Sony A6400 vs RX0

The Sony Alpha A6400 and the Sony Cyber-shot DSC-RX0 are two digital cameras that were officially introduced, respectively, in January 2019 and August 2017. The A6400 is a mirrorless interchangeable lens camera, while the RX0 is a fixed lens compact. The cameras are based on an APS-C (A6400) and an one-inch (RX0) sensor. The A6400 has a resolution of 24 megapixels, whereas the RX0 provides 15.4 MP.

Below is an overview of the main specs of the two cameras as a starting point for the comparison.

Headline Specifications

Sony A6400		Sony RX0
Mirrorless system camera		Fixed lens compact camera
Sony E mount lenses		24mm f/4.0
24 MP – APS-C sensor		15.4 MP – 1" sensor
4K/30p Video		1080/60p Video
ISO 100-32,000 (100 - 102,400)		ISO 125-12,800
Electronic viewfinder (2359k dots)		No viewfinder, LCD framing
3.0" LCD – 922k dots		1.5" LCD – 230k dots
Tilting touchscreen		Fixed screen (not touch-sensitive)
11 shutter flaps per second		5.5 shutter flaps per second
Weathersealed body		Waterproof body (10m)
410 shots per battery charge		240 shots per battery charge
120 x 67 x 50 mm, 403 g		59 x 41 x 30 mm, 110 g

Check A6400 price at
amazon.com
Check RX0 offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Sony Alpha A6400 and the Sony Cyber-shot DSC-RX0? Which one should you buy? Read on to find out how these two cameras compare with respect to their body size, their imaging sensors, their shooting features, their input-output connections, and their reception by expert reviewers.

Body comparison

The side-by-side display below illustrates the physical size and weight of the Sony A6400 and the Sony RX0. The two cameras are presented according to their relative size. Three successive views from the front, the top, and the rear are shown. All width, height and depth dimensions are rounded to the nearest millimeter.

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Sony RX0 is considerably smaller (70 percent) than the Sony A6400. In this context, it is worth noting that both cameras are splash and dust-proof and can, hence, be used in inclement weather conditions or harsh environments. More than that, the RX0 is water-proof up to 10m and can, thus, be used for underwater photography.

The above size and weight comparisons are to some extent incomplete and possibly misleading, as the RX0 has a lens built in, whereas the A6400 is an interchangeable lens camera that requires a separate lens. Attaching the latter will add extra weight and bulk to the setup. You can compare the optics available for the A6400 and their specifications in the Sony E-Mount Lens Catalog.

Concerning battery life, the A6400 gets 410 shots out of its Sony NP-FW50 battery, while the RX0 can take 240 images on a single charge of its Sony NP-BJ1 power pack. The battery packs of both cameras can be charged via USB, which can be very convenient when travelling.

The following table provides a synthesis of the main physical specifications of the two cameras and other similar ones. In case you want to display and compare another camera duo, you can use the CAM-parator app to select your camera combination among a large number of options.

Body Specifications

		Camera Model	Camera Width	Camera Height	Camera Depth	Camera Weight	Battery Life	Weather Sealing	Camera Launch	Launch Price (USD)	Street Price
1.		Sony A6400	120 mm	67 mm	50 mm	403 g	410	Y	Jan 2019	899	amazon.com
2.		Sony RX0	59 mm	41 mm	30 mm	110 g	240	Y	Aug 2017	699	ebay.com
3.		Fujifilm X-T30	118 mm	83 mm	47 mm	383 g	380	n	Feb 2019	899	ebay.com
4.		Nikon D5300	125 mm	98 mm	76 mm	480 g	600	n	Oct 2013	799	ebay.com
5.		Sony A3000	128 mm	91 mm	85 mm	411 g	470	n	Aug 2013	329	ebay.com
6.		Sony A5100	110 mm	63 mm	36 mm	283 g	400	n	Aug 2014	549	ebay.com
7.		Sony A6000	120 mm	67 mm	45 mm	344 g	360	n	Feb 2014	599	ebay.com
8.		Sony A6100	120 mm	67 mm	59 mm	396 g	420	n	Aug 2019	749	ebay.com
9.		Sony A6300	120 mm	67 mm	49 mm	404 g	400	Y	Feb 2016	999	ebay.com
10.		Sony NEX-5R	111 mm	59 mm	39 mm	276 g	330	n	Aug 2012	749	ebay.com
11.		Sony NEX-6	120 mm	67 mm	43 mm	345 g	360	n	Sep 2012	999	ebay.com
12.		Sony NEX-7	120 mm	67 mm	43 mm	400 g	430	n	Aug 2011	1,349	ebay.com
13.		Sony RX0 II	59 mm	41 mm	35 mm	132 g	240	Y	Mar 2019	699	amazon.com
14.		Sony RX10	129 mm	88 mm	102 mm	813 g	420	Y	Oct 2013	1,299	ebay.com
15.		Sony RX10 II	129 mm	88 mm	102 mm	813 g	400	Y	Jun 2015	1,299	ebay.com
16.		Sony RX10 III	133 mm	94 mm	127 mm	1051 g	420	Y	Mar 2016	1,499	ebay.com
17.		Sony RX10 IV	133 mm	94 mm	145 mm	1095 g	400	Y	Sep 2017	1,699	amazon.com
Note: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.
Convert to Imperial

Any camera decision will naturally be influenced heavily by the price. The listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The RX0 was launched at a lower price than the A6400, despite having a lens built in. Usually, retail prices stay at first close to the launch price, but after several months, discounts become available. Later in the product cycle and, in particular, when the replacement model is about to appear, further discounting and stock clearance sales often push the camera price considerably down.

Sensor comparison

The size of the imaging sensor is a crucial determinant of image quality. A large sensor will generally have larger individual pixels that offer better low-light sensitivity, provide wider dynamic range, and have richer color-depth than smaller pixels in a sensor of the same technological generation. Moreover, a large sensor camera will give the photographer more control over depth-of-field in the image and, thus, the ability to better isolate a subject from the background. On the downside, larger sensors are more costly to manufacture and tend to lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the Sony A6400 features an APS-C sensor and the Sony RX0 an one-inch sensor. The sensor area in the RX0 is 68 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.5 and 2.7. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

With 24MP, the A6400 offers a higher resolution than the RX0 (15.4MP), but the A6400 nevertheless has larger individual pixels (pixel pitch of 3.91μm versus 2.74μm for the RX0) due to its larger sensor. Moreover, the A6400 is a somewhat more recent model (by 1 year and 4 months) than the RX0, and its sensor might have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixels.

The resolution advantage of the Sony A6400 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A6400 for good quality output (200 dots per inch) amounts to 30 x 20 inches or 76.2 x 50.8 cm, for very good quality (250 dpi) 24 x 16 inches or 61 x 40.6 cm, and for excellent quality (300 dpi) 20 x 13.3 inches or 50.8 x 33.9 cm. The corresponding values for the Sony RX0 are 24 x 16 inches or 61 x 40.6 cm for good quality, 19.2 x 12.8 inches or 48.8 x 32.5 cm for very good quality, and 16 x 10.7 inches or 40.6 x 27.1 cm for excellent quality prints.

The A6400 has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.

The Sony Alpha A6400 has a native sensitivity range from ISO 100 to ISO 32000, which can be extended to ISO 100-102400. The corresponding ISO settings for the Sony Cyber-shot DSC-RX0 are ISO 125 to ISO 12800 (no boost).

Technology-wise, both cameras are equipped with CMOS (Complementary Metal–Oxide–Semiconductor) sensors. Both cameras use a Bayer filter for capturing RGB colors on a square grid of photosensors. This arrangement is found in most digital cameras.

Consistent information on actual sensor performance is available from DXO Mark for many cameras. This service determines an overall sensor rating, as well as sub-scores for low-light sensitivity ("DXO Sports"), dynamic range ("DXO Landscape"), and color depth ("DXO Portrait"). Of the two cameras under review, the A6400 provides substantially higher image quality than the RX0, with an overall score that is 15 points higher. This advantage is based on 1.6 bits higher color depth, 1.2 EV in additional dynamic range, and 1.4 stops in additional low light sensitivity. The following table provides an overview of the physical sensor characteristics, as well as the sensor quality measurements for a selection of comparators.

Sensor Characteristics

		Camera Model	Sensor Class	Resolution (MP)	Horiz. Pixels	Vert. Pixels	Video Format	DXO Portrait	DXO Landscape	DXO Sports	DXO Overall
1.		Sony A6400	APS-C	24.0	6000	4000	4K/30p	24.0	13.6	1431	83
2.		Sony RX0	1-inch	15.4	4800	3200	1080/60p	22.4	12.4	548	68
3.		Fujifilm X-T30	APS-C	26.0	6240	4160	4K/30p	24.1	13.5	1895	83
4.		Nikon D5300	APS-C	24.0	6000	4000	1080/60p	24.0	13.9	1338	83
5.		Sony A3000	APS-C	19.8	5456	3632	1080/60i	23.7	12.8	1068	78
6.		Sony A5100	APS-C	24.0	6000	4000	1080/60p	23.8	12.7	1347	80
7.		Sony A6000	APS-C	24.0	6000	4000	1080/60p	24.1	13.1	1347	82
8.		Sony A6100	APS-C	24.0	6000	4000	4K/30p	24.1	13.6	1947	84
9.		Sony A6300	APS-C	24.0	6000	4000	4K/30p	24.4	13.7	1437	85
10.		Sony NEX-5R	APS-C	16.0	4912	3264	1080/60i	23.7	13.1	910	78
11.		Sony NEX-6	APS-C	16.0	4912	3264	1080/60i	23.7	13.1	1018	78
12.		Sony NEX-7	APS-C	24.0	6000	4000	1080/60i	24.1	13.4	1016	81
13.		Sony RX0 II	1-inch	15.4	4800	3200	4K/30p	22.1	12.4	555	65
14.		Sony RX10	1-inch	20.0	5472	3648	1080/60p	22.9	12.6	474	69
15.		Sony RX10 II	1-inch	20.0	5472	3648	4K/30p	23.0	12.6	531	70
16.		Sony RX10 III	1-inch	20.0	5472	3648	4K/30p	23.1	12.6	472	70
17.		Sony RX10 IV	1-inch	20.0	5472	3648	4K/30p	22.0	12.2	408	63
Note: DXO values in italics represent estimates based on sensor size and age.

Many modern cameras are not only capable of taking still images, but also of capturing video footage. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, but the A6400 provides a higher video resolution than the RX0. It can shoot video footage at 4K/30p, while the RX0 is limited to 1080/60p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a range of features. For example, the A6400 has an electronic viewfinder (2359k dots), which can be very helpful when shooting in bright sunlight. In contrast, the RX0 relies on live view and the rear LCD for framing. The following table reports on some other key feature differences and similarities of the Sony A6400, the Sony RX0, and comparable cameras.

Core Features

		Camera Model	Viewfinder (Type or 000 dots)	Control Panel (yes/no)	LCD Specifications (inch/000 dots)	LCD Attach- ment	Touch Screen (yes/no)	Max Shutter Speed *	Max Shutter Flaps *	Built-in Flash (yes/no)	Built-in Image Stab
1.		Sony A6400	2359	n	3.0 / 922	tilting	Y	1/4000s	11.0/s	Y	n
2.		Sony RX0	none	n	1.5 / 230	fixed	n	..	5.5/s	n	n
3.		Fujifilm X-T30	2360	n	3.0 / 1040	tilting	Y	1/4000s	8.0/s	Y	n
4.		Nikon D5300	optical	n	3.2 / 1037	swivel	n	1/4000s	5.0/s	Y	n
5.		Sony A3000	202	n	3.0 / 230	fixed	n	1/4000s	2.5/s	Y	n
6.		Sony A5100	none	n	3.0 / 922	tilting	Y	1/4000s	6.0/s	Y	n
7.		Sony A6000	1440	n	3.0 / 922	tilting	n	1/4000s	11.0/s	Y	n
8.		Sony A6100	1440	n	3.0 / 922	tilting	Y	1/4000s	11.0/s	Y	n
9.		Sony A6300	2359	n	3.0 / 922	tilting	n	1/4000s	11.0/s	Y	n
10.		Sony NEX-5R	optional	n	3.0 / 920	tilting	Y	1/4000s	10.0/s	n	n
11.		Sony NEX-6	2359	n	3.0 / 921	tilting	n	1/4000s	10.0/s	Y	n
12.		Sony NEX-7	2359	n	3.0 / 921	tilting	n	1/4000s	10.0/s	Y	n
13.		Sony RX0 II	none	n	1.5 / 230	tilting	n	..	5.5/s	n	n
14.		Sony RX10	1440	Y	3.0 / 1229	tilting	n	1/3200s	10.0/s	Y	Y
15.		Sony RX10 II	2359	Y	3.0 / 1229	tilting	n	1/3200s	14.0/s	Y	Y
16.		Sony RX10 III	2359	Y	3.0 / 1229	tilting	n	1/2000s	14.0/s	Y	Y
17.		Sony RX10 IV	2359	Y	3.0 / 1440	tilting	Y	1/2000s	24.0/s	Y	Y
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One difference between the cameras concerns the presence of an on-board flash. The A6400 has one, while the RX0 does not. While the built-in flash of the A6400 is not very powerful, it can at times be useful as a fill-in light.

The reported shutter speed information refers to the use of the mechanical shutter. Yet, some cameras only have an electronic shutter, while others have an electronic shutter in addition to a mechanical one. In fact, both cameras under consideration feature an electronic shutter, which makes completely silent shooting possible. However, this mode is less suitable for photographing moving objects (risk of rolling shutter) or shooting under artificial light sources (risk of flickering).

The A6400 writes its imaging data to SDXC or Memory Stick PRO Duo cards, while the RX0 uses micro SDXC or Memory Stick Micro cards. Both cameras can use UHS-I cards, which provide for Ultra High Speed data transfer of up to 104 MB/s.

Connectivity comparison

For some imaging applications, the extent to which a camera can communicate with its environment can be an important aspect in the camera decision process. The table below provides an overview of the connectivity of the Sony Alpha A6400 and Sony Cyber-shot DSC-RX0 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.

Input-Output Connections

		Camera Model	Hotshoe Port	Internal Mic / Speaker	Microphone Port	Headphone Port	HDMI Port	USB Port	WiFi Support	NFC Support	Bluetooth Support
1.		Sony A6400	Y	stereo / mono	Y	-	micro	2.0	Y	Y	Y
2.		Sony RX0	-	stereo / mono	Y	-	micro	2.0	Y	-	Y
3.		Fujifilm X-T30	Y	stereo / mono	Y	-	micro	3.1	Y	-	Y
4.		Nikon D5300	Y	stereo / mono	Y	-	mini	2.0	Y	-	-
5.		Sony A3000	Y	stereo / mono	-	-	mini	2.0	-	-	-
6.		Sony A5100	-	stereo / mono	-	-	micro	2.0	Y	Y	-
7.		Sony A6000	Y	stereo / mono	-	-	micro	2.0	Y	Y	-
8.		Sony A6100	Y	stereo / mono	Y	-	micro	2.0	Y	Y	Y
9.		Sony A6300	Y	stereo / mono	Y	-	micro	2.0	Y	Y	-
10.		Sony NEX-5R	Y	stereo / mono	-	-	mini	2.0	Y	-	-
11.		Sony NEX-6	Y	stereo / mono	-	-	mini	2.0	Y	-	-
12.		Sony NEX-7	Y	stereo / mono	Y	-	mini	2.0	-	-	-
13.		Sony RX0 II	-	stereo / mono	Y	-	micro	2.0	Y	-	Y
14.		Sony RX10	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
15.		Sony RX10 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
16.		Sony RX10 III	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
17.		Sony RX10 IV	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-

It is notable that the A6400 has a hotshoe, while the RX0 does not. This socket makes it possible to easily attach optional accessories, such as an external flash gun.

The A6400 is a recent model that features in the current product line-up of Sony. In contrast, the RX0 has been discontinued (but can be found pre-owned on ebay). As a replacement in the same line of cameras, the RX0 was succeeded by the Sony RX0 II. Further information on the features and operation of the A6400 and RX0 can be found, respectively, in the Sony A6400 Manual (free pdf) or the online Sony RX0 Manual.

Review summary

So what conclusions can be drawn? Which of the two cameras – the Sony A6400 or the Sony RX0 – has the upper hand? Is one clearly better than the other? Below is a summary of the relative strengths of each of the two contestants.

Reasons to prefer the Sony Alpha A6400:

• More detail: Offers more megapixels (24 vs 15.4MP) with a 25% higher linear resolution.
• Better image quality: Scores substantially higher (15 points) in the DXO overall assessment.
• Richer colors: Generates images with noticeably better colors (1.6 bits more color depth).
• More dynamic range: Captures a larger spectrum of light and dark details (1.2 EV of extra DR).
• Better low-light sensitivity: Requires less light for good images (1.4 stops ISO advantage).
• Better video: Provides higher definition movie capture (4K/30p vs 1080/60p).
• Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
• Easier framing: Has an electronic viewfinder for image composition and settings control.
• Larger screen: Has a bigger rear LCD (3.0" vs 1.5") for image review and settings control.
• More detailed LCD: Has a higher resolution rear screen (922k vs 230k dots).
• More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
• Fewer buttons to press: Is equipped with a touch-sensitive rear screen to facilitate handling.
• More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
• Faster burst: Shoots at higher frequency (11 vs 5.5 flaps/sec) to capture the decisive moment.
• More flexible: Accepts interchangeable lenses, so that lens characteristics can be altered.
• Longer lasting: Can take more shots (410 versus 240) on a single battery charge.
• Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
• Better lighting: Features a hotshoe and can thus hold and trigger an external flash gun.
• Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
• More modern: Is somewhat more recent (announced 1 year and 4 months after the RX0).

Arguments in favor of the Sony Cyber-shot DSC-RX0:

• Ready to shoot: Has an integrated lens, whereas the A6400 necessitates an extra lens.
• More compact: Is smaller (59x41mm vs 120x67mm) and will fit more readily into a bag.
• Less heavy: Has a lower weight even though it has a lens built in (unlike the A6400).
• Water-proof: Is rugged and sealed and can thus be used for underwater photography (up to 10m).
• More affordable: Was introduced at a lower price, despite coming with a built-in lens.
• More heavily discounted: Has been on the market for longer (launched in August 2017).

If the number of relative strengths (bullet points above) is taken as a guide, the A6400 is the clear winner of the match-up (20 : 6 points). However, the relevance of individual strengths will vary across photographers, so that you might want to apply your own weighing scheme to the summary points when reflecting and deciding on a new camera. A professional wildlife photographer will view the differences between cameras in a way that diverges from the perspective of a family photog, and a person interested in architecture has distinct needs from a sports shooter. Hence, the decision which camera is best and worth buying is often a very personal one.

How about other alternatives? Do the specifications of the Sony A6400 and the Sony RX0 place the cameras among the top in their class? Find out in the latest Best Mirrorless Interchangeable Lens Camera and Best Prime Lens Compact Camera listings whether the two cameras rank among the cream of the crop.

In any case, while the specs-based evaluation of cameras can be instructive in revealing their potential as photographic tools, it remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the A6400 or the RX0. At times, user reviews, such as those published at amazon, address these issues in a useful manner, but such feedback is on many occasions incomplete, inconsistent, and unreliable.

Expert reviews

This is why expert reviews are important. The table below provides a synthesis of the camera assessments of some of the best known photo-gear review sites (amateurphotographer [AP], cameralabs [CL], digitalcameraworld [DCW], dpreview [DPR], ephotozine [EPZ], photographyblog [PB]). As can be seen, the professional reviewers agree in many cases on the quality of different cameras, but sometimes their assessments diverge, reinforcing the earlier point that a camera decision is often a very personal choice.

Expert Camera Reviews

		Camera   Model	AP   score	CL   score	DCW   score	DPR   score	EPZ   score	PB   score	Camera Launch	Launch Price (USD)	Street Price
1.		Sony A6400	4/5	+	4/5	85/100	4.5/5	4/5	Jan 2019	899	amazon.com
2.		Sony RX0	..	..	..	..	3.5/5	4/5	Aug 2017	699	ebay.com
3.		Fujifilm X-T30	5/5	+ +	5/5	84/100	4.5/5	4.5/5	Feb 2019	899	ebay.com
4.		Nikon D5300	4/5	+ +	..	79/100	4.5/5	4.5/5	Oct 2013	799	ebay.com
5.		Sony A3000	3/5	+	..	..	4/5	4/5	Aug 2013	329	ebay.com
6.		Sony A5100	4.5/5	+	..	..	4.5/5	5/5	Aug 2014	549	ebay.com
7.		Sony A6000	5/5	+	4.5/5	80/100	4.5/5	5/5	Feb 2014	599	ebay.com
8.		Sony A6100	..	..	4/5	82/100	4/5	5/5	Aug 2019	749	ebay.com
9.		Sony A6300	4.5/5	+	..	85/100	5/5	5/5	Feb 2016	999	ebay.com
10.		Sony NEX-5R	..	..	..	..	4.5/5	4.5/5	Aug 2012	749	ebay.com
11.		Sony NEX-6	5/5	+ +	..	78/100	4.5/5	4.5/5	Sep 2012	999	ebay.com
12.		Sony NEX-7	5/5	+ +	..	81/100	4.5/5	5/5	Aug 2011	1,349	ebay.com
13.		Sony RX0 II	..	..	..	..	3.5/5	4/5	Mar 2019	699	amazon.com
14.		Sony RX10	5/5	+	..	80/100	4.5/5	4.5/5	Oct 2013	1,299	ebay.com
15.		Sony RX10 II	5/5	+ +	..	82/100	4.5/5	4/5	Jun 2015	1,299	ebay.com
16.		Sony RX10 III	5/5	+	..	84/100	4.5/5	4.5/5	Mar 2016	1,499	ebay.com
17.		Sony RX10 IV	5/5	+	3.5/5	84/100	4.5/5	5/5	Sep 2017	1,699	amazon.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

Care should be taken when interpreting the review scores above, though. The ratings were established in reference to similarly priced cameras that were available in the market at the time of the review. Hence, a score should always be seen in the context of the camera's market launch date and its price, and comparing ratings of very distinct cameras or ones that are far apart in terms of their release date have little meaning. It should also be noted that some of the review sites have over time altered the way they render their verdicts.

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Other camera comparisons

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