Sony RX100 II vs A5100

The Sony Cyber-shot DSC-RX100 II and the Sony Alpha A5100 are two digital cameras that were officially introduced, respectively, in June 2013 and August 2014. The RX100 II is a fixed lens compact, while the A5100 is a mirrorless interchangeable lens camera. The cameras are based on an one-inch (RX100 II) and an APS-C (A5100) sensor. The RX100 II has a resolution of 20 megapixels, whereas the A5100 provides 24 MP.

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

Headline Specifications

Sony RX100 II		Sony A5100
Fixed lens compact camera		Mirrorless system camera
28-100mm f/1.8-4.9		Sony E mount lenses
20 MP – 1" sensor		24 MP – APS-C sensor
1080/60p Video		1080/60p Video
ISO 100-12,800 (100 - 25,600)		ISO 100-25,600
Viewfinder optional		No viewfinder, LCD framing
3.0" LCD – 1229k dots		3.0" LCD – 922k dots
Tilting screen (no touchscreen)		Tilting touchscreen
10 shutter flaps per second		6 shutter flaps per second
350 shots per battery charge		400 shots per battery charge
102 x 58 x 38 mm, 281 g		110 x 63 x 36 mm, 283 g

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Going beyond this snapshot of core features and characteristics, what are the differences between the Sony Cyber-shot DSC-RX100 II and the Sony Alpha A5100? 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 RX100 II and the Sony A5100. The two cameras are presented according to their relative size. Three successive views from the front, the top, and the rear are shown. All size dimensions are rounded to the nearest millimeter.

The A5100 can be obtained in two different colors (black, white), while the RX100 II is only available in black.

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Sony A5100 is notably larger (17 percent) than the Sony RX100 II. In this context, it is worth noting that neither the RX100 II nor the A5100 are weather-sealed.

The above size and weight comparisons are to some extent incomplete and possibly misleading, as the RX100 II has a lens built in, whereas the A5100 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 A5100 and their specifications in the Sony E-Mount Lens Catalog.

Concerning battery life, the RX100 II gets 350 shots out of its Sony NP-BX1 battery, while the A5100 can take 400 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 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 RX100 II	102 mm	58 mm	38 mm	281 g	350	n	Jun 2013	749	ebay.com
2.		Sony A5100	110 mm	63 mm	36 mm	283 g	400	n	Aug 2014	549	ebay.com
3.		Canon G7 X	103 mm	60 mm	40 mm	304 g	210	n	Sep 2014	699	ebay.com
4.		Panasonic FZ1000	137 mm	99 mm	131 mm	831 g	360	n	Jun 2014	899	ebay.com
5.		Ricoh GR	117 mm	61 mm	35 mm	245 g	290	n	Apr 2013	799	ebay.com
6.		Sony A5000	110 mm	63 mm	36 mm	269 g	420	n	Jan 2014	449	ebay.com
7.		Sony A6000	120 mm	67 mm	45 mm	344 g	360	n	Feb 2014	599	ebay.com
8.		Sony NEX-3N	110 mm	62 mm	35 mm	269 g	480	n	Feb 2013	499	ebay.com
9.		Sony NEX-5R	111 mm	59 mm	39 mm	276 g	330	n	Aug 2012	749	ebay.com
10.		Sony RX100	102 mm	58 mm	36 mm	240 g	330	n	Jun 2012	649	ebay.com
11.		Sony RX100 III	102 mm	58 mm	41 mm	290 g	320	n	May 2014	799	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
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 manufacturer’s suggested retail prices give an idea on the placement of the camera in the maker’s lineup and the broader market. 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 imaging sensor is at the core of digital cameras and its size is one of the main determining factors 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. Further, a large sensor camera will give the photographer additional creative options when using shallow depth-of-field to isolate a subject from its 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 II features an one-inch sensor and the Sony A5100 an APS-C sensor. The sensor area in the A5100 is 216 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 2.7 and 1.5. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

With 24MP, the A5100 offers a higher resolution than the RX100 II (20MP), but the A5100 nevertheless has larger individual pixels (pixel pitch of 3.91μm versus 2.41μm for the RX100 II) due to its larger sensor. Moreover, the A5100 is a somewhat more recent model (by 1 year and 1 month) than the RX100 II, and its sensor might have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixel-units.

The resolution advantage of the Sony A5100 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A5100 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 RX100 II are 27.4 x 18.2 inches or 69.5 x 46.3 cm for good quality, 21.9 x 14.6 inches or 55.6 x 37.1 cm for very good quality, and 18.2 x 12.2 inches or 46.3 x 30.9 cm for excellent quality prints.

The A5100 has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.

The Sony Cyber-shot DSC-RX100 II has a native sensitivity range from ISO 100 to ISO 12800, which can be extended to ISO 100-25600. The corresponding ISO settings for the Sony Alpha A5100 are ISO 100 to ISO 25600 (no boost).

In terms of underlying technology, the RX100 II is build around a BSI-CMOS sensor, while the A5100 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.

For many cameras, data on sensor performance has been reported by DXO Mark. 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 A5100 offers substantially better image quality than the RX100 II (overall score 13 points higher). The advantage is based on 1.3 bits higher color depth, 0.3 EV in additional dynamic range, and 1.5 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 RX100 II	1-inch	20.0	5472	3648	1080/60p	22.5	12.4	483	67
2.		Sony A5100	APS-C	24.0	6000	4000	1080/60p	23.8	12.7	1347	80
3.		Canon G7 X	1-inch	20.0	5472	3648	1080/60p	23.0	12.7	556	71
4.		Panasonic FZ1000	1-inch	20.0	5472	3648	4K/30p	22.1	11.7	517	64
5.		Ricoh GR	APS-C	16.1	4928	3264	1080/30p	23.6	13.5	972	78
6.		Sony A5000	APS-C	19.8	5456	3632	1080/60i	23.8	13.0	1089	79
7.		Sony A6000	APS-C	24.0	6000	4000	1080/60p	24.1	13.1	1347	82
8.		Sony NEX-3N	APS-C	16.0	4912	3264	1080/60i	22.8	12.5	1067	74
9.		Sony NEX-5R	APS-C	16.0	4912	3264	1080/60i	23.7	13.1	910	78
10.		Sony RX100	1-inch	20.0	5472	3648	1080/60p	22.6	12.4	390	66
11.		Sony RX100 III	1-inch	20.0	5472	3648	1080/60p	22.4	12.3	495	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

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

Apart from body and sensor, cameras can and do differ across a range of features. The RX100 II and the A5100 are similar in the sense that neither of the two has a viewfinder. The images are, thus, framed using live view on the rear LCD. That said, the RX100 II can be equipped with an optional viewfinder – the FDA-EV1MK. The table below summarizes some of the other core capabilities of the Sony RX100 II and Sony A5100 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 II	optional	n	3.0 / 1229	tilting	n	1/2000s	10.0/s	Y	Y
2.		Sony A5100	none	n	3.0 / 922	tilting	Y	1/4000s	6.0/s	Y	n
3.		Canon G7 X	none	n	3.0 / 1040	tilting	Y	1/2000s	6.5/s	Y	Y
4.		Panasonic FZ1000	2359	n	3.0 / 921	swivel	n	1/4000s	12.0/s	Y	Y
5.		Ricoh GR	optional	n	3.0 / 1230	fixed	n	1/4000s	4.0/s	Y	n
6.		Sony A5000	none	n	3.0 / 461	tilting	n	1/4000s	3.5/s	Y	n
7.		Sony A6000	1440	n	3.0 / 922	tilting	n	1/4000s	11.0/s	Y	n
8.		Sony NEX-3N	optional	n	3.0 / 460	tilting	n	1/4000s	4.0/s	Y	n
9.		Sony NEX-5R	optional	n	3.0 / 920	tilting	Y	1/4000s	10.0/s	n	n
10.		Sony RX100	none	n	3.0 / 1229	fixed	n	1/2000s	10.0/s	Y	Y
11.		Sony RX100 III	1440	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
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One differentiating feature between the two cameras concerns the touch sensitivity of the rear screen. The A5100 has a touchscreen, while the RX100 II has a conventional panel. Touch control can be particularly helpful, for example, for setting the focus point.

Concerning the storage of imaging data, both the RX100 II and the A5100 write their files to SDXC or Memory Stick PRO Duo cards. The A5100 supports UHS-I cards (Ultra High Speed data transfer of up to 104 MB/s), while the RX100 II cannot take advantage of Ultra High Speed SD cards.

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 II and Sony Alpha A5100 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 II	Y	stereo / mono	-	-	micro	2.0	Y	Y	-
2.		Sony A5100	-	stereo / mono	-	-	micro	2.0	Y	Y	-
3.		Canon G7 X	-	stereo / mono	-	-	micro	2.0	Y	Y	-
4.		Panasonic FZ1000	Y	stereo / mono	Y	-	micro	2.0	Y	Y	-
5.		Ricoh GR	Y	mono / mono	-	-	micro	2.0	-	-	-
6.		Sony A5000	-	stereo / mono	-	-	micro	2.0	Y	Y	-
7.		Sony A6000	Y	stereo / mono	-	-	micro	2.0	Y	Y	-
8.		Sony NEX-3N	-	stereo / mono	-	-	micro	2.0	-	-	-
9.		Sony NEX-5R	Y	stereo / mono	-	-	mini	2.0	Y	-	-
10.		Sony RX100	-	stereo / mono	-	-	micro	2.0	-	-	-
11.		Sony RX100 III	-	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	-

It is notable that the RX100 II has a hotshoe, while the A5100 does not. This socket makes it possible to easily attach optional accessories, such as an external flash gun.

Both the RX100 II and the A5100 have been discontinued, but can regularly be found used on ebay. The RX100 II was replaced by the Sony RX100 III, while the A5100 does not have a direct successor. Further information on the features and operation of the RX100 II and A5100 can be found, respectively, in the Sony RX100 II Manual (free pdf) or the online Sony A5100 Manual.

Review summary

So what conclusions can be drawn? Is the Sony RX100 II better than the Sony A5100 or vice versa? The listing below highlights the relative strengths of the two models.

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

• More framing options: Can be equipped with a hotshoe-mounted accessory-viewfinder.
• More detailed LCD: Has a higher resolution rear screen (1229k vs 922k dots).
• Faster burst: Shoots at higher frequency (10 vs 6 flaps/sec) to capture the decisive moment.
• Ready to shoot: Has a lens built-in, whereas the A5100 requires a separate lens.
• More compact: Is smaller (102x58mm vs 110x63mm) and thus needs less room in the bag.
• Less heavy: Is lighter even though it comes with a built-in lens (unlike the A5100).
• Sharper images: Has hand-shake reducing image stabilization built-in.
• 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 June 2013).

Reasons to prefer the Sony Alpha A5100:

• More detail: Has more megapixels (24 vs 20MP), which boosts linear resolution by 10%.
• Better image quality: Scores substantially higher (13 points) in the DXO overall evaluation.
• Richer colors: Generates noticeably more natural colors (1.3 bits more color depth).
• Better low-light sensitivity: Can shoot in dim conditions (1.5 stops ISO advantage).
• Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
• Fewer buttons to press: Has a touchscreen to facilitate handling and shooting adjustments.
• More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
• Faster shutter: Has higher mechanical shutter speed (1/4000s vs 1/2000s) to freeze action.
• More flexible: Takes interchangeable lenses and can thus be used with specialty optics.
• Longer lasting: Gets more shots (400 versus 350) out of a single battery charge.
• Faster buffer clearing: Has an SD card interface that supports the UHS-I standard.
• More modern: Was introduced somewhat (1 year and 1 month) more recently.

If the number of relative strengths (bullet points above) is taken as a guide, the A5100 emerges as the winner of the match-up (12 : 9 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 wedding photographer will view the differences between cameras in a way that diverges from the perspective of a travel photog, and a person interested in cityscapes has distinct needs from a macro 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 II and the Sony A5100 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 technical specifications can provide a useful overview of the capabilities of different cameras, it remains incomplete and does no justice, for example, to the way the RX100 II or the A5100 perform in practice. 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 following table reports the overall ratings of the cameras as published by some of the major camera 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 II	5/5	+ +	..	79/100	4.5/5	4.5/5	Jun 2013	749	ebay.com
2.		Sony A5100	4.5/5	+	..	..	4.5/5	5/5	Aug 2014	549	ebay.com
3.		Canon G7 X	4/5	+ +	..	77/100	4.5/5	4.5/5	Sep 2014	699	ebay.com
4.		Panasonic FZ1000	4/5	+ +	..	82/100	4.5/5	4.5/5	Jun 2014	899	ebay.com
5.		Ricoh GR	5/5	..	..	79/100	4.5/5	4.5/5	Apr 2013	799	ebay.com
6.		Sony A5000	3/5	+	..	..	4.5/5	4.5/5	Jan 2014	449	ebay.com
7.		Sony A6000	5/5	+	4.5/5	80/100	4.5/5	5/5	Feb 2014	599	ebay.com
8.		Sony NEX-3N	3/5	..	..	..	4.5/5	4.5/5	Feb 2013	499	ebay.com
9.		Sony NEX-5R	..	..	..	..	4.5/5	4.5/5	Aug 2012	749	ebay.com
10.		Sony RX100	5/5	+ +	..	78/100	4/5	5/5	Jun 2012	649	ebay.com
11.		Sony RX100 III	5/5	+ +	..	82/100	4.5/5	5/5	May 2014	799	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
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The above review scores should be interpreted with care, though. The ratings are only valid when referring to cameras in the same category and of the same age. A score, therefore, has to be seen in close connection to the price and market introduction time of the camera, and comparisons of ratings among very different cameras or across long time periods 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

Did this review help to inform your camera decision process? If you would like to see a different side-by-side camera review, just use the search menu below. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.

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