Sony A5100 vs NEX-3

The Sony Alpha A5100 and the Sony Alpha NEX-3 are two digital cameras that were announced, respectively, in August 2014 and May 2010. Both the A5100 and the NEX-3 are mirrorless interchangeable lens cameras that are equipped with an APS-C sensor. The A5100 has a resolution of 24 megapixels, whereas the NEX-3 provides 14 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 NEX-3
Mirrorless system camera		Mirrorless system camera
Sony E mount lenses		Sony E mount lenses
24 MP – APS-C sensor		14 MP – APS-C sensor
1080/60p Video		720/30p Video
ISO 100-25,600		ISO 200-12,800
No viewfinder, LCD framing		Viewfinder optional
3.0" LCD – 922k dots		3.0" LCD – 920k dots
Tilting touchscreen		Tilting screen (no touchscreen)
6 shutter flaps per second		7 shutter flaps per second
400 shots per battery charge		330 shots per battery charge
110 x 63 x 36 mm, 283 g		117 x 62 x 33 mm, 297 g

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Going beyond this snapshot of core features and characteristics, what are the differences between the Sony Alpha A5100 and the Sony Alpha NEX-3? 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 NEX-3 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 measures are rounded to the nearest millimeter.

The A5100 can be obtained in two different colors (black, white), while the NEX-3 is available in three color-versions (black, silver, red).

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Sony NEX-3 is somewhat larger (5 percent) than the Sony A5100. Moreover, the NEX-3 is markedly heavier (5 percent) than the A5100. In this context, it is worth noting that neither the A5100 nor the NEX-3 are weather-sealed.

The above size and weight comparisons are to some extent incomplete since they do not consider the interchangeable lenses that both of these cameras require. In this particular case, both cameras feature the same lens mount, so that they can use the same lenses. You can compare the optics available in the Sony E-Mount Lens Catalog. Mirrorless cameras, such as the two under consideration, have the additional advantage of having a short flange to focal plane distance, which makes it possible to mount many lenses from other systems onto the camera via adapters.

The power pack in the A5100 can be charged via the USB port, so that it is not always necessary to take the battery charger along 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 (USD)	Street Price
1.		Sony A5100	110 mm	63 mm	36 mm	283 g	400	n	Aug 2014	549	ebay.com
2.		Sony NEX-3	117 mm	62 mm	33 mm	297 g	330	n	May 2010	599	ebay.com
3.		Sony A3000	128 mm	91 mm	85 mm	411 g	470	n	Aug 2013	329	ebay.com
4.		Sony A5000	110 mm	63 mm	36 mm	269 g	420	n	Jan 2014	449	ebay.com
5.		Sony A6000	120 mm	67 mm	45 mm	344 g	360	n	Feb 2014	599	ebay.com
6.		Sony NEX-3N	110 mm	62 mm	35 mm	269 g	480	n	Feb 2013	499	ebay.com
7.		Sony NEX-5	111 mm	59 mm	38 mm	287 g	330	n	May 2010	699	ebay.com
8.		Sony NEX-5N	111 mm	59 mm	38 mm	269 g	460	n	Aug 2011	699	ebay.com
9.		Sony NEX-5R	111 mm	59 mm	39 mm	276 g	330	n	Aug 2012	749	ebay.com
10.		Sony NEX-5T	111 mm	59 mm	39 mm	276 g	330	n	Aug 2013	699	ebay.com
11.		Sony NEX-F3	117 mm	67 mm	42 mm	314 g	470	n	May 2012	599	ebay.com
12.		Sony RX100	102 mm	58 mm	36 mm	240 g	330	n	Jun 2012	649	ebay.com
13.		Sony RX100 II	102 mm	58 mm	38 mm	281 g	350	n	Jun 2013	749	ebay.com
14.		Sony RX100 IV	102 mm	58 mm	41 mm	298 g	280	n	Jun 2015	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

Any camera decision will obviously take relative prices into account. 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 A5100 was somewhat cheaper (by 8 percent) than the NEX-3 at launch, but both cameras fall into the same price category. 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. 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. 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. 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 associated with larger, more expensive camera bodies and lenses.

Both cameras under consideration feature an APS-C sensor, but their sensors differ slightly in size. The sensor area in the NEX-3 is 1 percent smaller. They nevertheless have the same format factor of 1.5. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

In terms of chip-set technology, the A5100 uses a more advanced image processing engine (BIONZ X) than the NEX-3 (BIONZ), with benefits for noise reduction, color accuracy, and processing speed.

With 24MP, the A5100 offers a higher resolution than the NEX-3 (14MP), but the A5100 has smaller individual pixels (pixel pitch of 3.91μm versus 5.11μm for the NEX-3). However, the A5100 is a much more recent model (by 4 years and 3 months) than the NEX-3, and its sensor will have benefitted from technological advances during this time that enhance the light gathering capacity of its pixels.

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 NEX-3 are 23 x 15.3 inches or 58.3 x 38.8 cm for good quality, 18.4 x 12.2 inches or 46.7 x 31 cm for very good quality, and 15.3 x 10.2 inches or 38.9 x 25.9 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 Alpha A5100 has a native sensitivity range from ISO 100 to ISO 25600. The corresponding ISO settings for the Sony Alpha NEX-3 are ISO 200 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.

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 A5100 provides substantially higher image quality than the NEX-3, with an overall score that is 12 points higher. This advantage is based on 1.7 bits higher color depth, 0.7 EV in additional dynamic range, and 0.7 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 A5100	APS-C	24.0	6000	4000	1080/60p	23.8	12.7	1347	80
2.		Sony NEX-3	APS-C	14.0	4592	3056	720/30p	22.1	12.0	830	68
3.		Sony A3000	APS-C	19.8	5456	3632	1080/60i	23.7	12.8	1068	78
4.		Sony A5000	APS-C	19.8	5456	3632	1080/60i	23.8	13.0	1089	79
5.		Sony A6000	APS-C	24.0	6000	4000	1080/60p	24.1	13.1	1347	82
6.		Sony NEX-3N	APS-C	16.0	4912	3264	1080/60i	22.8	12.5	1067	74
7.		Sony NEX-5	APS-C	14.0	4592	3056	1080/60i	22.2	12.2	796	69
8.		Sony NEX-5N	APS-C	16.0	4912	3264	1080/60i	23.6	12.7	1079	77
9.		Sony NEX-5R	APS-C	16.0	4912	3264	1080/60i	23.7	13.1	910	78
10.		Sony NEX-5T	APS-C	16.0	4912	3264	1080/60p	23.6	13.0	1015	78
11.		Sony NEX-F3	APS-C	16.0	4912	3264	1080/60i	22.7	12.3	1114	73
12.		Sony RX100	1-inch	20.0	5472	3648	1080/60p	22.6	12.4	390	66
13.		Sony RX100 II	1-inch	20.0	5472	3648	1080/60p	22.5	12.4	483	67
14.		Sony RX100 IV	1-inch	20.0	5472	3648	4K/30p	22.8	12.6	591	70

Many modern cameras are not only capable of taking still images, but can also record movies. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, but the A5100 provides a higher video resolution than the NEX-3. It can shoot video footage at 1080/60p, while the NEX-3 is limited to 720/30p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a range of features. The A5100 and the NEX-3 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 NEX-3 can be equipped with an optional viewfinder – the FDA-SV1. The table below summarizes some of the other core capabilities of the Sony A5100 and Sony NEX-3 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 A5100	none	n	3.0 / 922	tilting	Y	1/4000s	6.0/s	Y	n
2.		Sony NEX-3	optional	n	3.0 / 920	tilting	n	1/4000s	7.0/s	n	n
3.		Sony A3000	202	n	3.0 / 230	fixed	n	1/4000s	2.5/s	Y	n
4.		Sony A5000	none	n	3.0 / 461	tilting	n	1/4000s	3.5/s	Y	n
5.		Sony A6000	1440	n	3.0 / 922	tilting	n	1/4000s	11.0/s	Y	n
6.		Sony NEX-3N	optional	n	3.0 / 460	tilting	n	1/4000s	4.0/s	Y	n
7.		Sony NEX-5	optional	n	3.0 / 920	tilting	n	1/4000s	7.0/s	n	n
8.		Sony NEX-5N	optional	n	3.0 / 920	tilting	Y	1/4000s	10.0/s	n	n
9.		Sony NEX-5R	optional	n	3.0 / 920	tilting	Y	1/4000s	10.0/s	n	n
10.		Sony NEX-5T	optional	n	3.0 / 922	tilting	Y	1/4000s	10.0/s	n	n
11.		Sony NEX-F3	optional	n	3.0 / 920	tilting	n	1/4000s	5.5/s	Y	n
12.		Sony RX100	none	n	3.0 / 1229	fixed	n	1/2000s	10.0/s	Y	Y
13.		Sony RX100 II	optional	n	3.0 / 1229	tilting	n	1/2000s	10.0/s	Y	Y
14.		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 NEX-3 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.

Concerning the storage of imaging data, both the A5100 and the NEX-3 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 NEX-3 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 Alpha A5100 and Sony Alpha NEX-3 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 NEX-3	Y	stereo / mono	-	-	mini	2.0	-	-	-
3.		Sony A3000	Y	stereo / mono	-	-	mini	2.0	-	-	-
4.		Sony A5000	-	stereo / mono	-	-	micro	2.0	Y	Y	-
5.		Sony A6000	Y	stereo / mono	-	-	micro	2.0	Y	Y	-
6.		Sony NEX-3N	-	stereo / mono	-	-	micro	2.0	-	-	-
7.		Sony NEX-5	Y	stereo / mono	-	-	mini	2.0	-	-	-
8.		Sony NEX-5N	Y	stereo / mono	-	-	mini	2.0	-	-	-
9.		Sony NEX-5R	Y	stereo / mono	-	-	mini	2.0	Y	-	-
10.		Sony NEX-5T	Y	stereo / mono	-	-	mini	2.0	Y	Y	-
11.		Sony NEX-F3	Y	stereo / mono	-	-	mini	2.0	-	-	-
12.		Sony RX100	-	stereo / mono	-	-	micro	2.0	-	-	-
13.		Sony RX100 II	Y	stereo / mono	-	-	micro	2.0	Y	Y	-
14.		Sony RX100 IV	-	stereo / mono	-	-	micro	2.0	Y	Y	-

It is notable that the A5100 offers wifi support, while the NEX-3 does not. Wifi can be a very convenient means to transfer image data to an off-camera location.

Both the A5100 and the NEX-3 have been discontinued, but can regularly be found used on ebay. The NEX-3 was replaced by the Sony NEX-3N, while the A5100 does not have a direct successor. Further information on the features and operation of the A5100 and NEX-3 can be found, respectively, in the Sony A5100 Manual (free pdf) or the online Sony NEX-3 Manual.

Review summary

So what conclusions can be drawn? Is the Sony A5100 better than the Sony NEX-3 or vice versa? The listing below highlights the relative strengths of the two models.

Advantages of the Sony Alpha A5100:

• More detail: Offers more megapixels (24 vs 14MP) with a 31% higher linear resolution.
• Better image quality: Scores substantially higher (12 points) in the DXO overall assessment.
• Richer colors: Generates images with noticeably better colors (1.7 bits more color depth).
• More dynamic range: Captures a larger spectrum of light and dark details (0.7 EV of extra DR).
• Better low-light sensitivity: Requires less light for good images (0.7 stops ISO advantage).
• Better jpgs: Has a more modern image processing engine (BIONZ X vs BIONZ).
• Better video: Provides higher definition movie capture (1080/60p vs 720/30p).
• Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
• Fewer buttons to press: Is equipped with a touch-sensitive rear screen to facilitate handling.
• Longer lasting: Can take more shots (400 versus 330) on a single battery charge.
• Easier travel charging: Can be conveniently charged via its USB port.
• Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
• Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
• Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
• Faster buffer clearing: Has an SD card interface that supports the UHS-I standard.
• More modern: Reflects 4 years and 3 months of technical progress since the NEX-3 launch.

Reasons to prefer the Sony Alpha NEX-3:

• More framing options: Can be equipped with a hotshoe-mounted accessory-viewfinder.
• Faster burst: Shoots at higher frequency (7 vs 6 flaps/sec) to capture the decisive moment.
• Better lighting: Features a hotshoe and can thus hold and trigger an external flash gun.
• More heavily discounted: Has been around for much longer (launched in May 2010).

If the number of relative strengths (bullet points above) is taken as a guide, the A5100 is the clear winner of the match-up (16 : 4 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 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 A5100 and the Sony NEX-3 place the cameras among the top in their class? Find out in the latest Best Mirrorless Interchangeable Lens Camera listing 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 A5100 or the NEX-3 perform in practice. User reviews that are available, for instance, at amazon can sometimes shed light on these issues, but such feedback is all too often partial, inconsistent, and inaccurate.

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 A5100	4.5/5	+	..	..	4.5/5	5/5	Aug 2014	549	ebay.com
2.		Sony NEX-3	..	..	..	70/100	4.5/5	4/5	May 2010	599	ebay.com
3.		Sony A3000	3/5	+	..	..	4/5	4/5	Aug 2013	329	ebay.com
4.		Sony A5000	3/5	+	..	..	4.5/5	4.5/5	Jan 2014	449	ebay.com
5.		Sony A6000	5/5	+	4.5/5	80/100	4.5/5	5/5	Feb 2014	599	ebay.com
6.		Sony NEX-3N	3/5	..	..	..	4.5/5	4.5/5	Feb 2013	499	ebay.com
7.		Sony NEX-5	3/5	+ +	..	71/100	4.5/5	4/5	May 2010	699	ebay.com
8.		Sony NEX-5N	3/5	+ +	..	79/100	4.5/5	4.5/5	Aug 2011	699	ebay.com
9.		Sony NEX-5R	..	..	..	..	4.5/5	4.5/5	Aug 2012	749	ebay.com
10.		Sony NEX-5T	..	..	..	..	4.5/5	4.5/5	Aug 2013	699	ebay.com
11.		Sony NEX-F3	4/5	..	..	74/100	4.5/5	4.5/5	May 2012	599	ebay.com
12.		Sony RX100	5/5	+ +	..	78/100	4/5	5/5	Jun 2012	649	ebay.com
13.		Sony RX100 II	5/5	+ +	..	79/100	4.5/5	4.5/5	Jun 2013	749	ebay.com
14.		Sony RX100 IV	4.5/5	+ +	..	85/100	4/5	4.5/5	Jun 2015	999	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The review scores listed above should be treated with care, though. The assessments were made in relation to similar cameras of the same technological generation. 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. 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 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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