BenQ EW2750ZL

Colour in games and movies

Colour reproduction was excellent overall on BF4. The environments looked natural and as they should, with rich and well-represented colours on the whole. There was a pleasing palette of rich greens and earthy browns, with just a bit of weakening saturation towards the very side edges and bottom edge of the screen. Richness was maintained for a given shade much better than you’d typically see on a VA panel of this size, aiding the apparent variety of unique shades. There were some very impressive vibrant dashes of colour here and there too, most noticeable where bright shades are set against a darker background. Rich orange flames and sparks in dark areas were particularly spectacular, as were the neon green and red painted ‘ghost sights’ of certain weapons.

Colours were equally pleasing on Dirt 3. There were lashings of vibrant colours for the car liveries and advertising around the track, which is exactly the aesthetic that such elements crave. Some of the liveries showed off some impressively deep reds and blues as well as some neon shades with excellent ‘pop’ – especially where black was mixed into the palette for contrast. The environments looked appropriately rich and natural, with a very nice variety of plant-like greens and neutral browns. There were some impressively lush greens in the mix, with just a bit of saturation loss peripherally as noted earlier.

The colour reproduction was also strong on ESO. There were some strong and vibrant blue, purple and red spell effects – popping with real brilliance in dark surroundings in particular. The neon yellowish-green glow of ‘torchbugs’ and cyan and purple flames throughout the game were really eye-catching. The environments showcased a good range of earthy browns and green tones, giving a pleasing and varied look. There was some saturation lost as as observed in other titles, towards the edges and bottom of the screen. This was really as subtle as we’ve seen on a 27” VA panel, however.

On the Skyfall Blu-ray colours were represented in an appropriate way. Skin tones appeared appropriately saturated, as did natural environments. The weakening saturation towards the sides of the screen was too subtle to detract from the rich look overall. There were also some impressive moments of vibrancy as well, for example the bright cyan and blue neon lights in the Shanghai night scenes. There was also a rather striking red dress worn by Miss Moneypenny which stood out very well without looking overblown or incorrect.

We also assessed colour reproduction using the Blu-ray of Futurama: Into the Wild Green Yonder. Right from the start of the film it was clear that the monitor provided just the aesthetic that this title craves. The opening scenes show various ‘neon’ shades such as brightly coloured glowing violet planets and green cosmic energy. These elements stood out with brilliant vibrancy against the deep, dark space surrounding them. Throughout the film there were plenty of other elements like this, alongside other deep shades and bright neon shades that were represented with pleasing pizazz. The movie also calls for varied production of closely matching pastel shades, with many objects and skin tones showing only very slight variation with their neighbours. In this respect the monitor did quite well, particularly for a non IPS-type panel. The weakening saturation peripherally and viewing angle-related shifts in gamma meant that shades didn’t maintain the same consistency and individuality as on IPS-type panels. But variation here was not extreme, certainly much less extensive than TN panels of this size and what you’d typically see on a VA panel. Compared to earlier AMVA+ panels, such as the ones used on the EW2740L, it’s quite possible the shifts in colour are even less extensive. But without the aid of a side-by-side comparison and owing to the fact we tested the former model a long time ago it would be difficult to say for sure.

Viewing angles

We used Lagom’s tests for viewing angle to aid our exploration of colour consistency and viewing angle performance. The following observations were made from a normal viewing position around 70cm from the screen.

The video below shows this text test, a mixed desktop background and dark desktop background from a range of viewing angles. Note the aforementioned ‘VA glow’ in the final third of the video.

Responsiveness

Input lag

A small tool called SMTT 2.0 was used alongside a sensitive camera to compare the latency of the EW2750ZL with a range of monitors of known input lag. By taking over 30 repeat readings using this method we were able to get a representative value of input lag, measuring 5.63ms (around 1/3 of a frame) of input lag. This value not only reflects the signal delay (what you ‘feel’) but also an element of pixel responsiveness (what you see). This indicates that the monitor has a very low signal delay, one which shouldn’t in itself inhibit the gaming experience.

Perceived blur (pursuit photography)

When considering the visual responsiveness of a monitor, it’s important to look at how the pixels behave during transitions between different shades. It is also important to consider how we perceive motion on the monitor. In this article we explore the concept of perceived blur and how the movement of our eyes as we track motion on the screen creates blur. This exists regardless of what the monitors pixels are doing. That article also introduces the concept of ‘pursuit photography’, whereby a moving camera is used to capture moving images on a monitor. This not only captures what the pixels of the monitor are doing but also reflects how our eye movement (or movement of the camera in this case) induces additional blur.

The images below are pursuit photographs taken using the UFO Motion Test for ghosting. The test runs at 960 pixels per second, which is a good speed for taking the photographs and for highlighting the pixel response behaviour and other blur contributors. Images are included for both the top row of the test (dark cyan background, left column of the image) and the middle row (medium cyan background, right column of the image). All of the AMA (Advanced Motion Acceleration) pixel overdrive settings on the monitor were tested; ‘Off’, ‘High’ and premium. We have also included shots taken with the monitor running at 75Hz (we will come onto this later) using the ‘High’ AMA setting. Finally we have included an image from a Samsung S27A750D set to full brightness (eliminates PWM) and 60Hz, using its ‘Faster’ response time setting. This is used as a reference to show how a 60Hz LCD should look when the pixel responses are pretty much optimal for the refresh rate.

With ‘AMA = Off’ you can see a moderate degree of trailing in addition to the blur you’d perceive with ‘perfect’ pixel responsiveness (i.e. the reference screen). This is particularly prevalent on the dark cyan background, which is something you’ll commonly observe on a VA panel due to such transitions tending to be slower. With ‘AMA = High’ performance on the dark background remained similar, with some relatively sluggish pixel transitions still occurring. The trailing was significant reduced on the medium cyan background, however. With ‘AMA = Premium’ there was actually a surprising reduction in trailing for the dark background. Unfortunately there was fairly noticeable overshoot (inverse ghosting) introduced with the transitions against the medium cyan background. In practice there was significant overshoot using this setting over a broad range of transitions, with obvious bright halo trails and things just looking overly sharp and frankly wrong during motion. Needless to say that we preferred to stick with ‘AMA = High’.

With this in mind as the optimal setting, we also tested the monitor at 75Hz. This reduced perceived blur, which you can see as the object (UFO) is slightly less elongated than any of the 60Hz examples (including the reference). This is best illustrated on the alien and his cockpit area. However; increasing refresh rate does not speed up pixel transitions. There is still considerable trailing due to slower than optimal pixel responses with the dark cyan background and a touch with the medium cyan background. We would really have liked it if BenQ could have provided a bit more acceleration for the dark background type transitions as they managed to do with the ‘Premium’ setting without noticeable negative consequences. But without accelerating other transitions such that obvious overshoot was induced.

Running a custom resolution (overclocking)

The monitor will comfortably run at up to 75Hz at 1920 x 1080. By ‘comfortably’ we mean that default timings could be used. Furthermore there were no recordable or observable changes to image quality (gamma, colour temperature or contrast) and no frame skipping – so it is ‘true 75Hz’. The monitor could be pushed as high as 77Hz with default timings, but any higher and an ‘out of range’ error was displayed along with a blank screen. In order to run the monitor at 1920 x 1080 @ 75Hz you must create a ‘custom resolution’. There is no need to adjust timings, so it’s a fairly straightforward process. The video below runs through how this can be done using the Nvidia Control Panel, or for AMD users, using a tool called CRU (Custom Resolution Utility).

We consider this to be a ‘mild’ overclock, handled comfortably by the monitor with minimal risk involved. It is likely that the monitor will last its useful lifetime at 75Hz much as it would at 60Hz. Regardless of this, 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. Please note as well that newer revisions of the monitor than the one we tested may not overclock as well (or may even overclock slightly better). This was the case with earlier models such as the GW2760HS where several revisions involving different panels were deployed over its lifetime, with differing overclockability. For the sake of this review, including the section that follows, the monitor was run at its native 60Hz refresh rate.

Responsiveness in games and movies

BF4 helped to reinforce the observations made during the pursuit photography testing. Where lighter or medium shades were involved in the transition (the majority of transitions on this title), things were largely in-line with the fastest 60Hz LCDs when it came to perceived blur. There was a little bit of extra trailing in places during some transitions, but it was really eye movement that was the predominant source of blur here. Where darker shades were added to the mix, though, some more sluggish pixel transitions came into play. Generally this would create a sort of mask of additional blur rather than creating the sort of painfully obvious smeary ‘smoke-like’ trails associated with some slower VA panels. When moving through shaded forest areas with patches of dark and lighter vegetation and ground, for example, things just didn’t quite look as sharp as they could on a 60Hz LCD. This is something that some users wouldn’t notice, whereas it may contribute to a bit of motion sickness in others (for example if zipping around in a vehicle where this ‘blur mask’ can become a bit more pronounced).

Where the very darkest shades were involved there were some slightly more extended trails similar to those captured in the pursuit photographs. If you observed dark vehicle wheels against a lighter background, for example, the dark wheel texture appeared to sort of bleed into the background a bit. You could see hints of other colours such as dark red and blue, which is typical of a VA panel. On this model it wasn’t all that extensive really and it was more that the dark texture became fuzzy with a short additional trail during faster movement. The good news is that there was very little in the way of overshoot, with just the slightest hints where some medium and light shades moved against one another. In this respect there was a vast reduction compared to the EW2740L, with as good as no overshoot this time around.

Dirt 3 told a similar story. Your average race track on this game calls for a large spread of different pixel transitions to be performed. There are plenty of light, medium and dark shades inter-twined. There are always a lot of deep shadows and areas of darker vegetation on this game with lighter shades surrounding them. Again, most of the motion blur was caused by eye movement but there was some additional blur on top of this in places. Racing at night introduced a lot of very dark shades set alongside a range of slightly lighter to much lighter shades. This introduced the slowest pixel transitions that the monitor performs. With that there was noticeable additional trailing (general additional blur) on top of what you’d expect to see from an ideal 60Hz sample and hold display. Things stopped short of those ‘smoke-like’ smeary trails that some VA models display, though, and there was no noticeable overshoot across any transition range on this title.

We also observed the Blu-ray movie test titles. The pixel responses were fast enough to handle this pace of action without introducing any issues (overshoot or response-related trailing). The fluidity of action here is limited by the frame rate at which the films run, around 24fps, and as such the demands from the monitor are lower from a pixel response perspective.

Conclusion

Having used a number of monitors with AMVA+ panels, we knew roughly what to expect from the BenQ EW2750ZL. This model is something of a refresh of the highly capable EW2740L, with slimmer bezels and some additional features in the OSD. Upon closer inspection (i.e. testing) it also became apparent that a brand new panel is used, which always piques the interest of monitor reviewers and enthusiasts alike. This delivered a similar contrast performance to its predecessor, with the specified 3000:1 seeming a little pessimistic if anything. Blacks and dark shades were impressively deep, whilst bright shades were bright and brilliant – standing out very nicely indeed against darker surroundings. The same very light matte screen surface was used, giving an impressively smooth appearance to the image and maintaining strong vibrancy. The out of the box colour setup was also pleasing, with just a few little tweaks made to improve things further. Colour reproduction was amongst the best we’ve seen from any VA panel with full sRGB colour gamut coverage and a rich and varied look to the image. As usual for a VA panel there was a degree of viewing angle dependency to the gamma curve of the monitor and there was some loss of saturation towards the far edges and bottom of the screen. This was impressively muted for a panel of this type and size, though, and seemed slightly improved even from earlier AMVA+ panels such as that used in the EW2740L.

Another area much improved from older VA panels and even some modern VA panels from other manufacturers was responsiveness. We’ve been a bit spoilt recently by testing models like the Samsung S34E790C which seemed to outperform its IPS counterpart when it came to responsiveness, but had a few more realistic benchmarks in mind for this monitor. The ‘original’ AMVA+ model from BenQ was the GW2760HS, which offered low levels of grey to grey acceleration to maintain an overshoot (inverse ghosting) free image at the expense of frequent and rather obvious trailing. Then came the EW2740L with greater levels of acceleration, cutting down on much of the trailing but bringing with it a fair degree of overshoot. The EW2750ZL sat some way between these really, offering greater acceleration than the GW2760HS without the overshoot issues of the EW2740L. Interestingly it seemed some of the more sluggish transitions (involving dark shades) were accelerated nicely by the ‘Premium’ AMA setting, but unfortunately the remaining transitions were completely overdone and burdened by excessive overshoot. The ‘High’ setting was therefore optimal, although we can’t help feeling that a little bit more fine-tuning could have been done by BenQ to improve the speed of some of the slowest transitions.

Overall this monitor delivered a very well-rounded performance. It’s a monitor that is well suited to tasks such as movie watching, general desktop work and a bit of gaming on either a PC or a console. We also feel it is suitable for a bit of hobbyist photo editing, although those serious about colour accuracy should really turn to IPS-type panels for the highest levels of consistency and lowest levels of viewing angle dependency. Some users may not be enamoured with the lack of ports, the ergonomically inflexible stand or lack of VESA holes. But we found the overall styling and minimalistic nature of the monitor quite appealing and feel its current asking price is fair.

 

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