Sony Alpha 6400 review

March 8, 2019

Overall Rating:


Sony Alpha A6400

  • Features:
  • Build/Handling:
  • Autofocus:
  • AWB Colour:
  • Dynamic Range:
  • Image quality:
  • LCD viewfinder:


  • + Astonishingly capable subject-tracking autofocus
  • + Excellent image quality in almost any shooting situation
  • + High level of control customisation available
  • + Relatively compact size and decent build quality


  • - Out-dated body design is much less pleasant to use than its competitors
  • - Control setup is poorly-configured out of the box
  • - 16:9 LCD screen gives small display area for 3:2 stills
  • - Minimal touchscreen functionality
  • - No in-body image stabilisation



Price as Reviewed:

£950.00 (body only)


Sony’s latest APS-C mirrorless features some remarkable technology, says Andy Westlake, but is let down by its out-dated body design.

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Sony Alpha 6400: Image quality

Sony has fitted the A6400 with the same 24.2MP APS-C sensor as its predecessor, but teamed it up with a faster processor. Unlike the firm’s current full-frame and 1-inch type sensors, it doesn’t use a back-illuminated or stacked architecture. As a result, the A6400 is now technically surpassed by Fujifilm X-T30, with its 26.1MP back-illumimated X-Trans CMOS 4 sensor. But it’s still capable of excellent image quality, with good detail and dynamic range at low sensitivities, and strong performance at higher settings up to ISO 6400.

The tilting screen is handy for low-angle shooting. Sony A6400 + E 20mm F2.8 pancake, 1/4000 sec at f/2.8, ISO 100


At ISO 100 in raw format the A6400 comes close to the maximum resolution its sensor could theoretically deliver, achieving approximately 3800 lines per picture height before false colour and maze-like aliasing creep in. This falls progressively as the sensitivity is raised, but the camera still maintains around 3000 l/ph at ISO 6400. At higher settings, noise has an increasing impact, with around 2800 l/ph resolved at ISO 25,600 and just 2000 l/ph at the top extended setting of ISO 102,400. Sony’s JPEG processing prioritises suppressing artefacts, resulting in slightly lower resolution compared to raw.

In  the crops below, multiply the numbers beneath the line to calculate the resolution in lines per picture height.

Sony A6400 resolution, raw ISO 100

Sony A6400 resolution, raw ISO 400

Sony A6400 resolution, raw ISO 1600

Sony A6400 resolution, raw ISO 6400

Sony A6400 resolution, raw ISO 25600

Sony A6400 resolution, raw ISO 102400

ISO and noise

At low sensitivities the Alpha 6400 delivers finely-detailed images with barely any hint of noise. Increase the setting to ISO 800 and noise starts to impinge on even-toned areas when viewed closely onscreen, but you’d really struggle to see it in print. This gets more pronounced at ISO 1600 and ISO 3200, but I still wouldn’t hesitate to use these settings. Indeed it’s only really at ISO 6400 that there’s clearly a negative impact on fine, low-contrast detail and colour saturation, although image files still look quite usable, especially with a touch of luminance noise reduction applied. Beyond this things go downhill fast, and while ISO 12,800 images might still be OK when viewed at smaller sizes, the top three settings all suffer from muted colour and excessive noise that swamps all but the broadest details.

Sony A6400, raw ISO 100

Sony A6400, raw ISO 400

Sony A6400, raw ISO 1600

Sony A6400, raw ISO 6400

Sony A6400, raw ISO 25600

Sony A6400, raw ISO 102400

  • Sensor: 24.2MP CMOS (23.5 x 15.6mm)
  • Output size: 6000 x 4000
  • Focal length mag: 1.5x
  • Lens mount: Sony E
  • Shutter speeds: 30 – 1/4000sec + bulb
  • Sensitivity: 100-32,000 (standard), 100-102,400 (extended)
  • Exposure modes: PASM, Scene, Auto, Panorama, Movie
  • Metering: Multi, centre-weighted, spot, average, highlight
  • Exposure comp: +/-5 EV in 0.3EV steps
  • Continuous shooting: 11 fps
  • Screen: 3in, 921,600-dot 16:9 tilting touchscreen
  • Viewfinder: 2.36m-dot, 0.7x magnification
  • AF points: 425 phase-detect, 425 contrast-detect
  • Video: 3840x2160, 30fps
  • External mic: 3.5mm stereo
  • Memory card: SD, SDHC, SDXC, Memory Stick Duo
  • Power: NP-FW50 Li-ion
  • Battery life: 360 shots per charge
  • Dimensions: 120 x 66.9 x 59.7mm
  • Weight: 403g (with battery and card)

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