibration didn’t quite hit the ‘6500K white point’ and ‘2.2 gamma’ targets, but it came close enough for any differences to be counteracted by lighting conditions anyway. Of course, if particular targets are imperative for your workflow, then you should be performing your own calibration appropriate to your own system, unit and lighting conditions at any moment in time. For general use (including gaming, web browsing and watching movies) the exceptional variety and richness of colours was very pleasing, with excellent consistent representation of shades within the sRGB colour space.

The 3840 x 2160 resolution was also appealing in both the real-estate that it provided on the desktop and the level of detail it brought to games. There is certainly room for improvement as far as its handling on some applications goes, but that is not a fault of this monitor specifically. We were also pleased with the handling of non-native resolutions such as 1920 x 1080 (Full HD) and 2560 x 1440 (WQHD) on the monitor, with quite a good interpolation algorithm being used. There was also the rather nifty inclusion of the 4096 x 2160 (‘True 4K’ or DCI 4K) resolution. This was handled of course using interpolation rather than the monitor suddenly gaining extra pixels, but is a compatibility feature some content creators would admire.

Elsewhere performance was pleasing on the whole. Static contrast was about as strong as you can expect from a panel of this type, although the usual loss of detail in some sections of the screen due to ‘IPS glow’ persisted. Responsiveness was also quite strong overall, within the constraints of the 60Hz refresh rate. Input lag was much lower than we’ve seen on some UHD models (and even most WQHD models for that matter) whilst the pixel responses only played quite a minor role in perceived blur on the screen. The pixel overdrive solution was well balanced using the ‘Advanced’ setting, without obvious overshoot or bothersome trailing.

The VP2780’s styling didn’t exactly get the heart racing, as this was certainly designed to be a sensible-looking monitor that is functional rather than flashy. Ergonomic flexibility was strong with full adjustability, although we were not fans of the excessively deep stand as it brought the screen closer to the eyes than we would have liked. Fortunately VESA mounting to a stand or mount of your choice is an option if that does happen to bug you. The range of ports was good – this included HDMI 2.0, DP 1.2a, HDMI 1.4 with MHL 2.0 support and USB 3.0. Overall this monitor provided a strong all-round performance. It is not perfect, like every model out there, but it should make your shortlist if you’re interested in a UHD model of this size.

 

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