The LG G Flex may have a giant screen that is one of the most notable we’ve seen in a while, but that doesn’t mean it is any good in terms of pure image quality. It has significant issues.

It is unable to properly display block colours, and is riddled with what looks like moire noise throughout the entire display. It’s weirdly mottled unless it’s displaying pure black. You can trick yourself it’s a deliberate effect of the G Flex’s background and icons until you head somewhere like the web browser, where the unsightly texture of the phone’s screen is undeniable.

The only way to minimise the effect is to turn brightness up to maximum. Of course, that will also minimise battery life so isn’t much of a solution.

The G Flex also has serious issues with image retention. High-contrast objects like the clock or any particularly bold app icons are visible for 20 seconds or so after they should have left, in the form of ghostly afterimages. And, once again the effect is much worse when brightness is set to the lower levels most of us use, rather than max.

It’s been so long that we’ve seen such basic screen issues in a mobile device that we at first thought they were some sort of ill-advised software feature. But they are not.

These problems are the sorts of gremlins you get when working with a fairly young screen technology. P-OLED’s problems will be ironed out in time, but it’s already too late for the LG G Flex.

Colour reproduction is reasonable at top brightness, but colour fidelity is decimated as soon as you turn the brightness down a bit thanks to the screen texturing issue.

As you’d hope from an OLED screen, contrast and black level are both very strong. You don’t get the residual luminance of an LCD screen’s backlight here, so in a darkened room blacks remain super-black. The G Flex’s screen bezel is slightly silvery too, making the display actually look blacker than the surround.

There is yet another issue with the screen, though – resolution. The G Flex has a 720p resolution display, which is not much to work with across a 6-inch screen. Pixel density is 245ppi. And it’s not enough to make text look super-sharp.

Turn up the brightness to get rid of the screen texturing issue and sharpness is reasonable, but not for a £500 phone. Clarity is much worse than many cheaper rivals, including LG’s own LG G2, which has an excellent display in comparison. We can once again blame that P-OLED is still in its early stages, but that isn’t something the phone buyer should have to put up with.