YI M1 vs Sony A7

The YI M1 and the Sony Alpha A7 are two digital cameras that were revealed to the public, respectively, in September 2016 and October 2013. Both the M1 and the A7 are mirrorless interchangeable lens cameras that are based on a Four Thirds (M1) and a full frame (A7) sensor. The YI has a resolution of 20.2 megapixels, whereas the Sony provides 24 MP.

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

Headline Specifications

YI M1		Sony A7
Mirrorless system camera		Mirrorless system camera
Micro Four Thirds lenses		Sony E mount lenses
20.2 MP – Four Thirds sensor		24 MP – Full Frame sensor
4K/30p Video		1080/60p Video
ISO 100-25,600		ISO 100-25,600 (50 - 51,200)
No viewfinder, LCD framing		Electronic viewfinder (2400k dots)
3.0" LCD – 1040k dots		3.0" LCD – 1230k dots
Fixed touchscreen		Tilting screen (no touchscreen)
5 shutter flaps per second		5 shutter flaps per second
not weather sealed		Weathersealed body
450 shots per battery charge		340 shots per battery charge
114 x 64 x 34 mm, 281 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 YI M1 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 YI M1 and the Sony A7. The two cameras are presented according to their relative size. Three consecutive perspectives from the front, the top, and the back are available. All width, height and depth dimensions are rounded to the nearest millimeter.

The M1 can be obtained in two different colors (black, silver), 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 considerably larger (64 percent) than the YI M1. Moreover, the A7 is substantially heavier (69 percent) than the M1. It is noteworthy in this context that the A7 is splash and dust-proof, while the M1 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 Micro Four Thirds Lens Catalog (M1) and the Sony FE Lens Catalog (A7). 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.

Concerning battery life, the M1 gets 450 shots out of its YI BXM-10 battery, while the A7 can take 340 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 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.		YI M1	114 mm	64 mm	34 mm	281 g	450	n	Sep 2016	349	ebay.com
2.		Sony A7	127 mm	94 mm	48 mm	474 g	340	Y	Oct 2013	1,699	ebay.com
3.		Canon SX420	104 mm	69 mm	85 mm	325 g	195	n	Jan 2016	299	ebay.com
4.		Canon SX430	104 mm	69 mm	85 mm	323 g	195	n	Jan 2017	299	ebay.com
5.		Canon SX710	113 mm	66 mm	35 mm	269 g	230	n	Jan 2015	349	ebay.com
6.		Canon SX720	110 mm	64 mm	36 mm	270 g	250	n	Feb 2016	379	ebay.com
7.		Canon SX730	110 mm	64 mm	40 mm	300 g	250	n	Apr 2017	399	ebay.com
8.		Fujifilm X-A3	117 mm	67 mm	40 mm	339 g	410	n	Aug 2016	399	ebay.com
9.		Nikon 1 J5	98 mm	60 mm	32 mm	231 g	250	n	Apr 2015	399	ebay.com
10.		Panasonic GF7	107 mm	65 mm	33 mm	266 g	230	n	Jan 2015	499	ebay.com
11.		Panasonic GX850	107 mm	65 mm	33 mm	269 g	210	n	Jan 2017	549	ebay.com
12.		Sony A7 II	127 mm	96 mm	60 mm	599 g	350	Y	Nov 2014	1,999	ebay.com
13.		Sony A7R	127 mm	94 mm	48 mm	465 g	340	Y	Oct 2013	2,299	ebay.com
14.		Sony A7S	127 mm	94 mm	48 mm	489 g	380	Y	Apr 2014	2,499	ebay.com
15.		Sony HX80	102 mm	58 mm	36 mm	245 g	390	n	Mar 2016	349	ebay.com
16.		Sony RX1	113 mm	65 mm	70 mm	482 g	270	n	Sep 2012	2,799	ebay.com
17.		Sony RX1R	113 mm	65 mm	70 mm	482 g	270	n	Jun 2013	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 manufacturer’s suggested retail prices give an idea on the placement of the camera in the maker’s lineup and the broader market. The M1 was launched at a markedly lower price (by 79 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 size of the sensor inside a digital camera is one of the key determinants 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. 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 are more costly to manufacture and tend to lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the YI M1 features a Four Thirds sensor and the Sony A7 a full frame sensor. The sensor area in the A7 is 280 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 2.0 and 1.0. The sensor in the M1 has a native 4:3 aspect ratio, while the one in the A7 offers a 3:2 aspect.

With 24MP, the A7 offers a higher resolution than the M1 (20.2MP), but the A7 nevertheless has larger individual pixels (pixel pitch of 5.97μm versus 3.34μm for the M1) due to its larger sensor. However, the M1 is a much more recent model (by 2 years and 11 months) than the A7, and its sensor will have benefitted from technological advances during this time that enhance the light gathering capacity of its pixel-units.

The resolution advantage of the Sony A7 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A7 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 YI M1 are 25.9 x 19.4 inches or 65.8 x 49.4 cm for good quality, 20.7 x 15.6 inches or 52.7 x 39.5 cm for very good quality, and 17.3 x 13 inches or 43.9 x 32.9 cm for excellent quality prints.

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

The YI M1 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.

Since 2007, DXO Mark has published sensor performance measurements that have been derived using a consistent methodology. 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.		YI M1	Four Thirds	20.2	5184	3888	4K/30p	23.0	12.6	1030	73
2.		Sony A7	Full Frame	24.0	6000	4000	1080/60p	24.8	14.2	2248	90
3.		Canon SX420	1/2.3	19.9	5152	3864	720/25p	20.3	11.7	806	48
4.		Canon SX430	1/2.3	19.9	5152	3864	720/25p	20.5	11.9	900	49
5.		Canon SX710	1/2.3	20.2	5184	3888	1080/60p	20.2	11.6	712	47
6.		Canon SX720	1/2.3	20.2	5184	3888	1080/60p	20.3	11.8	817	48
7.		Canon SX730	1/2.3	20.2	5184	3888	1080/60p	20.5	11.9	924	50
8.		Fujifilm X-A3	APS-C	24.0	6000	4000	1080/60p	23.8	13.1	1664	81
9.		Nikon 1 J5	1-inch	20.7	5568	3712	4K/15p	21.1	12.0	479	65
10.		Panasonic GF7	Four Thirds	15.8	4592	3448	1080/60p	22.7	12.3	874	70
11.		Panasonic GX850	Four Thirds	15.8	4592	3448	4K/30p	23.2	13.3	586	73
12.		Sony A7 II	Full Frame	24.0	6000	4000	1080/60p	24.9	13.6	2449	90
13.		Sony A7R	Full Frame	36.2	7360	4912	1080/60p	25.6	14.1	2746	95
14.		Sony A7S	Full Frame	12.0	4240	2832	1080/60p	23.9	13.2	3702	87
15.		Sony HX80	1/2.3	18.0	4896	3672	1080/60p	20.4	11.8	822	48
16.		Sony RX1	Full Frame	24.0	6000	4000	1080/60p	25.1	14.3	2534	93
17.		Sony RX1R	Full Frame	24.0	6000	4000	1080/60p	25.0	13.6	2537	91
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. The two cameras under consideration both have sensors whose read-out speed is fast enough to capture moving pictures, but the M1 provides a higher video resolution than the A7. It can shoot video footage at 4K/30p, while the Sony is limited to 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), which can be very helpful when shooting in bright sunlight. In contrast, the M1 relies on live view and the rear LCD for framing. The following table reports on some other key feature differences and similarities of the YI M1, the Sony A7, and comparable 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.		YI M1	none	n	3.0 / 1040	fixed	Y	1/4000s	5.0/s	n	n
2.		Sony A7	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	n
3.		Canon SX420	none	n	3.0 / 230	fixed	n	1/4000s	0.5/s	Y	Y
4.		Canon SX430	none	n	3.0 / 230	fixed	n	1/4000s	0.5/s	Y	Y
5.		Canon SX710	none	n	3.0 / 922	fixed	n	1/3200s	6.0/s	Y	Y
6.		Canon SX720	none	n	3.0 / 922	fixed	n	1/3200s	5.9/s	Y	Y
7.		Canon SX730	none	n	3.0 / 922	tilting	n	1/3200s	5.9/s	Y	Y
8.		Fujifilm X-A3	none	n	3.0 / 1040	tilting	Y	1/4000s	6.0/s	Y	n
9.		Nikon 1 J5	none	n	3.0 / 1037	tilting	Y	1/4000s	60.0/s	Y	n
10.		Panasonic GF7	none	n	3.0 / 1040	tilting	Y	1/500s	5.8/s	Y	n
11.		Panasonic GX850	none	n	3.0 / 1040	tilting	Y	1/500s	10.0/s	Y	n
12.		Sony A7 II	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	Y
13.		Sony A7R	2400	n	3.0 / 1230	tilting	n	1/8000s	4.0/s	n	n
14.		Sony A7S	2400	n	3.0 / 921	tilting	n	1/8000s	5.0/s	n	n
15.		Sony HX80	638	n	3.0 / 922	tilting	n	1/2000s	10.0/s	Y	Y
16.		Sony RX1	optional	n	3.0 / 1229	fixed	n	1/4000s	5.0/s	Y	n
17.		Sony RX1R	optional	n	3.0 / 1229	fixed	n	1/4000s	5.0/s	Y	n
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 M1 has a touchscreen, while the A7 has a conventional panel. Touch control can be particularly helpful, for example, for setting the focus point.

The YI M1 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 M1 writes its imaging data to SDXC cards, while the A7 uses SDXC or Memory Stick PRO Duo cards. The A7 supports UHS-I cards (Ultra High Speed data transfer of up to 104 MB/s), while the M1 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 YI M1 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.		YI M1	Y	stereo / mono	-	-	micro	2.0	Y	-	Y
2.		Sony A7	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
3.		Canon SX420	-	mono / mono	-	-	-	2.0	Y	Y	-
4.		Canon SX430	-	mono / mono	-	-	-	2.0	Y	Y	-
5.		Canon SX710	-	stereo / mono	-	-	micro	2.0	Y	Y	-
6.		Canon SX720	-	stereo / mono	-	-	micro	2.0	Y	Y	-
7.		Canon SX730	-	stereo / mono	-	-	micro	2.0	Y	Y	Y
8.		Fujifilm X-A3	Y	stereo / mono	-	-	micro	2.0	Y	-	-
9.		Nikon 1 J5	-	stereo / mono	-	-	micro	2.0	Y	Y	-
10.		Panasonic GF7	-	stereo / mono	-	-	micro	2.0	Y	Y	-
11.		Panasonic GX850	-	stereo / mono	-	-	micro	2.0	Y	-	-
12.		Sony A7 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
13.		Sony A7R	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 HX80	-	stereo / mono	-	-	micro	2.0	Y	Y	-
16.		Sony RX1	Y	stereo / mono	Y	-	mini	2.0	-	-	-
17.		Sony RX1R	Y	stereo / mono	Y	-	mini	2.0	-	-	-

It is notable that the A7 has a headphone jack, which makes it possible to attach external headphones and monitor the quality of sound during the recording process. The M1 lacks such a headphone port.

Both the M1 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 M1 does not have a direct successor. Further information on the features and operation of the M1 and A7 can be found, respectively, in the YI M1 Manual (free pdf) or the online Sony A7 Manual.

Review summary

So what is the bottom line? Is there a clear favorite between the YI M1 and the Sony A7? Which camera is better? Below is a summary of the relative strengths of each of the two contestants.

Reasons to prefer the YI M1:

• Better video: Provides higher definition movie capture (4K/30p vs 1080/60p).
• Fewer buttons to press: Is equipped with a touch-sensitive rear screen to facilitate handling.
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• More compact: Is smaller (114x64mm vs 127x94mm) and thus needs less room in the bag.
• Less heavy: Is lighter (by 193g or 41 percent) and hence easier to carry around.
• Longer lasting: Can take more shots (450 versus 340) on a single battery charge.
• Easier wireless transfer: Supports Bluetooth for image sharing without cables.
• More affordable: Was introduced into a lower priced category (79 percent cheaper at launch).
• More modern: Reflects 2 years and 11 months of technical progress since the A7 launch.

Arguments in favor of the Sony Alpha A7:

• More detail: Has more megapixels (24 vs 20.2MP), which boosts linear resolution by 11%.
• Better image quality: Features bigger pixels on a larger sensor for higher quality imaging.
• Richer colors: The pixel size advantage translates into images with better, more accurate colors.
• More dynamic range: Larger pixels capture a wider spectrum of light and dark details.
• Better low-light sensitivity: Larger pixels means good image quality even under poor lighting.
• 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.
• Easier framing: Has an electronic viewfinder for image composition and settings control.
• More detailed LCD: Has a higher resolution rear screen (1230k vs 1040k 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.
• Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
• 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 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 (16 : 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 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 YI M1 and the Sony A7 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 M1 or the A7 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.		YI M1	..	..	..	69/100	..	..	Sep 2016	349	ebay.com
2.		Sony A7	5/5	+ +	..	80/100	5/5	5/5	Oct 2013	1,699	ebay.com
3.		Canon SX420	..	..	..	..	..	3/5	Jan 2016	299	ebay.com
4.		Canon SX430	..	..	..	..	3.5/5	3.5/5	Jan 2017	299	ebay.com
5.		Canon SX710	..	+	..	..	4/5	3.5/5	Jan 2015	349	ebay.com
6.		Canon SX720	..	+	..	..	4/5	4.5/5	Feb 2016	379	ebay.com
7.		Canon SX730	..	+	..	..	4/5	4/5	Apr 2017	399	ebay.com
8.		Fujifilm X-A3	..	..	..	74/100	4.5/5	4/5	Aug 2016	399	ebay.com
9.		Nikon 1 J5	..	..	..	..	4.5/5	4.5/5	Apr 2015	399	ebay.com
10.		Panasonic GF7	4/5	+	..	..	4.5/5	4.5/5	Jan 2015	499	ebay.com
11.		Panasonic GX850	..	+	..	76/100	4.5/5	4.5/5	Jan 2017	549	ebay.com
12.		Sony A7 II	5/5	+	4/5	82/100	4.5/5	5/5	Nov 2014	1,999	ebay.com
13.		Sony A7R	5/5	+ +	..	82/100	4.5/5	5/5	Oct 2013	2,299	ebay.com
14.		Sony A7S	4/5	..	..	86/100	4.5/5	5/5	Apr 2014	2,499	ebay.com
15.		Sony HX80	..	..	..	..	..	..	Mar 2016	349	ebay.com
16.		Sony RX1	5/5	..	..	79/100	4/5	4.5/5	Sep 2012	2,799	ebay.com
17.		Sony RX1R	5/5	..	..	..	4/5	4.5/5	Jun 2013	2,799	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? In case you are interested in seeing how other cameras pair up, just make your choice using the following search menu. 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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