Sony KD-55XF9005 (XF90/ X900F) Review
Type: FALD LED LCDResolution: 4K

Sony XF90/ X900F Review


By Vincent Teoh
Published: 1 May 2018

Overall

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The 55-inch Sony KD-55XF9005 is a good-looking TV with a sleek design, but its "duck feet" stand will divide opinions. If you are struggling to fit the television on your AV rack, you can also reverse the positions of the feet so they point inwards and require less footprint, although this method of installation is not explicitly stated in the user manual.

Build quality is as expected for a midrange set. Power cable is affixed to the chassis.

Bezel

The bezel is surprisingly thin, belying the underlying full-array local dimming (FALD) direct-lit LED backlighting. There's a BRAVIA inscription on the top left corner, and a Sony logo at the bottom.

Connections

Four HDMI inputs are provided (not shown). However, only HDMI2 and HDMI3 are the full-bandwidth ports that can support [email protected]/60 at higher bit depth or chroma... you'll need to use these for Apple TV 4K box (with Dolby Vision), Sky Q, PS4 Pro and Xbox One X consoles, and remember to change [HDMI signal format] to "Enhanced format". You can still connect your 4K Blu-ray player (most Ultra HD Blu-rays run at 2160p24) to either HDMI1 or HDMI4.

Remote Control

Slight improvement over Sony's remote controls over last few years, with discrete buttons. Still lacks the premium feel.

LCD Panel Type

True RGB VA-type LCD panel which delivers deep blacks by LED LCD standards. Native ANSI blacks was 0.05 cd/m2 if peak white was set at 120 cd/m2.

LED Backlight

Direct-lit LED backlighting. 

Local Dimming

6 vertical columns x 8 horizontal rows = 48 independently dimmable zones

Colour Checker

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After calibration, none of the 140 measured colour patches exhibited inaccuracy that exceeded the humanly perceptible threshold of delta error (dE) 3, which is remarkable considering there's no advanced colour management system (CMS) on the Sony XF90. Memory colours such as skin tones and foliage will look very realistic and natural in all types of SDR content.

Spectral Power of Distribution

The Sony 55XF90 uses PFS phosphor in the LED backlight.

Clarity

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The Bravia XF90 or X900F carries the Japanese manufacturer's novel X-Motion Clarity technology which combines the light-boosting potential of the FALD system and backlight blinking to achieve high motion resolution without incurring significant increase in flicker or decrease in brightness.

The X-Motion Clarity system is activated when [Motionflow] is set to "Smooth", "Standard" or "Custom" with [Clearness] at "1". To curb the amount of soap opera effect (SOE) introduced to 24fps films, it's best to optimise the [Motionflow] "Custom" settings.

Smoothness

Handles 24p video signal natively without any sign of telecinic judder. Unlike last year's XE90, the Sony XF9005 does not suffer from frame repeat problems with 50Hz content.

Upscaling

The onboard X1 Extreme chipset delivers the best in-TV upscaling we've seen from consumer-grade televisions, presenting crisp detail with minimal ringing even from standard-definition material.

Deinterlacing

  • Video-mode deinterlacing: Good jaggies reduction
  • Film-mode deinterlacing: Passes 3:2 cadence in 480i & 1080i; 2:2 in 576i with [Film mode] engaged. Loses lock with 2:2 in 1080i.

Gradation

The [Smooth Gradation] Super Bit-Mapping feature on the Sony KD-55XF9005 works effectively to smooth out in-source posterisation.

Screen Uniformity

No vertical or horizontal bands. Minimal DSE (dirty screen effect), although corners are slightly darker, which is common on Sony LED LCDs.

Viewing Angle

Colours and contrast deteriorate off-axis due to the VA-type LCD panel used.

Peak Brightness

  • 10% window: 1000 nits
  • Full-field: 685 nits

The combo of full-array local dimming (FALD) and high peak brightness results in an impactful HDR presentation.

Colour Gamut Coverage

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PQ EOTF Tracking

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Like all Sony HDR TVs, the Bravia KD55XF9005 ignores static metadata found in HDR content. The company's display mapping algorithm favours maintaining APL (Average Picture Level) at the expense of sacrificing some bright specular highlight detail.

1080p SDR

Input lag is higher by one frame in 1080p SDR because of the upscaling needed, which won't please Nintendo Switch owners.

4K HDR

HDR games from PS4 Pro and Xbox One X feel responsive and look impactful with sufficient brightness.

Pros

  • Superb motion sharpness thanks to X-Motion Clarity
  • Class-leading upscaling quality
  • Impactful HDR picture
  • Highly accurate colours after calibration
  • Deep blacks by LED LCD standards

Cons

  • Narrow viewing angle because of VA LCD panel
  • 1080p input lag higher by 1 frame
  • Clunky Android Smart TV system
  • Only two full-bandwidth (18Gbps) HDMI ports
  • Controversial feet design

Verdict

A versatile midrange LED LCD TV that excels particularly with motion clarity, upconversion quality and HDR impact. We don't think you can find another 2018 model 55in TV with better picture quality under the £2000 mark (at this time of writing in April 2018).