Sony RX100 III vs A7S

The Sony Cyber-shot DSC-RX100 III and the Sony Alpha A7S are two digital cameras that were revealed to the public, respectively, in May 2014 and April 2014. The RX100 III is a fixed lens compact, while the A7S is a mirrorless interchangeable lens camera. The cameras are based on an one-inch (RX100 III) and a full frame (A7S) sensor. The RX100 III has a resolution of 20 megapixels, whereas the A7S provides 12 MP.

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

Headline Specifications

Sony RX100 III		Sony A7S
Fixed lens compact camera		Mirrorless system camera
24-70mm f/1.8-2.8		Sony E mount lenses
20 MP – 1" sensor		12 MP – Full Frame sensor
1080/60p Video		1080/60p Video
ISO 100-12,800 (80 - 25,600)		ISO 100-102,400 (50 - 409,600)
Electronic viewfinder (1440k dots)		Electronic viewfinder (2400k dots)
3.0" LCD – 1229k dots		3.0" LCD – 921k dots
Tilting screen (no touchscreen)		Tilting screen (no touchscreen)
10 shutter flaps per second		5 shutter flaps per second
not weather sealed		Weathersealed body
320 shots per battery charge		380 shots per battery charge
102 x 58 x 41 mm, 290 g		127 x 94 x 48 mm, 489 g

Check RX100 III offers at
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Going beyond this snapshot of core features and characteristics, what are the differences between the Sony Cyber-shot DSC-RX100 III and the Sony Alpha A7S? 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 physical size and weight of the Sony RX100 III and the Sony A7S are illustrated in the side-by-side display below. 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 measures 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 A7S is considerably larger (102 percent) than the Sony RX100 III. It is noteworthy in this context that the A7S is splash and dust-proof, while the RX100 III does not feature any corresponding weather-sealing.

The above size and weight comparisons are to some extent incomplete and possibly misleading, as the RX100 III has a lens built in, whereas the A7S 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 A7S and their specifications in the Sony FE Lens Catalog.

Concerning battery life, the RX100 III gets 320 shots out of its Sony NP-BX1 battery, while the A7S can take 380 images on a single charge of its Sony NP-FW50 power pack. The battery packs of both cameras can be charged via USB, which can be very convenient when travelling.

The adjacent table lists the principal physical characteristics of the two cameras alongside a wider set of alternatives. If you would like to visualize and compare a different camera combination, you can navigate to the CAM-parator app and make your selection from a broad list of cameras there.

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 RX100 III	102 mm	58 mm	41 mm	290 g	320	n	May 2014	799	ebay.com
2.		Sony A7S	127 mm	94 mm	48 mm	489 g	380	Y	Apr 2014	2,499	ebay.com
3.		Canon G5 X	112 mm	76 mm	44 mm	353 g	210	n	Oct 2015	799	ebay.com
4.		Canon G7 X	103 mm	60 mm	40 mm	304 g	210	n	Sep 2014	699	ebay.com
5.		Nikon Df	144 mm	110 mm	67 mm	760 g	1400	Y	Nov 2013	2,749	ebay.com
6.		Panasonic FZ1000	137 mm	99 mm	131 mm	831 g	360	n	Jun 2014	899	ebay.com
7.		Sony A7	127 mm	94 mm	48 mm	474 g	340	Y	Oct 2013	1,699	ebay.com
8.		Sony A7R	127 mm	94 mm	48 mm	465 g	340	Y	Oct 2013	2,299	ebay.com
9.		Sony A7S II	127 mm	96 mm	60 mm	627 g	370	Y	Sep 2015	2,999	ebay.com
10.		Sony RX100	102 mm	58 mm	36 mm	240 g	330	n	Jun 2012	649	ebay.com
11.		Sony RX100 II	102 mm	58 mm	38 mm	281 g	350	n	Jun 2013	749	ebay.com
12.		Sony RX100 IV	102 mm	58 mm	41 mm	298 g	280	n	Jun 2015	999	ebay.com
13.		Sony RX100 V	102 mm	58 mm	41 mm	299 g	220	n	Oct 2016	999	ebay.com
14.		Sony RX100 VII	102 mm	58 mm	43 mm	302 g	260	n	Jul 2019	1,199	amazon.com
15.		Sony ZV-1	105 mm	60 mm	44 mm	294 g	260	n	May 2020	799	ebay.com
16.		Sony ZV-1 II	106 mm	60 mm	47 mm	292 g	290	n	May 2023	899	amazon.com
17.		Sony ZV-E1	121 mm	72 mm	54 mm	483 g	570	Y	Mar 2023	2,199	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

The price is, of course, an important factor in any camera decision. The retail prices at the time of the camera’s release place the model in the market relative to other models in the producer’s line-up and the competition. The RX100 III was launched at a lower price than the A7S, despite having a lens built in. Normally, street prices remain initially close to the MSRP, but after a couple of months, the first discounts appear. 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 imaging sensor is at the core of digital cameras and its size is one of the main determining factors of image quality. A large sensor will tend to have larger individual pixels that provide better low-light sensitivity, wider dynamic range, and richer color-depth than smaller pixel-units in a sensor of the same technological generation. Furthermore, a large sensor camera will give the photographer more possibilities to use shallow depth-of-field in order to isolate a subject from the background. On the downside, larger sensors tend to be more expensive and lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the Sony RX100 III features an one-inch sensor and the Sony A7S a full frame sensor. The sensor area in the A7S is 638 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 2.7 and 1.0. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

Despite having a smaller sensor, the Sony RX100 III offers a higher resolution of 20 megapixels, compared with 12 MP of the Sony A7S. This megapixels advantage comes at the cost of a higher pixel density and a smaller size of the individual pixel (with a pixel pitch of 2.41μm versus 8.45μm for the A7S). It is noteworthy in this context that the two cameras were released in close succession, so that their sensors are from the same technological generation.

The resolution advantage of the Sony RX100 III implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the RX100 III for good quality output (200 dots per inch) amounts to 27.4 x 18.2 inches or 69.5 x 46.3 cm, for very good quality (250 dpi) 21.9 x 14.6 inches or 55.6 x 37.1 cm, and for excellent quality (300 dpi) 18.2 x 12.2 inches or 46.3 x 30.9 cm. The corresponding values for the Sony A7S are 21.2 x 14.2 inches or 53.8 x 36 cm for good quality, 17 x 11.3 inches or 43.1 x 28.8 cm for very good quality, and 14.1 x 9.4 inches or 35.9 x 24 cm for excellent quality prints.

The Sony Cyber-shot DSC-RX100 III has a native sensitivity range from ISO 100 to ISO 12800, which can be extended to ISO 80-25600. The corresponding ISO settings for the Sony Alpha A7S are ISO 100 to ISO 102400, with the possibility to increase the ISO range to 50-409600.

In terms of underlying technology, the RX100 III is build around a BSI-CMOS sensor, while the A7S uses a CMOS imager. Both cameras use a Bayer filter for capturing RGB colors on a square grid of photosensors. This arrangement is found in most digital cameras.

Since 2007, DXO Mark has published sensor performance measurements that have been derived using a consistent methodology. This service assesses and scores the color depth ("DXO Portrait"), dynamic range ("DXO Landscape"), and low-light sensitivity ("DXO Sports") of camera sensors, and also publishes an overall camera score. Of the two cameras under consideration, the A7S offers substantially better image quality than the RX100 III (overall score 20 points higher). The advantage is based on 1.5 bits higher color depth, 0.9 EV in additional dynamic range, and 2.9 stops in additional low light sensitivity. The adjacent table reports on the physical sensor characteristics and the outcomes of the DXO sensor quality tests for a sample of comparator-cameras.

Sensor Characteristics

		Camera Model	Sensor Class	Resolution (MP)	Horiz. Pixels	Vert. Pixels	Video Format	DXO Portrait	DXO Landscape	DXO Sports	DXO Overall
1.		Sony RX100 III	1-inch	20.0	5472	3648	1080/60p	22.4	12.3	495	67
2.		Sony A7S	Full Frame	12.0	4240	2832	1080/60p	23.9	13.2	3702	87
3.		Canon G5 X	1-inch	20.0	5472	3648	1080/60p	21.4	12.3	471	62
4.		Canon G7 X	1-inch	20.0	5472	3648	1080/60p	23.0	12.7	556	71
5.		Nikon Df	Full Frame	16.2	4928	3280	none	24.6	13.1	3279	89
6.		Panasonic FZ1000	1-inch	20.0	5472	3648	4K/30p	22.1	11.7	517	64
7.		Sony A7	Full Frame	24.0	6000	4000	1080/60p	24.8	14.2	2248	90
8.		Sony A7R	Full Frame	36.2	7360	4912	1080/60p	25.6	14.1	2746	95
9.		Sony A7S II	Full Frame	12.0	4240	2832	4K/30p	23.6	13.3	2993	85
10.		Sony RX100	1-inch	20.0	5472	3648	1080/60p	22.6	12.4	390	66
11.		Sony RX100 II	1-inch	20.0	5472	3648	1080/60p	22.5	12.4	483	67
12.		Sony RX100 IV	1-inch	20.0	5472	3648	4K/30p	22.8	12.6	591	70
13.		Sony RX100 V	1-inch	20.0	5472	3648	4K/30p	22.8	12.4	586	70
14.		Sony RX100 VII	1-inch	20.0	5472	3648	4K/30p	21.8	12.4	418	63
15.		Sony ZV-1	1-inch	20.0	5472	3648	4K/30p	22.2	12.6	669	66
16.		Sony ZV-1 II	1-inch	20.0	5472	3648	4K/30p	22.3	12.9	965	67
17.		Sony ZV-E1	Full Frame	12.0	4240	2832	4K/60p	25.4	14.6	3181	96
Note: DXO values in italics represent estimates based on sensor size and age.

Many modern cameras cannot only take still pictures, but also record videos. The two cameras under consideration both have sensors whose read-out speed is fast enough to capture moving pictures, and both provide the same movie specifications (1080/60p).

Feature comparison

Beyond body and sensor, cameras can and do differ across a range of features. The two cameras under review are similar with respect to both having an electronic viewfinder. However, the one in the A7S offers a substantially higher resolution than the one in the RX100 III (2400k vs 1440k dots). The table below summarizes some of the other core capabilities of the Sony RX100 III and Sony A7S in connection with corresponding information for a sample of similar 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 RX100 III	1440	n	3.0 / 1229	tilting	n	1/2000s	10.0/s	Y	Y
2.		Sony A7S	2400	n	3.0 / 921	tilting	n	1/8000s	5.0/s	n	n
3.		Canon G5 X	2360	n	3.0 / 1040	swivel	Y	1/2000s	5.9/s	Y	Y
4.		Canon G7 X	none	n	3.0 / 1040	tilting	Y	1/2000s	6.5/s	Y	Y
5.		Nikon Df	optical	Y	3.2 / 921	fixed	n	1/4000s	5.5/s	n	n
6.		Panasonic FZ1000	2359	n	3.0 / 921	swivel	n	1/4000s	12.0/s	Y	Y
7.		Sony A7	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	n
8.		Sony A7R	2400	n	3.0 / 1230	tilting	n	1/8000s	4.0/s	n	n
9.		Sony A7S II	2400	n	3.0 / 1229	tilting	n	1/8000s	5.0/s	n	Y
10.		Sony RX100	none	n	3.0 / 1229	fixed	n	1/2000s	10.0/s	Y	Y
11.		Sony RX100 II	optional	n	3.0 / 1229	tilting	n	1/2000s	10.0/s	Y	Y
12.		Sony RX100 IV	2359	n	3.0 / 1228	tilting	n	1/2000s	16.0/s	Y	Y
13.		Sony RX100 V	2359	n	3.0 / 1229	tilting	n	1/2000s	24.0/s	Y	Y
14.		Sony RX100 VII	2359	n	3.0 / 921	tilting	Y	1/2000s	90.0/s	Y	Y
15.		Sony ZV-1	none	n	3.0 / 922	swivel	Y	1/2000s	24.0/s	n	n
16.		Sony ZV-1 II	none	n	3.0 / 922	swivel	Y	1/2000s	24.0/s	n	n
17.		Sony ZV-E1	none	n	3.0 / 1037	swivel	Y	1/8000s	10.0/s	n	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 RX100 III has one, while the A7S does not. While the built-in flash of the RX100 III 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, the A7S is one of those camera that have an additional 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).

Concerning the storage of imaging data, both the RX100 III and the A7S write their files to SDXC or Memory Stick PRO Duo 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 Cyber-shot DSC-RX100 III and Sony Alpha A7S 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 RX100 III	-	stereo / mono	-	-	micro	2.0	Y	Y	-
2.		Sony A7S	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
3.		Canon G5 X	Y	stereo / mono	-	-	mini	2.0	Y	Y	-
4.		Canon G7 X	-	stereo / mono	-	-	micro	2.0	Y	Y	-
5.		Nikon Df	Y	- / -	-	-	mini	2.0	-	-	-
6.		Panasonic FZ1000	Y	stereo / mono	Y	-	micro	2.0	Y	Y	-
7.		Sony A7	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
8.		Sony A7R	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
9.		Sony A7S II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
10.		Sony RX100	-	stereo / mono	-	-	micro	2.0	-	-	-
11.		Sony RX100 II	Y	stereo / mono	-	-	micro	2.0	Y	Y	-
12.		Sony RX100 IV	-	stereo / mono	-	-	micro	2.0	Y	Y	-
13.		Sony RX100 V	-	stereo / mono	-	-	micro	2.0	Y	Y	-
14.		Sony RX100 VII	-	stereo / mono	Y	-	micro	2.0	Y	Y	Y
15.		Sony ZV-1	Y	stereo / mono	Y	-	micro	2.0	Y	-	Y
16.		Sony ZV-1 II	Y	stereo / mono	Y	-	micro	2.0	Y	-	Y
17.		Sony ZV-E1	Y	stereo / mono	Y	Y	micro	3.2	Y	-	Y

It is notable that the A7S has a microphone port, which can help to improve the quality of audio recordings by attaching an external microphone. The RX100 III does not feature such a mic input.

Both the RX100 III and the A7S have been discontinued, but can regularly be found used on ebay. The A7S was replaced by the Sony A7S II, while the RX100 III was followed by the Sony RX100 IV. Further information on the features and operation of the RX100 III and A7S can be found, respectively, in the Sony RX100 III Manual (free pdf) or the online Sony A7S Manual.

Review summary

So what conclusions can be drawn? Is the Sony RX100 III better than the Sony A7S or vice versa? The listing below highlights the relative strengths of the two models.

Reasons to prefer the Sony Cyber-shot DSC-RX100 III:

• More detail: Offers more megapixels (20 vs 12MP) with a 29% higher linear resolution.
• More detailed LCD: Has a higher resolution rear screen (1229k vs 921k dots).
• More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
• Faster burst: Shoots at higher frequency (10 vs 5 flaps/sec) to capture the decisive moment.
• Ready to shoot: Has a lens built-in, whereas the A7S requires a separate lens.
• More compact: Is smaller (102x58mm vs 127x94mm) and thus needs less room in the bag.
• Less heavy: Is lighter even though it comes with a built-in lens (unlike the A7S).
• Sharper images: Has hand-shake reducing image stabilization built-in.
• Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
• More affordable: Was introduced at a lower price, despite coming with a built-in lens.

Advantages of the Sony Alpha A7S:

• Better image quality: Scores substantially higher (20 points) in the DXO overall evaluation.
• Richer colors: Generates noticeably more natural colors (1.5 bits more color depth).
• More dynamic range: Captures a broader range of light and dark details (0.9 EV of extra DR).
• Better low-light sensitivity: Can shoot in dim conditions (2.9 stops ISO advantage).
• Better sound: Can connect to an external microphone for higher quality sound recording.
• Better sound control: Has a headphone port that enables audio monitoring while recording.
• More detailed viewfinder: Has higher resolution electronic viewfinder (2400k vs 1440k dots).
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.71x vs 0.59x).
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/2000s) to freeze action.
• Less disturbing: Has an electronic shutter option for completely silent shooting.
• More flexible: Takes interchangeable lenses and can thus be used with specialty optics.
• Longer lasting: Gets more shots (380 versus 320) out of a single battery charge.
• Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
• Better lighting: Features a hotshoe and can thus hold and trigger an external flash gun.

If the count of individual advantages (bullet points above) is taken as a guide, the A7S is the clear winner of the contest (14 : 10 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 RX100 III and the Sony A7S place the cameras among the top in their class? Find out in the latest Best Travel-Zoom Camera and Best Mirrorless Interchangeable Lens Camera listings whether the two cameras rank among the cream of the crop.

In any case, while the comparison of the spec-sheets of cameras can offer a general idea of their imaging potential, it remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the RX100 III or the A7S. 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 hands-on reviews by experts 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 RX100 III	5/5	+ +	..	82/100	4.5/5	5/5	May 2014	799	ebay.com
2.		Sony A7S	4/5	..	..	86/100	4.5/5	5/5	Apr 2014	2,499	ebay.com
3.		Canon G5 X	5/5	+ +	..	78/100	4.5/5	4.5/5	Oct 2015	799	ebay.com
4.		Canon G7 X	4/5	+ +	..	77/100	4.5/5	4.5/5	Sep 2014	699	ebay.com
5.		Nikon Df	4/5	..	..	81/100	4/5	4/5	Nov 2013	2,749	ebay.com
6.		Panasonic FZ1000	4/5	+ +	..	82/100	4.5/5	4.5/5	Jun 2014	899	ebay.com
7.		Sony A7	5/5	+ +	..	80/100	5/5	5/5	Oct 2013	1,699	ebay.com
8.		Sony A7R	5/5	+ +	..	82/100	4.5/5	5/5	Oct 2013	2,299	ebay.com
9.		Sony A7S II	5/5	+	..	..	4.5/5	5/5	Sep 2015	2,999	ebay.com
10.		Sony RX100	5/5	+ +	..	78/100	4/5	5/5	Jun 2012	649	ebay.com
11.		Sony RX100 II	5/5	+ +	..	79/100	4.5/5	4.5/5	Jun 2013	749	ebay.com
12.		Sony RX100 IV	4.5/5	+ +	..	85/100	4/5	4.5/5	Jun 2015	999	ebay.com
13.		Sony RX100 V	4.5/5	+ +	..	83/100	4/5	4.5/5	Oct 2016	999	ebay.com
14.		Sony RX100 VII	4.5/5	..	4/5	..	4/5	5/5	Jul 2019	1,199	amazon.com
15.		Sony ZV-1	4/5	+	4/5	85/100	4/5	4.5/5	May 2020	799	ebay.com
16.		Sony ZV-1 II	4.5/5	..	3.5/5	83/100	3.5/5	4.5/5	May 2023	899	amazon.com
17.		Sony ZV-E1	..	+	4/5	..	..	4.5/5	Mar 2023	2,199	amazon.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

Care should be taken when interpreting the review scores above, though. The ratings are only valid when referring to cameras in the same category and of the same age. Hence, a score should always be seen in the context of the camera's market launch date and its price, and rating-comparisons among cameras that span long time periods or concern very differently equipped models make little sense. 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

Did this review help to inform your camera decision process? If you would like to see a different side-by-side camera review, just make a corresponding selection in the search boxes below. As an alternative, you can also directly jump to any one of the listed comparisons that were previously generated by the CAM-parator tool.

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