Image Quality

All of the sample images in this review were taken using the 24.2 megapixel Fine JPEG setting, which gives an average image size of around 7Mb.

The Sony A6400’s 24.2 megapixel sensor is identical to that of the older A6300 model, so image quality on both cameras is practically the same.

The A6400 generates impressively clean results with minimal grain and detail loss. At ISO 6400 there’s only a slight increase in noise and reduction in detail, making this sensitivity completely usable. Only at ISO 12800 does grain and detail smoothing become more severe, although it’s by no means unsightly. ISO 25600 is really the ceiling for acceptable image quality, such is the high level of grain, loss of detail and reduced dynamic range. ISOs 51200 and 102400 are best avoided due to the intrusive grain and colour speckling.

If you dial things down to more sensible sensitivities, though, the A6400 records excellent dynamic range, especially when assisted by Sony’s Dynamic Range Optimisation. Good colour vibrancy adds extra visual appeal while maintaining accurate colour reproduction, though this of course can be adjusted to your own preference in the camera settings.

It’s worth noting that the A6400 doesn’t incorporate sensor-shift stabilisation and instead relies on conventional lens-based optical stabilisation. But even if you don’t have an optically-stabilised lens fitted, upping the camera’s sensor sensitivity to compensate for camera shake isn’t a big deal thanks to the A6400’s respectable high ISO image quality.

Noise

The Sony A6400 has a standard sensitivity range of ISO 100 to 51200, expandable to ISO 102400. Auto ISO operates within an ISO 100-6400 range and has selectable upper and lower limits. Two levels of high ISO noise reduction can be selected – Normal, or Low – or the processing can be disabled.

JPEG	RAW
ISO 100 (100% Crop)	ISO 100 (100% Crop)
ISO 200 (100% Crop)	ISO 200 (100% Crop)
ISO 400 (100% Crop)	ISO 400 (100% Crop)
ISO 800 (100% Crop)	ISO 800 (100% Crop)
ISO 1600 (100% Crop)	ISO 1600 (100% Crop)
ISO 3200 (100% Crop)	ISO 3200 (100% Crop)
ISO 6400 (100% Crop)	ISO 6400 (100% Crop)
ISO 12800 (100% Crop)	ISO 12800 (100% Crop)
ISO 25600 (100% Crop)	ISO 25600 (100% Crop)
ISO 51200 (100% Crop)	ISO 51200 (100% Crop)
ISO 102400 (100% Crop)	ISO 102400 (100% Crop)

File Quality

Five quality settings are available: RAW, RAW+JPEG (Extra fine, Fine and Standard JPEG compression options), JPEG Extra fine, JPEG Fine and JPEG Standard. RAW files average around 24MB each, Extra Fine JPEGs roughly 15MB, Fine JPEGs are in the region of 7.5MB, and Standard quality JPEGs weigh in at approximately 5MB each.

24M Extra Fine (15.5Mb) (100% Crop)	24M Fine (7.65Mb) (100% Crop)
24M Standard (5.25Mb) (100% Crop)	24M RAW (23.9Mb) (100% Crop)

Flash

Five flash settings are available: Autoflash, Fill-flash, Slow Sync and Rear Sync, Wireless, and High speed synchronization (although this mode can only be used when an external flashgun is fitted).

With the 18-135mm lens fitted, the pop-up flash produced noticeable vignetting with the lens set to maximum wide angle when shooting a white surface from a distance of 1.5m. The flash is also too short when extended to prevent it casting an obvious lens shadow, making an external flashgun essential when shooting with wide or ultrawide lenses.

Flash Off - Wide Angle

Flash On - Wide Angle

Flash Off - Telephoto

Flash On - Telephoto

And here are a couple of portrait shots. A separate menu option controls whether or not red-eye reduction is active, but even without this enabled, the A6400 successfully avoided red-eye in our testing.

Flash Off

Flash On

Red-eye reduction

Night

This night scene was captured at f/8, ISO 100, with a 30-second exposure. The result is perfectly exposed with good detail and little image noise.

Night

Creative Styles

The Sony A6400 offers 13 Creative Styles, which are sets of colour profiles for JPEG files.

Standard	Vivid
Neutral	Clear
Deep	Light
Portrait	Landscape
Sunset	Night
Autumn	B&W
Sepia

Picture Effects

The Sony A6400 offers 13 Picture Effects, some with additional sub options: Toy camera (normal, cool, warm, green, magenta), Pop color, Posterization (mono, colour), Retro photo, Soft high-key, Partial color (red, green, blue, yellow), High-contrast mono, Soft focus (low, mid, high), HDR painting (low, mid, high), Rich-tone mono, Miniature (top, middle horizontal, bottom, left, middle vertical, right), Watercolor, and Illustration (low, mid, high).

Off	Toy Camera
Pop Color	Posterization
Retro	Soft High-key
Partial Color (Red)	High Contrast Mono
Soft Focus	HDR Painting
Rich-tone Mono	Miniature
Watercolor	Illustration