Sony A5100 vs RX1R III

The Sony Alpha A5100 and the Sony Cyber-shot DSC-RX1R III are two digital cameras that were announced, respectively, in August 2014 and July 2025. The A5100 is a mirrorless interchangeable lens camera, while the RX1R III is a fixed lens compact. The cameras are based on an APS-C (A5100) and a full frame (RX1R III) sensor. The A5100 has a resolution of 24 megapixels, whereas the RX1R III provides 60.2 MP.

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

Headline Specifications

Sony A5100		Sony RX1R III
Mirrorless system camera		Fixed lens compact camera
Sony E mount lenses		35mm f/2.0
24 MP – APS-C sensor		60.2 MP – Full Frame sensor
1080/60p Video		4K/30p Video
ISO 100-25,600		ISO 100-32,000 (50 - 102,400)
No viewfinder, LCD framing		Electronic viewfinder (2360k dots)
3.0" LCD – 922k dots		3.0" LCD – 2360k dots
Tilting touchscreen		Fixed touchscreen
6 shutter flaps per second		5 shutter flaps per second
not weather sealed		Weathersealed body
400 shots per battery charge		300 shots per battery charge
110 x 63 x 36 mm, 283 g		113 x 68 x 88 mm, 498 g

Check A5100 offers at
ebay.com
Check RX1R III price at
amazon.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Sony Alpha A5100 and the Sony Cyber-shot DSC-RX1R III? 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 A5100 and the Sony RX1R III is provided 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 size dimensions are rounded to the nearest millimeter.

The A5100 can be obtained in two different colors (black, white), while the RX1R III 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 RX1R III is notably larger (11 percent) than the Sony A5100. It is noteworthy in this context that the RX1R III is splash and dust-proof, while the A5100 does not feature any corresponding weather-sealing.

The above size and weight comparisons are to some extent incomplete and possibly misleading, as the RX1R III 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.

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 want to switch the focus of the display and review another camera pair, you can move across to the CAM-parator tool and choose from the broad selection of possible camera comparisons there.

Body Specifications

		Camera Model	Camera Width	Camera Height	Camera Depth	Camera Weight	Battery Life	Weather Sealing	Camera Launch	Launch Price	Street Price
1.		Sony A5100	110 mm	63 mm	36 mm	283 g	400	n	Aug 2014	US$ 549	ebay.com
2.		Sony RX1R III	113 mm	68 mm	88 mm	498 g	300	Y	Jul 2025	US$ 5 099	amazon.com
3.		Leica Q3	130 mm	80 mm	93 mm	743 g	350	Y	May 2023	US$ 5 999	amazon.com
4.		Sony A7	127 mm	94 mm	48 mm	474 g	340	Y	Oct 2013	US$ 1 699	ebay.com
5.		Sony A7R	127 mm	94 mm	48 mm	465 g	340	Y	Oct 2013	US$ 2 299	ebay.com
6.		Sony A7S	127 mm	94 mm	48 mm	489 g	380	Y	Apr 2014	US$ 2 499	ebay.com
7.		Sony A3000	128 mm	91 mm	85 mm	411 g	470	n	Aug 2013	US$ 329	ebay.com
8.		Sony A5000	110 mm	63 mm	36 mm	269 g	420	n	Jan 2014	US$ 449	ebay.com
9.		Sony A6000	120 mm	67 mm	45 mm	344 g	360	n	Feb 2014	US$ 599	ebay.com
10.		Sony NEX-3	117 mm	62 mm	33 mm	297 g	330	n	May 2010	US$ 599	ebay.com
11.		Sony NEX-3N	110 mm	62 mm	35 mm	269 g	480	n	Feb 2013	US$ 499	ebay.com
12.		Sony NEX-5T	111 mm	59 mm	39 mm	276 g	330	n	Aug 2013	US$ 699	ebay.com
13.		Sony NEX-F3	117 mm	67 mm	42 mm	314 g	470	n	May 2012	US$ 599	ebay.com
14.		Sony RX1R II	113 mm	65 mm	72 mm	507 g	220	n	Oct 2015	US$ 3 299	ebay.com
15.		Sony RX100	102 mm	58 mm	36 mm	240 g	330	n	Jun 2012	US$ 649	ebay.com
16.		Sony RX100 II	102 mm	58 mm	38 mm	281 g	350	n	Jun 2013	US$ 749	ebay.com
17.		Sony RX100 IV	102 mm	58 mm	41 mm	298 g	280	n	Jun 2015	US$ 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 listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. 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 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 tend to be more expensive and lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the Sony A5100 features an APS-C sensor and the Sony RX1R III a full frame sensor. The sensor area in the RX1R III is 132 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.5 and 1.0. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

Technology-wise, the RX1R III uses a more advanced image processing engine (BIONZ XR) than the A5100 (BIONZ X), with benefits for noise reduction, color accuracy, and processing speed.

With 60.2MP, the RX1R III offers a higher resolution than the A5100 (24MP), but the RX1R III has smaller individual pixels (pixel pitch of 3.76μm versus 3.91μm for the A5100). Yet, the RX1R III is a much more recent model (by 10 years and 10 months) than the A5100, and its sensor will have benefitted from technological advances during this time that enhance the light gathering capacity of its pixel-units. Coming back to sensor resolution, it should be mentioned that the RX1R III has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

The resolution advantage of the Sony RX1R III implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the RX1R III for good quality output (200 dots per inch) amounts to 47.5 x 31.7 inches or 120.7 x 80.5 cm, for very good quality (250 dpi) 38 x 25.3 inches or 96.6 x 64.4 cm, and for excellent quality (300 dpi) 31.7 x 21.1 inches or 80.5 x 53.6 cm. The corresponding values for the Sony A5100 are 30 x 20 inches or 76.2 x 50.8 cm for good quality, 24 x 16 inches or 61 x 40.6 cm for very good quality, and 20 x 13.3 inches or 50.8 x 33.9 cm for excellent quality prints.

The Sony Alpha A5100 has a native sensitivity range from ISO 100 to ISO 25600. The corresponding ISO settings for the Sony Cyber-shot DSC-RX1R III are ISO 100 to ISO 32000, with the possibility to increase the ISO range to 50-102400.

In terms of underlying technology, the A5100 is build around a CMOS sensor, while the RX1R III 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 is based on lab testing and assigns an overall score to each camera sensor, as well as ratings for dynamic range ("DXO Landscape"), color depth ("DXO Portrait"), and low-light sensitivity ("DXO Sports"). 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 A5100	APS-C	24.0	6000	4000	1080/60p	23.8	12.7	1347	80
2.		Sony RX1R III	Full Frame	60.2	9504	6336	4K/30p	25.4	14.9	3417	97
3.		Leica Q3	Full Frame	60.3	9528	6328	8K/30p	25.4	14.7	3216	96
4.		Sony A7	Full Frame	24.0	6000	4000	1080/60p	24.8	14.2	2248	90
5.		Sony A7R	Full Frame	36.2	7360	4912	1080/60p	25.6	14.1	2746	95
6.		Sony A7S	Full Frame	12.0	4240	2832	1080/60p	23.9	13.2	3702	87
7.		Sony A3000	APS-C	19.8	5456	3632	1080/60i	23.7	12.8	1068	78
8.		Sony A5000	APS-C	19.8	5456	3632	1080/60i	23.8	13.0	1089	79
9.		Sony A6000	APS-C	24.0	6000	4000	1080/60p	24.1	13.1	1347	82
10.		Sony NEX-3	APS-C	14.0	4592	3056	720/30p	22.1	12.0	830	68
11.		Sony NEX-3N	APS-C	16.0	4912	3264	1080/60i	22.8	12.5	1067	74
12.		Sony NEX-5T	APS-C	16.0	4912	3264	1080/60p	23.6	13.0	1015	78
13.		Sony NEX-F3	APS-C	16.0	4912	3264	1080/60i	22.7	12.3	1114	73
14.		Sony RX1R II	Full Frame	42.2	7952	5304	1080/60p	25.8	13.9	3204	97
15.		Sony RX100	1-inch	20.0	5472	3648	1080/60p	22.6	12.4	390	66
16.		Sony RX100 II	1-inch	20.0	5472	3648	1080/60p	22.5	12.4	483	67
17.		Sony RX100 IV	1-inch	20.0	5472	3648	4K/30p	22.8	12.6	591	70
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. Both cameras under consideration are equipped with sensors that have a sufficiently high read-out speed for moving images, but the RX1R III provides a better video resolution than the A5100. It can shoot movie footage at 4K/30p, while the A5100 is limited to 1080/60p.

Feature comparison

Beyond body and sensor, cameras can and do differ across a range of features. For example, the RX1R III has an electronic viewfinder (2360k dots), which can be very helpful when shooting in bright sunlight. In contrast, the A5100 relies on live view and the rear LCD for framing. The adjacent table lists some of the other core features of the Sony A5100 and Sony RX1R III 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 A5100	none	n	3.0 / 922	tilting	Y	1/4000s	6.0/s	Y	n
2.		Sony RX1R III	2360	n	3.0 / 2360	fixed	Y	1/4000s	5.0/s	n	n
3.		Leica Q3	5760	n	3.0 / 1840	tilting	Y	1/2000s	15.0/s	n	Y
4.		Sony A7	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	n
5.		Sony A7R	2400	n	3.0 / 1230	tilting	n	1/8000s	4.0/s	n	n
6.		Sony A7S	2400	n	3.0 / 921	tilting	n	1/8000s	5.0/s	n	n
7.		Sony A3000	202	n	3.0 / 230	fixed	n	1/4000s	2.5/s	Y	n
8.		Sony A5000	none	n	3.0 / 461	tilting	n	1/4000s	3.5/s	Y	n
9.		Sony A6000	1440	n	3.0 / 922	tilting	n	1/4000s	11.0/s	Y	n
10.		Sony NEX-3	optional	n	3.0 / 920	tilting	n	1/4000s	7.0/s	n	n
11.		Sony NEX-3N	optional	n	3.0 / 460	tilting	n	1/4000s	4.0/s	Y	n
12.		Sony NEX-5T	optional	n	3.0 / 922	tilting	Y	1/4000s	10.0/s	n	n
13.		Sony NEX-F3	optional	n	3.0 / 920	tilting	n	1/4000s	5.5/s	Y	n
14.		Sony RX1R II	2360	n	3.0 / 1229	tilting	n	1/4000s	5.0/s	n	n
15.		Sony RX100	none	n	3.0 / 1229	fixed	n	1/2000s	10.0/s	Y	Y
16.		Sony RX100 II	optional	n	3.0 / 1229	tilting	n	1/2000s	10.0/s	Y	Y
17.		Sony RX100 IV	2359	n	3.0 / 1228	tilting	n	1/2000s	16.0/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 A5100 has one, while the RX1R III does not. While the built-in flash of the A5100 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 RX1R III 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).

The Sony RX1R III has an intervalometer built-in. This enables the photographer to capture time lapse sequences, such as flower blooming, a sunset or moon rise, without purchasing an external camera trigger and related software.

The A5100 writes its imaging data to SDXC or Memory Stick PRO Duo cards, while the RX1R III uses SDXC cards. The RX1R III supports UHS-II cards (Ultra High Speed data transfer of up to 312 MB/s), while the A5100 can use UHS-I cards (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 A5100 and Sony Cyber-shot DSC-RX1R III 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 A5100	-	stereo / mono	-	-	micro	2.0	Y	Y	-
2.		Sony RX1R III	Y	stereo / mono	Y	Y	micro	3.2	Y	-	Y
3.		Leica Q3	Y	stereo / mono	-	-	micro	3.1	Y	-	Y
4.		Sony A7	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
5.		Sony A7R	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
6.		Sony A7S	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
7.		Sony A3000	Y	stereo / mono	-	-	mini	2.0	-	-	-
8.		Sony A5000	-	stereo / mono	-	-	micro	2.0	Y	Y	-
9.		Sony A6000	Y	stereo / mono	-	-	micro	2.0	Y	Y	-
10.		Sony NEX-3	Y	stereo / mono	-	-	mini	2.0	-	-	-
11.		Sony NEX-3N	-	stereo / mono	-	-	micro	2.0	-	-	-
12.		Sony NEX-5T	Y	stereo / mono	-	-	mini	2.0	Y	Y	-
13.		Sony NEX-F3	Y	stereo / mono	-	-	mini	2.0	-	-	-
14.		Sony RX1R II	Y	stereo / mono	Y	-	micro	2.0	Y	Y	-
15.		Sony RX100	-	stereo / mono	-	-	micro	2.0	-	-	-
16.		Sony RX100 II	Y	stereo / mono	-	-	micro	2.0	Y	Y	-
17.		Sony RX100 IV	-	stereo / mono	-	-	micro	2.0	Y	Y	-

It is notable that the RX1R III has a microphone port, which can help to improve the quality of audio recordings by attaching an external microphone. The A5100 does not feature such a mic input.

The RX1R III is a recent model that features in the current product line-up of Sony. In contrast, the A5100 has been discontinued (but can be found pre-owned on ebay). There has not been a direct replacement model for the A5100 from Sony. Further information on the two cameras (e.g. user guides, manuals), as well as related accessories, can be found on the official Sony website.

Review summary

So how do things add up? Is there a clear favorite between the Sony A5100 and the Sony RX1R III? Which camera is better? Below is a summary of the relative strengths of each of the two contestants.

Advantages of the Sony Alpha A5100:

• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
• More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
• Faster burst: Shoots at higher frequency (6 vs 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 (400 versus 300) on a single battery charge.
• Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
• Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
• More heavily discounted: Has been available for much longer (launched in August 2014).

Arguments in favor of the Sony Cyber-shot DSC-RX1R III:

• More detail: Has more megapixels (60.2 vs 24MP), which boosts linear resolution by 58%.
• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• Better image quality: Is equipped with a larger and more technologically advanced sensor.
• Richer colors: The sensor size advantage translates into images with better, more accurate colors.
• More dynamic range: Larger sensor captures a wider spectrum of light and dark details.
• Better low-light sensitivity: Larger sensor produces good images even in poorly lit environments.
• Better jpgs: Has a more modern image processing engine (BIONZ XR vs BIONZ X).
• Better video: Provides higher definition movie capture (4K/30p vs 1080/60p).
• 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.
• Easier framing: Has an electronic viewfinder for image composition and settings control.
• More detailed LCD: Has a higher resolution rear screen (2360k vs 922k dots).
• Less disturbing: Has an electronic shutter option for completely silent shooting.
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• Ready to shoot: Has an integrated lens, whereas the A5100 necessitates an extra lens.
• 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.
• Faster data transfer: Supports a more advanced USB protocol (3.2 vs 2.0).
• Easier wireless transfer: Supports Bluetooth for image sharing without cables.
• Faster buffer clearing: Supports a more advanced SD data transfer standard (UHS-II vs UHS-I).
• More modern: Reflects 10 years and 10 months of technical progress since the A5100 launch.

If the number of relative strengths (bullet points above) is taken as a guide, the RX1R III is the clear winner of the contest (21 : 9 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 A5100 and the Sony RX1R III 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 says little about, for example, the shooting experience and imaging performance of the A5100 and the RX1R III in practical situations. 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	Street Price
1.		Sony A5100	4.5/5	+	..	..	4.5/5	5/5	Aug 2014	US$ 549	ebay.com
2.		Sony RX1R III	..	..	..	..	..	..	Jul 2025	US$ 5 099	amazon.com
3.		Leica Q3	5/5	..	4.5/5	..	..	4.5/5	May 2023	US$ 5 999	amazon.com
4.		Sony A7	5/5	+ +	..	80/100	5/5	5/5	Oct 2013	US$ 1 699	ebay.com
5.		Sony A7R	5/5	+ +	..	82/100	4.5/5	5/5	Oct 2013	US$ 2 299	ebay.com
6.		Sony A7S	4/5	..	..	86/100	4.5/5	5/5	Apr 2014	US$ 2 499	ebay.com
7.		Sony A3000	3/5	+	..	..	4/5	4/5	Aug 2013	US$ 329	ebay.com
8.		Sony A5000	3/5	+	..	..	4.5/5	4.5/5	Jan 2014	US$ 449	ebay.com
9.		Sony A6000	5/5	+	4.5/5	80/100	4.5/5	5/5	Feb 2014	US$ 599	ebay.com
10.		Sony NEX-3	..	..	..	70/100	4.5/5	4/5	May 2010	US$ 599	ebay.com
11.		Sony NEX-3N	3/5	..	..	..	4.5/5	4.5/5	Feb 2013	US$ 499	ebay.com
12.		Sony NEX-5T	..	..	..	..	4.5/5	4.5/5	Aug 2013	US$ 699	ebay.com
13.		Sony NEX-F3	4/5	..	..	74/100	4.5/5	4.5/5	May 2012	US$ 599	ebay.com
14.		Sony RX1R II	5/5	..	..	82/100	..	4.5/5	Oct 2015	US$ 3 299	ebay.com
15.		Sony RX100	5/5	+ +	..	78/100	4/5	5/5	Jun 2012	US$ 649	ebay.com
16.		Sony RX100 II	5/5	+ +	..	79/100	4.5/5	4.5/5	Jun 2013	US$ 749	ebay.com
17.		Sony RX100 IV	4.5/5	+ +	..	85/100	4/5	4.5/5	Jun 2015	US$ 999	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The review scores listed above should be treated with care, though. The ratings are only valid when referring to cameras in the same category and of the same age. Thus, a score needs to be put into the context of the launch date and the launch price of the camera, and rating-comparisons among cameras that span long time periods or concern very differently equipped models make little sense. 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

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