There were several significant problems with this mode though initially, most obviously that it didn’t actually offer any sRGB emulation at all! The new firmware adds this feature in to the OSD menu and we are told that this delay to the feature was because of an issue with DSC (Display Stream Compression) with NVIDIA and that it has been addressed with their latest drivers, v457.

ViewSonic had added it to their XG270QG display which used the same Nano IPS panel as the 27GL850 and we had seen some issues with the blur reduction because of the backlight in that review. Depending on the scene (how demanding it is in terms of dark and bright parts), HDR content will look either notably better or not that much better than SDR. Performance at fixed refresh rates including maximum – this is important for those who have a powerful enough system to consistently output a frame rate to meet the max refresh rate capability of the screen.

If you are in hot room and want it quiet please keep this in mind, if you have good cooling in your room you should be able to avoid this. Those were criticised a bit for their lower-than-typical contrast ratio, so it was good to see that the 27GN950 didn’t suffer the same fate.

Some people may find this problematic if they are playing a lot of darker games or watching darker movies. We never felt that the overshoot became too noticeable or distracting in practice, and it’s only really at the very low end where you might start to see a few pale halos appear, but they are very slight.A slight darkening of the image occurred horizontally from wider angles as you can see above as the contrast shifted slighting. Pixel density is a measurement of a screen's resolution, expressed as the number of pixels per inch (PPI) on the screen. It provides quite a bright back lighting option behind the screen and a good range of options and modes to play with.

Most of the OSD controls are locked at the end, although brightness is left available which is good news if you want to change that for different times of the day, or to your liking. The default setup of the screen was reasonable as well, offering an accurate gamma curve and decent contrast ratio for an IPS panel. The 27GN950 obviously offers 4K resolution and some other features, whereas the 27GL850 was “only” 1440p, but the Nano IPS panels performed very similarly when it came to these other areas. It should be noted that for these tests we disabled the ‘Smart Energy Saving’ function in the OSD menu and also turned Local Dimming off. To be honest we’d have rather LG had stuck with a more traditional response time spec like 4 ms G2G and delivered a great performance in that range, than push unrealistic and unachievable marketing figures that don’t live up to the hype.In the “TV” section of the graphics card settings (labelled “Ultra HD, HD and SD”) we saw options only for 4K and 1080p. We have deliberately not included luminance in this comparison since this is normally far too high by default on every screen.

cd/m 2 at this default brightness setting, giving us a decent 979:1 contrast ratio for an IPS panel and close to the spec. They gave us access to this new firmware early for additional testing and we are pleased to report it did indeed fix the problem with the emulation nicely. Response time performance should be pretty consistent across the refresh rate range anyway, so the above also applies really at 144Hz, or near enough.The screen supports VESA Adaptive-sync and so can support variable refresh rates from both AMD FreeSync and NVIDIA G-sync systems. The wide viewing angles provided by this panel technology on both horizontal and vertical planes, helps minimize on-screen colour shift when viewed from different angles.