Can Somebody Explain This Please - Its A TV Review?

Question

Contrast is fair, but is undermined by a backlight that manifests itself as an all-too-visible 'X' when the action gets properly gloomy.

Answer 1

I am guessing this is a review for an LCD TV. All LCD screens are backlit, as they have no natural light source of their own, the review says that this backlight is visible in the shape of an X in the background of the picture when the shot is dark/gloomy. Most LCD screens have poor contrast, the one being reviewed has fair/average contrast.

Answer 2

It means the contrast Is fair

The black light is how dark the color of black is.

And good with action and fast movements.