Sony A7S vs RX100 IV

The Sony Alpha A7S and the Sony Cyber-shot DSC-RX100 IV are two digital cameras that were officially introduced, respectively, in April 2014 and June 2015. The A7S is a mirrorless interchangeable lens camera, while the RX100 IV is a fixed lens compact. The cameras are based on a full frame (A7S) and an one-inch (RX100 IV) sensor. The A7S has a resolution of 12 megapixels, whereas the RX100 IV provides 20 MP.

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

Headline Specifications

Sony A7S		Sony RX100 IV
Mirrorless system camera		Fixed lens compact camera
Sony E mount lenses		24-70mm f/1.8-2.8
12 MP – Full Frame sensor		20 MP – 1" sensor
1080/60p Video		4K/30p Video
ISO 100-102,400 (50 - 409,600)		ISO 125-12,800 (80 - 25,600)
Electronic viewfinder (2400k dots)		Electronic viewfinder (2359k dots)
3.0" LCD – 921k dots		3.0" LCD – 1228k dots
Tilting screen (no touchscreen)		Tilting screen (no touchscreen)
5 shutter flaps per second		16 shutter flaps per second
Weathersealed body		not weather sealed
380 shots per battery charge		280 shots per battery charge
127 x 94 x 48 mm, 489 g		102 x 58 x 41 mm, 298 g

Check A7S offers at
ebay.com
Check RX100 IV offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Sony Alpha A7S and the Sony Cyber-shot DSC-RX100 IV? 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

An illustration of the physical size and weight of the Sony A7S and the Sony RX100 IV is provided in the side-by-side display below. The two cameras are presented according to their relative size. Three consecutive views from the front, the top, and the rear side 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 RX100 IV is considerably smaller (50 percent) than the Sony A7S. It is worth mentioning in this context that the A7S is splash and dust resistant, while the RX100 IV does not feature any corresponding weather-sealing.

The above size and weight comparisons are to some extent incomplete and possibly misleading, as the RX100 IV 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 A7S gets 380 shots out of its Sony NP-FW50 battery, while the RX100 IV can take 280 images on a single charge of its Sony NP-BX1 power pack. The battery packs of both cameras can be charged via USB, which can be very convenient when travelling.

The table below summarizes the key physical specs of the two cameras alongside a broader set of comparators. 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 A7S	127 mm	94 mm	48 mm	489 g	380	Y	Apr 2014	2,499	ebay.com
2.		Sony RX100 IV	102 mm	58 mm	41 mm	298 g	280	n	Jun 2015	999	ebay.com
3.		Canon G5 X	112 mm	76 mm	44 mm	353 g	210	n	Oct 2015	799	ebay.com
4.		Nikon Df	144 mm	110 mm	67 mm	760 g	1400	Y	Nov 2013	2,749	ebay.com
5.		Panasonic FZ2500	138 mm	102 mm	135 mm	915 g	350	n	Sep 2016	1,199	amazon.com
6.		Sony A7	127 mm	94 mm	48 mm	474 g	340	Y	Oct 2013	1,699	ebay.com
7.		Sony A7 II	127 mm	96 mm	60 mm	599 g	350	Y	Nov 2014	1,999	ebay.com
8.		Sony A7R	127 mm	94 mm	48 mm	465 g	340	Y	Oct 2013	2,299	ebay.com
9.		Sony A7R II	127 mm	96 mm	60 mm	625 g	290	Y	Jun 2015	3,199	ebay.com
10.		Sony A7S II	127 mm	96 mm	60 mm	627 g	370	Y	Sep 2015	2,999	ebay.com
11.		Sony RX1	113 mm	65 mm	70 mm	482 g	270	n	Sep 2012	2,799	ebay.com
12.		Sony RX1R	113 mm	65 mm	70 mm	482 g	270	n	Jun 2013	2,799	ebay.com
13.		Sony RX1R II	113 mm	65 mm	72 mm	507 g	220	n	Oct 2015	3,299	ebay.com
14.		Sony RX100 II	102 mm	58 mm	38 mm	281 g	350	n	Jun 2013	749	ebay.com
15.		Sony RX100 III	102 mm	58 mm	41 mm	290 g	320	n	May 2014	799	ebay.com
16.		Sony RX100 V	102 mm	58 mm	41 mm	299 g	220	n	Oct 2016	999	ebay.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

Any camera decision will obviously take relative prices into account. The listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The RX100 IV was launched at a lower price than the A7S, 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. Then, after the new model is out, very good deals can frequently be found on the pre-owned market.

Sensor comparison

The size of the imaging sensor is a crucial determinant of image quality. All other things equal, a large sensor will have larger individual pixel-units that offer better low-light sensitivity, wider dynamic range, and 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 tend to be associated with larger, more expensive camera bodies and lenses.

Of the two cameras under consideration, the Sony A7S features a full frame sensor and the Sony RX100 IV an one-inch sensor. The sensor area in the RX100 IV is 86 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.0 and 2.7. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

Despite having a smaller sensor, the RX100 IV offers a higher resolution of 20 megapixels, compared with 12 MP of the 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). However, it should be noted that the RX100 IV is a somewhat more recent model (by 1 year and 2 months) than the A7S, and its sensor might have benefitted from technological advances during this time that partly offset its pixel-size disadvantage.

The resolution advantage of the Sony RX100 IV implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the RX100 IV 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 Alpha A7S has a native sensitivity range from ISO 100 to ISO 102400, which can be extended to ISO 50-409600. The corresponding ISO settings for the Sony Cyber-shot DSC-RX100 IV are ISO 125 to ISO 12800, with the possibility to increase the ISO range to 80-25600.

In terms of underlying technology, the A7S is build around a CMOS sensor, while the RX100 IV uses a BSI-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.

For many cameras, data on sensor performance has been reported by DXO Mark. 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 A7S provides substantially higher image quality than the RX100 IV, with an overall score that is 17 points higher. This advantage is based on 1.1 bits higher color depth, 0.6 EV in additional dynamic range, and 2.6 stops in additional low light sensitivity. The table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar 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 A7S	Full Frame	12.0	4240	2832	1080/60p	23.9	13.2	3702	87
2.		Sony RX100 IV	1-inch	20.0	5472	3648	4K/30p	22.8	12.6	591	70
3.		Canon G5 X	1-inch	20.0	5472	3648	1080/60p	21.4	12.3	471	62
4.		Nikon Df	Full Frame	16.2	4928	3280	none	24.6	13.1	3279	89
5.		Panasonic FZ2500	1-inch	20.0	5472	3648	4K/30p	23.0	12.6	538	70
6.		Sony A7	Full Frame	24.0	6000	4000	1080/60p	24.8	14.2	2248	90
7.		Sony A7 II	Full Frame	24.0	6000	4000	1080/60p	24.9	13.6	2449	90
8.		Sony A7R	Full Frame	36.2	7360	4912	1080/60p	25.6	14.1	2746	95
9.		Sony A7R II	Full Frame	42.2	7952	5304	4K/30p	26.0	13.9	3434	98
10.		Sony A7S II	Full Frame	12.0	4240	2832	4K/30p	23.6	13.3	2993	85
11.		Sony RX1	Full Frame	24.0	6000	4000	1080/60p	25.1	14.3	2534	93
12.		Sony RX1R	Full Frame	24.0	6000	4000	1080/60p	25.0	13.6	2537	91
13.		Sony RX1R II	Full Frame	42.2	7952	5304	1080/60p	25.8	13.9	3204	97
14.		Sony RX100 II	1-inch	20.0	5472	3648	1080/60p	22.5	12.4	483	67
15.		Sony RX100 III	1-inch	20.0	5472	3648	1080/60p	22.4	12.3	495	67
16.		Sony RX100 V	1-inch	20.0	5472	3648	4K/30p	22.8	12.4	586	70
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 are not only capable of taking still images, but can also record movies. Both cameras under consideration are equipped with sensors that have a sufficiently high read-out speed for moving images, but the RX100 IV provides a better video resolution than the A7S. It can shoot movie footage at 4K/30p, while the A7S is limited to 1080/60p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a range of features. The two cameras under consideration are similar with respect to both having an electronic viewfinder. However, the one in the A7S offers a slightly higher resolution than the one in the RX100 IV (2400k vs 2359k dots). The adjacent table lists some of the other core features of the Sony A7S and Sony RX100 IV along with similar information for a selection of comparators.

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 A7S	2400	n	3.0 / 921	tilting	n	1/8000s	5.0/s	n	n
2.		Sony RX100 IV	2359	n	3.0 / 1228	tilting	n	1/2000s	16.0/s	Y	Y
3.		Canon G5 X	2360	n	3.0 / 1040	swivel	Y	1/2000s	5.9/s	Y	Y
4.		Nikon Df	optical	Y	3.2 / 921	fixed	n	1/4000s	5.5/s	n	n
5.		Panasonic FZ2500	2360	n	3.0 / 1040	swivel	Y	1/4000s	12.0/s	Y	Y
6.		Sony A7	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	n
7.		Sony A7 II	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	Y
8.		Sony A7R	2400	n	3.0 / 1230	tilting	n	1/8000s	4.0/s	n	n
9.		Sony A7R II	2400	n	3.0 / 1229	tilting	n	1/8000s	5.0/s	n	Y
10.		Sony A7S II	2400	n	3.0 / 1229	tilting	n	1/8000s	5.0/s	n	Y
11.		Sony RX1	optional	n	3.0 / 1229	fixed	n	1/4000s	5.0/s	Y	n
12.		Sony RX1R	optional	n	3.0 / 1229	fixed	n	1/4000s	5.0/s	Y	n
13.		Sony RX1R II	2360	n	3.0 / 1229	tilting	n	1/4000s	5.0/s	n	n
14.		Sony RX100 II	optional	n	3.0 / 1229	tilting	n	1/2000s	10.0/s	Y	Y
15.		Sony RX100 III	1440	n	3.0 / 1229	tilting	n	1/2000s	10.0/s	Y	Y
16.		Sony RX100 V	2359	n	3.0 / 1229	tilting	n	1/2000s	24.0/s	Y	Y
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 IV has one, while the A7S does not. While the built-in flash of the RX100 IV 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).

Concerning the storage of imaging data, both the A7S and the RX100 IV 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 Alpha A7S and Sony Cyber-shot DSC-RX100 IV 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 A7S	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
2.		Sony RX100 IV	-	stereo / mono	-	-	micro	2.0	Y	Y	-
3.		Canon G5 X	Y	stereo / mono	-	-	mini	2.0	Y	Y	-
4.		Nikon Df	Y	- / -	-	-	mini	2.0	-	-	-
5.		Panasonic FZ2500	Y	stereo / mono	Y	Y	micro	2.0	Y	-	-
6.		Sony A7	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
7.		Sony A7 II	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 A7R II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
10.		Sony A7S II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
11.		Sony RX1	Y	stereo / mono	Y	-	mini	2.0	-	-	-
12.		Sony RX1R	Y	stereo / mono	Y	-	mini	2.0	-	-	-
13.		Sony RX1R II	Y	stereo / mono	Y	-	micro	2.0	Y	Y	-
14.		Sony RX100 II	Y	stereo / mono	-	-	micro	2.0	Y	Y	-
15.		Sony RX100 III	-	stereo / mono	-	-	micro	2.0	Y	Y	-
16.		Sony RX100 V	-	stereo / mono	-	-	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 hotshoe, while the RX100 IV does not. This socket makes it possible to easily attach optional accessories, such as an external flash gun.

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

Review summary

So what is the bottom line? Is the Sony A7S better than the Sony RX100 IV or vice versa? Below is a summary of the relative strengths of each of the two contestants.

Arguments in favor of the Sony Alpha A7S:

• Better image quality: Scores substantially higher (17 points) in the DXO overall assessment.
• Richer colors: Generates images with noticeably better colors (1.1 bits more color depth).
• More dynamic range: Captures a larger spectrum of light and dark details (0.6 EV of extra DR).
• Better low-light sensitivity: Requires less light for good images (2.6 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.
• 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.
• More flexible: Accepts interchangeable lenses, so that lens characteristics can be altered.
• Longer lasting: Can take more shots (380 versus 280) on a single battery charge.
• Better sealing: Is weather sealed to enable shooting in dusty or wet environments.
• Better lighting: Features a hotshoe and can thus hold and trigger an external flash gun.
• More heavily discounted: Has been on the market for longer (launched in April 2014).

Advantages of the Sony Cyber-shot DSC-RX100 IV:

• More detail: Has more megapixels (20 vs 12MP), which boosts linear resolution by 29%.
• Better video: Provides higher definition movie capture (4K/30p vs 1080/60p).
• More detailed LCD: Has a higher resolution rear screen (1228k vs 921k dots).
• More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
• Faster burst: Shoots at higher frequency (16 vs 5 flaps/sec) to capture the decisive moment.
• Ready to shoot: Has an integrated lens, whereas the A7S necessitates an extra lens.
• More compact: Is smaller (102x58mm vs 127x94mm) and will fit more readily into a bag.
• Less heavy: Has a lower weight even though it has a lens built in (unlike the A7S).
• Sharper images: Has stabilization technology built-in to reduce the impact of hand-shake.
• Easier fill-in: Has a small integrated flash to brighten shadows of backlit subjects.
• More affordable: Was introduced at a lower price, despite coming with a built-in lens.
• More modern: Was introduced somewhat (1 year and 2 months) more recently.

If the number of relative strengths (bullet points above) is taken as a guide, the A7S comes out slightly ahead of the RX100 IV (13 : 12 points). However, the relative importance of the various individual camera aspects will vary according to personal preferences and needs, so that you might like to apply corresponding weights to the particular features before making a decision 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 A7S and the Sony RX100 IV place the cameras among the top in their class? Find out in the latest Best Mirrorless Interchangeable Lens Camera and Best Travel-Zoom 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 A7S or the RX100 IV. User reviews, such as those found at amazon, can sometimes inform about these issues, but such feedback is often incomplete, inconsistent, and biased.

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 A7S	4/5	..	..	86/100	4.5/5	5/5	Apr 2014	2,499	ebay.com
2.		Sony RX100 IV	4.5/5	+ +	..	85/100	4/5	4.5/5	Jun 2015	999	ebay.com
3.		Canon G5 X	5/5	+ +	..	78/100	4.5/5	4.5/5	Oct 2015	799	ebay.com
4.		Nikon Df	4/5	..	..	81/100	4/5	4/5	Nov 2013	2,749	ebay.com
5.		Panasonic FZ2500	..	+	..	82/100	4.5/5	5/5	Sep 2016	1,199	amazon.com
6.		Sony A7	5/5	+ +	..	80/100	5/5	5/5	Oct 2013	1,699	ebay.com
7.		Sony A7 II	5/5	+	4/5	82/100	4.5/5	5/5	Nov 2014	1,999	ebay.com
8.		Sony A7R	5/5	+ +	..	82/100	4.5/5	5/5	Oct 2013	2,299	ebay.com
9.		Sony A7R II	5/5	+ +	5/5	90/100	5/5	5/5	Jun 2015	3,199	ebay.com
10.		Sony A7S II	5/5	+	..	..	4.5/5	5/5	Sep 2015	2,999	ebay.com
11.		Sony RX1	5/5	..	..	79/100	4/5	4.5/5	Sep 2012	2,799	ebay.com
12.		Sony RX1R	5/5	..	..	..	4/5	4.5/5	Jun 2013	2,799	ebay.com
13.		Sony RX1R II	5/5	..	..	82/100	..	4.5/5	Oct 2015	3,299	ebay.com
14.		Sony RX100 II	5/5	+ +	..	79/100	4.5/5	4.5/5	Jun 2013	749	ebay.com
15.		Sony RX100 III	5/5	+ +	..	82/100	4.5/5	5/5	May 2014	799	ebay.com
16.		Sony RX100 V	4.5/5	+ +	..	83/100	4/5	4.5/5	Oct 2016	999	ebay.com
17.		Sony ZV-E1	..	+	4/5	..	..	4.5/5	Mar 2023	2,199	amazon.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The above review scores should be interpreted with care, though. The assessments were made in relation to similar cameras of the same technological generation. Thus, a score needs to be put into the context of the launch date and the launch price of the camera, and comparisons of ratings among very different cameras or across long time periods have little meaning. Also, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.

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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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