Nikon D3400 vs Sony A7

The Nikon D3400 and the Sony Alpha A7 are two digital cameras that were officially introduced, respectively, in August 2016 and October 2013. The D3400 is a DSLR, while the A7 is a mirrorless interchangeable lens camera. The cameras are based on an APS-C (D3400) and a full frame (A7) sensor. Both cameras offer a resolution of 24 megapixels.

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

Headline Specifications

Nikon D3400		Sony A7
Digital single lens reflex		Mirrorless system camera
Nikon F mount lenses		Sony E mount lenses
24 MP – APS-C sensor		24 MP – Full Frame sensor
1080/60p Video		1080/60p Video
ISO 100-25,600		ISO 100-25,600 (50 - 51,200)
Optical viewfinder		Electronic viewfinder (2400k dots)
3.0" LCD – 921k dots		3.0" LCD – 1230k dots
Fixed screen (not touch-sensitive)		Tilting screen (no touchscreen)
5 shutter flaps per second		5 shutter flaps per second
not weather sealed		Weathersealed body
1200 shots per battery charge		340 shots per battery charge
124 x 98 x 76 mm, 445 g		127 x 94 x 48 mm, 474 g

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Going beyond this snapshot of core features and characteristics, what are the differences between the Nikon D3400 and the Sony Alpha A7? 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 Nikon D3400 and the Sony A7. 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 size dimensions are rounded to the nearest millimeter.

The D3400 can be obtained in two different colors (black, red), while the A7 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 A7 is somewhat smaller (2 percent) than the Nikon D3400. However, the A7 is markedly heavier (7 percent) than the D3400. It is noteworthy in this context that the A7 is splash and dust-proof, while the D3400 does not feature any corresponding weather-sealing.

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. A larger imaging sensor will tend to go along with bigger and heavier lenses, although exceptions exist. You can compare the optics available for the two cameras in the Nikon Lens Catalog (D3400) and the Sony FE Lens Catalog (A7). Mirrorless cameras, such as the A7, have moreover the advantage that they can use many lenses from other systems via adapters, as they have a relatively short flange to focal plane distance.

Concerning battery life, the D3400 gets 1200 shots out of its EN-EL14a battery, while the A7 can take 340 images on a single charge of its NP-FW50 power pack. The power pack in the A7 can be charged via the USB port, 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. 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.		Nikon D3400	124 mm	98 mm	76 mm	445 g	1200	n	Aug 2016	499	ebay.com
2.		Sony A7	127 mm	94 mm	48 mm	474 g	340	Y	Oct 2013	1,699	ebay.com
3.		Canon SL2	122 mm	93 mm	70 mm	453 g	650	n	Jun 2017	549	ebay.com
4.		Nikon D3500	124 mm	97 mm	70 mm	415 g	1550	n	Aug 2018	429	amazon.com
5.		Nikon D5600	124 mm	97 mm	70 mm	465 g	970	n	Nov 2016	699	amazon.com
6.		Nikon D500	147 mm	115 mm	81 mm	860 g	1240	Y	Jan 2016	1,999	amazon.com
7.		Nikon D5500	124 mm	97 mm	70 mm	470 g	820	n	Jan 2015	899	ebay.com
8.		Nikon D7200	136 mm	107 mm	76 mm	765 g	1110	Y	Mar 2015	1,199	ebay.com
9.		Nikon D3300	124 mm	98 mm	76 mm	430 g	700	n	Jan 2014	499	ebay.com
10.		Nikon D5300	125 mm	98 mm	76 mm	480 g	600	n	Oct 2013	799	ebay.com
11.		Nikon D3200	125 mm	96 mm	77 mm	505 g	540	n	Apr 2012	599	ebay.com
12.		Nikon D5200	129 mm	98 mm	78 mm	555 g	500	n	Nov 2012	749	ebay.com
13.		Sony A7 II	127 mm	96 mm	60 mm	599 g	350	Y	Nov 2014	1,999	ebay.com
14.		Sony A7S	127 mm	94 mm	48 mm	489 g	380	Y	Apr 2014	2,499	ebay.com
15.		Sony A7R	127 mm	94 mm	48 mm	465 g	340	Y	Oct 2013	2,299	ebay.com
16.		Sony RX1R	113 mm	65 mm	70 mm	482 g	270	n	Jun 2013	2,799	ebay.com
17.		Sony RX1	113 mm	65 mm	70 mm	482 g	270	n	Sep 2012	2,799	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 listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The D3400 was launched at a markedly lower price (by 71 percent) than the A7, which puts it into a different market segment. 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 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 Nikon D3400 features an APS-C sensor and the Sony A7 a full frame sensor. The sensor area in the A7 is 133 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.

Even though the A7 has a larger sensor, both cameras offer the same resolution of 24 megapixels. This implies that the A7 has a lower pixel density and larger individual pixels (with a pixel pitch of 5.97μm versus 3.91μm for the D3400), which gives it a potential advantage in terms of light gathering capacity. It should, however, be noted that the D3400 is much more recent (by 2 years and 10 months) than the A7, and its sensor will have benefitted from technological advances during this time that at least partly compensate for the smaller pixel size. Coming back to sensor resolution, it should be mentioned that the D3400 has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

The A7 has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.

The Nikon D3400 has a native sensitivity range from ISO 100 to ISO 25600. The corresponding ISO settings for the Sony Alpha A7 are ISO 100 to ISO 25600, with the possibility to increase the ISO range to 50-51200.

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 consideration, the A7 has a markedly higher DXO score than the D3400 (overall score 4 points higher), which will translate into better image quality. 0.3 EV in additional dynamic range, and 0.9 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.		Nikon D3400	APS-C	24.0	6000	4000	1080/60p	24.8	13.9	1192	86
2.		Sony A7	Full Frame	24.0	6000	4000	1080/60p	24.8	14.2	2248	90
3.		Canon SL2	APS-C	24.0	6000	4000	1080/60p	23.6	13.4	1041	79
4.		Nikon D3500	APS-C	24.0	6000	4000	1080/60p	24.0	13.4	1851	83
5.		Nikon D5600	APS-C	24.0	6000	4000	1080/60p	24.1	14.0	1306	84
6.		Nikon D500	APS-C	20.7	5568	3712	4K/30p	24.0	14.0	1324	83
7.		Nikon D5500	APS-C	24.0	6000	4000	1080/60p	24.1	14.0	1438	84
8.		Nikon D7200	APS-C	24.0	6000	4000	1080/60p	24.5	14.6	1333	87
9.		Nikon D3300	APS-C	24.0	6000	4000	1080/60p	24.3	12.8	1385	82
10.		Nikon D5300	APS-C	24.0	6000	4000	1080/60p	24.0	13.9	1338	83
11.		Nikon D3200	APS-C	24.1	6016	4000	1080/30p	24.1	13.2	1131	81
12.		Nikon D5200	APS-C	24.0	6000	4000	1080/60i	24.2	13.9	1284	84
13.		Sony A7 II	Full Frame	24.0	6000	4000	1080/60p	24.9	13.6	2449	90
14.		Sony A7S	Full Frame	12.0	4240	2832	1080/60p	23.9	13.2	3702	87
15.		Sony A7R	Full Frame	36.2	7360	4912	1080/60p	25.6	14.1	2746	95
16.		Sony RX1R	Full Frame	24.0	6000	4000	1080/60p	25.0	13.6	2537	91
17.		Sony RX1	Full Frame	24.0	6000	4000	1080/60p	25.1	14.3	2534	93
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 have a sensor with sufficiently fast read-out times for 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. For example, the A7 has an electronic viewfinder (2400k dots), while the D3400 has an optical one. Both systems have their advantages, with the electronic viewfinder making it possible to project supplementary shooting information into the framing view, whereas the optical viewfinder offers lag-free viewing and a very clear framing image. The viewfinder in the A7 offers a wider field of view (100%) than the one in the D3400 (95%), so that a larger proportion of the captured image is visible in the finder. In addition, the viewfinder of the A7 has a higher magnification (0.71x vs 0.57x), so that the size of the image transmitted appears closer to the size seen with the naked human eye. The adjacent table lists some of the other core features of the Nikon D3400 and Sony A7 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.		Nikon D3400	optical	n	3.0 / 921	fixed	n	1/4000s	5.0/s	Y	n
2.		Sony A7	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	n
3.		Canon SL2	optical	n	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
4.		Nikon D3500	optical	n	3.0 / 921	fixed	n	1/4000s	5.0/s	Y	n
5.		Nikon D5600	optical	n	3.2 / 1037	swivel	Y	1/4000s	5.0/s	Y	n
6.		Nikon D500	optical	Y	3.2 / 2359	tilting	Y	1/8000s	10.0/s	n	n
7.		Nikon D5500	optical	n	3.2 / 1037	swivel	Y	1/4000s	5.0/s	Y	n
8.		Nikon D7200	optical	Y	3.2 / 1229	fixed	n	1/8000s	6.0/s	Y	n
9.		Nikon D3300	optical	n	3.0 / 921	fixed	n	1/4000s	5.0/s	Y	n
10.		Nikon D5300	optical	n	3.2 / 1037	swivel	n	1/4000s	5.0/s	Y	n
11.		Nikon D3200	optical	n	3.0 / 921	fixed	n	1/4000s	4.0/s	Y	n
12.		Nikon D5200	optical	n	3.0 / 921	swivel	n	1/4000s	5.0/s	Y	n
13.		Sony A7 II	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	Y
14.		Sony A7S	2400	n	3.0 / 921	tilting	n	1/8000s	5.0/s	n	n
15.		Sony A7R	2400	n	3.0 / 1230	tilting	n	1/8000s	4.0/s	n	n
16.		Sony RX1R	optional	n	3.0 / 1229	fixed	n	1/4000s	5.0/s	Y	n
17.		Sony RX1	optional	n	3.0 / 1229	fixed	n	1/4000s	5.0/s	Y	n
Notes: *) 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 D3400 has one, while the A7 does not. While the built-in flash of the D3400 is not very powerful, it can at times be useful as a fill-in light.

The D3400 writes its imaging data to SDXC cards, while the A7 uses 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 Nikon D3400 and Sony Alpha A7 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.		Nikon D3400	Y	mono / mono	-	-	mini	2.0	-	-	Y
2.		Sony A7	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
3.		Canon SL2	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
4.		Nikon D3500	Y	mono / mono	-	-	mini	2.0	-	-	Y
5.		Nikon D5600	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
6.		Nikon D500	Y	stereo / mono	Y	Y	mini	3.0	Y	Y	Y
7.		Nikon D5500	Y	stereo / mono	Y	-	mini	2.0	Y	-	-
8.		Nikon D7200	Y	stereo / mono	Y	Y	mini	2.0	Y	Y	-
9.		Nikon D3300	Y	mono / mono	Y	-	mini	2.0	-	-	-
10.		Nikon D5300	Y	stereo / mono	Y	-	mini	2.0	Y	-	-
11.		Nikon D3200	Y	mono / mono	Y	-	mini	2.0	-	-	-
12.		Nikon D5200	Y	stereo / mono	Y	-	mini	2.0	-	-	-
13.		Sony A7 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
14.		Sony A7S	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
15.		Sony A7R	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
16.		Sony RX1R	Y	stereo / mono	Y	-	mini	2.0	-	-	-
17.		Sony RX1	Y	stereo / mono	Y	-	mini	2.0	-	-	-

It is notable that the A7 offers wifi support, which can be a very convenient means to transfer image data to an off-camera location. In contrast, the D3400 does not provide wifi capability.

Both the D3400 and the A7 have been discontinued, but can regularly be found used on ebay. The A7 was replaced by the Sony A7 II, while the D3400 was followed by the Nikon D3500. Further information on the features and operation of the D3400 and A7 can be found, respectively, in the Nikon D3400 Manual (free pdf) or the online Sony A7 Manual.

Review summary

So how do things add up? Is there a clear favorite between the Nikon D3400 and the Sony A7? Which camera is better? A synthesis of the relative strong points of each of the models is listed below.

Advantages of the Nikon D3400:

• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• Brighter framing: Features an optical viewfinder for clear, lag-free composition.
• Longer lasting: Can take more shots (1200 versus 340) on a single battery charge.
• Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
• Easier wireless transfer: Supports Bluetooth for image sharing without cables.
• More affordable: Was introduced into a lower priced category (71 percent cheaper at launch).
• More modern: Reflects 2 years and 10 months of technical progress since the A7 launch.

Arguments in favor of the Sony Alpha A7:

• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• Better image quality: Scores markedly higher (4 points) in the DXO overall evaluation.
• Better low-light sensitivity: Can shoot in dim conditions (0.9 stops ISO advantage).
• Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
• 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 framing info: Has an electronic viewfinder that displays shooting data.
• More complete view: Has a viewfinder with a larger field of view (100% vs 95%).
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.71x vs 0.57x).
• More detailed LCD: Has a higher resolution rear screen (1230k vs 921k dots).
• More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
• Easier travel charging: Can be conveniently charged via its USB port.
• Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
• More legacy lens friendly: Can use many non-native lenses via adapters.
• 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.
• More heavily discounted: Has been around for much longer (launched in October 2013).

If the count of relative strengths (bullet points above) is taken as a measure, the A7 is the clear winner of the contest (18 : 7 points). However, the pertinence of the various camera strengths will differ across photographers, so that you might want to weigh individual camera traits according to their importance for your own imaging needs before making a camera decision. 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 Nikon D3400 and the Sony A7 place the cameras among the top in their class? Find out in the latest Best DSLR 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 D3400 or the A7. 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.		Nikon D3400	4/5	+	4/5	76/100	4/5	4.5/5	Aug 2016	499	ebay.com
2.		Sony A7	5/5	+ +	..	80/100	5/5	5/5	Oct 2013	1,699	ebay.com
3.		Canon SL2	4/5	+ +	4/5	78/100	4.5/5	4.5/5	Jun 2017	549	ebay.com
4.		Nikon D3500	4/5	..	4/5	75/100	4/5	4.5/5	Aug 2018	429	amazon.com
5.		Nikon D5600	4/5	..	4/5	79/100	4.5/5	4/5	Nov 2016	699	amazon.com
6.		Nikon D500	5/5	+ +	4.7/5	91/100	4.5/5	5/5	Jan 2016	1,999	amazon.com
7.		Nikon D5500	5/5	+	..	79/100	4.5/5	4.5/5	Jan 2015	899	ebay.com
8.		Nikon D7200	4/5	+ +	..	84/100	4.5/5	4.5/5	Mar 2015	1,199	ebay.com
9.		Nikon D3300	3/5	+	..	77/100	4.5/5	4.5/5	Jan 2014	499	ebay.com
10.		Nikon D5300	4/5	+ +	..	79/100	4.5/5	4.5/5	Oct 2013	799	ebay.com
11.		Nikon D3200	5/5	+ +	..	73/100	4.5/5	4.5/5	Apr 2012	599	ebay.com
12.		Nikon D5200	4/5	+ +	..	79/100	4.5/5	4.5/5	Nov 2012	749	ebay.com
13.		Sony A7 II	5/5	+	4/5	82/100	4.5/5	5/5	Nov 2014	1,999	ebay.com
14.		Sony A7S	4/5	..	..	86/100	4.5/5	5/5	Apr 2014	2,499	ebay.com
15.		Sony A7R	5/5	+ +	..	82/100	4.5/5	5/5	Oct 2013	2,299	ebay.com
16.		Sony RX1R	5/5	..	..	..	4/5	4.5/5	Jun 2013	2,799	ebay.com
17.		Sony RX1	5/5	..	..	79/100	4/5	4.5/5	Sep 2012	2,799	ebay.com
Notes: (+ +) 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? In case you would like to check on the differences and similarities of other camera models, just make your choice using the following search menu. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.

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