Sony A77 II vs YI M1

The Sony Alpha SLT-A77 II and the YI M1 are two digital cameras that were announced, respectively, in May 2014 and September 2016. The A77 II is a DSLR, while the M1 is a mirrorless interchangeable lens camera. The cameras are based on an APS-C (A77 II) and a Four Thirds (M1) sensor. The Sony has a resolution of 24 megapixels, whereas the YI provides 20.2 MP.

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

Headline Specifications

Sony A77 II		YI M1
Digital single lens reflex		Mirrorless system camera
Sony A mount lenses		Micro Four Thirds lenses
24 MP – APS-C sensor		20.2 MP – Four Thirds sensor
1080/60p Video		4K/30p Video
ISO 100-25,600 (50 - 51,200)		ISO 100-25,600
Electronic viewfinder (2359k dots)		No viewfinder, LCD framing
3.0" LCD – 1229k dots		3.0" LCD – 1040k dots
Fully flexible screen (no touchscreen)		Fixed touchscreen
12 shutter flaps per second		5 shutter flaps per second
In-body stabilization		Lens stabilization only
Weathersealed body		not weather sealed
480 shots per battery charge		450 shots per battery charge
143 x 104 x 81 mm, 647 g		114 x 64 x 34 mm, 281 g

Check A77 II offers at
ebay.com
Check M1 offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Sony Alpha SLT-A77 II and the YI M1? 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 physical size and weight of the Sony A77 II and the YI M1 are illustrated in the side-by-side display below. The two cameras are presented according to their relative size. Three consecutive perspectives from the front, the top, and the back are available. All size dimensions are rounded to the nearest millimeter.

The M1 can be obtained in two different colors (black, silver), while the A77 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 YI M1 is considerably smaller (51 percent) than the Sony A77 II. Moreover, the M1 is substantially lighter (57 percent) than the A77 II. It is worth mentioning in this context that the A77 II is splash and dust resistant, 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. Hence, you might want to study and compare the specifications of available lenses in order to get the full picture of the size and weight of the two camera systems.

Concerning battery life, the A77 II gets 480 shots out of its Sony NP-FM500H battery, while the M1 can take 450 images on a single charge of its YI BXM-10 power pack. The power pack in the M1 can be charged via the USB port, which can be very convenient when travelling.

The table below summarizes the key physical specs of the two cameras alongside a broader set of comparators. 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 A77 II	143 mm	104 mm	81 mm	647 g	480	Y	May 2014	1,199	ebay.com
2.		YI M1	114 mm	64 mm	34 mm	281 g	450	n	Sep 2016	349	ebay.com
3.		Canon SX730	110 mm	64 mm	40 mm	300 g	250	n	Apr 2017	399	ebay.com
4.		Fujifilm X-A3	117 mm	67 mm	40 mm	339 g	410	n	Aug 2016	399	ebay.com
5.		Nikon 1 J5	98 mm	60 mm	32 mm	231 g	250	n	Apr 2015	399	ebay.com
6.		Nikon D7100	136 mm	107 mm	76 mm	765 g	950	Y	Feb 2013	1,199	ebay.com
7.		Nikon D7200	136 mm	107 mm	76 mm	765 g	1110	Y	Mar 2015	1,199	ebay.com
8.		Panasonic GF7	107 mm	65 mm	33 mm	266 g	230	n	Jan 2015	499	ebay.com
9.		Panasonic GX850	107 mm	65 mm	33 mm	269 g	210	n	Jan 2017	549	ebay.com
10.		Pentax K-3	131 mm	100 mm	77 mm	800 g	560	Y	Oct 2013	1,299	ebay.com
11.		Pentax K-3 II	131 mm	100 mm	77 mm	800 g	720	Y	Apr 2015	1,099	ebay.com
12.		Sony A7 II	127 mm	96 mm	60 mm	599 g	350	Y	Nov 2014	1,999	ebay.com
13.		Sony A58	129 mm	95 mm	78 mm	492 g	690	n	Feb 2013	599	ebay.com
14.		Sony A68	143 mm	104 mm	81 mm	610 g	540	n	Nov 2015	699	ebay.com
15.		Sony A77	143 mm	104 mm	81 mm	732 g	470	Y	Aug 2011	1,399	ebay.com
16.		Sony A6500	120 mm	67 mm	53 mm	453 g	350	Y	Oct 2016	1,399	ebay.com
17.		Sony A6600	120 mm	67 mm	69 mm	503 g	810	Y	Aug 2019	1,399	amazon.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 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 M1 was launched at a markedly lower price (by 71 percent) than the A77 II, 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. 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 associated with larger, more expensive camera bodies and lenses.

Of the two cameras under consideration, the Sony A77 II features an APS-C sensor and the YI M1 a Four Thirds sensor. The sensor area in the M1 is 39 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.5 and 2.0. The sensor in the A77 II has a native 3:2 aspect ratio, while the one in the M1 offers a 4:3 aspect.

With 24MP, the A77 II offers a higher resolution than the M1 (20.2MP), but the A77 II nevertheless has larger individual pixels (pixel pitch of 3.91μm versus 3.34μm for the M1) due to its larger sensor. However, the M1 is a much more recent model (by 2 years and 4 months) than the A77 II, and its sensor will have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixels.

The resolution advantage of the Sony A77 II implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A77 II 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 Sony Alpha SLT-A77 II has a native sensitivity range from ISO 100 to ISO 25600, which can be extended to ISO 50-51200. The corresponding ISO settings for the YI M1 are ISO 100 to ISO 25600 (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.

Since 2007, DXO Mark has published sensor performance measurements that have been derived using a consistent methodology. 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. 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 A77 II	APS-C	24.0	6000	4000	1080/60p	24.4	13.4	1013	82
2.		YI M1	Four Thirds	20.2	5184	3888	4K/30p	23.0	12.6	1030	73
3.		Canon SX730	1/2.3	20.2	5184	3888	1080/60p	20.5	11.9	924	50
4.		Fujifilm X-A3	APS-C	24.0	6000	4000	1080/60p	23.8	13.1	1664	81
5.		Nikon 1 J5	1-inch	20.7	5568	3712	4K/15p	21.1	12.0	479	65
6.		Nikon D7100	APS-C	24.0	6000	4000	1080/60p	24.2	13.7	1256	83
7.		Nikon D7200	APS-C	24.0	6000	4000	1080/60p	24.5	14.6	1333	87
8.		Panasonic GF7	Four Thirds	15.8	4592	3448	1080/60p	22.7	12.3	874	70
9.		Panasonic GX850	Four Thirds	15.8	4592	3448	4K/30p	23.2	13.3	586	73
10.		Pentax K-3	APS-C	24.1	6016	4000	1080/60i	23.7	13.4	1216	80
11.		Pentax K-3 II	APS-C	24.1	6016	4000	1080/60i	23.6	13.6	1106	80
12.		Sony A7 II	Full Frame	24.0	6000	4000	1080/60p	24.9	13.6	2449	90
13.		Sony A58	APS-C	19.8	5456	3632	1080/60i	23.3	12.5	753	74
14.		Sony A68	APS-C	24.0	6000	4000	1080/60i	24.1	13.5	701	79
15.		Sony A77	APS-C	24.0	6000	4000	1080/60p	24.0	13.2	801	78
16.		Sony A6500	APS-C	24.0	6000	4000	4K/30p	24.5	13.7	1405	85
17.		Sony A6600	APS-C	24.0	6000	4000	4K/30p	23.8	13.4	1497	82
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 better video resolution than the A77 II. It can shoot movie 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 variety of features. For example, the A77 II has an electronic viewfinder (2359k 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 adjacent table lists some of the other core features of the Sony A77 II and YI M1 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 A77 II	2359	Y	3.0 / 1229	full-flex	n	1/8000s	12.0/s	Y	Y
2.		YI M1	none	n	3.0 / 1040	fixed	Y	1/4000s	5.0/s	n	n
3.		Canon SX730	none	n	3.0 / 922	tilting	n	1/3200s	5.9/s	Y	Y
4.		Fujifilm X-A3	none	n	3.0 / 1040	tilting	Y	1/4000s	6.0/s	Y	n
5.		Nikon 1 J5	none	n	3.0 / 1037	tilting	Y	1/4000s	60.0/s	Y	n
6.		Nikon D7100	optical	Y	3.2 / 1229	fixed	n	1/8000s	6.0/s	Y	n
7.		Nikon D7200	optical	Y	3.2 / 1229	fixed	n	1/8000s	6.0/s	Y	n
8.		Panasonic GF7	none	n	3.0 / 1040	tilting	Y	1/500s	5.8/s	Y	n
9.		Panasonic GX850	none	n	3.0 / 1040	tilting	Y	1/500s	10.0/s	Y	n
10.		Pentax K-3	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	Y	Y
11.		Pentax K-3 II	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	n	Y
12.		Sony A7 II	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	Y
13.		Sony A58	1440	n	2.7 / 460	tilting	n	1/4000s	5.0/s	Y	Y
14.		Sony A68	1440	Y	2.7 / 460	tilting	n	1/4000s	8.0/s	Y	Y
15.		Sony A77	2359	Y	3.0 / 921	full-flex	n	1/8000s	12.0/s	Y	Y
16.		Sony A6500	2359	n	3.0 / 922	tilting	Y	1/4000s	11.0/s	Y	Y
17.		Sony A6600	2359	n	3.0 / 922	tilting	Y	1/4000s	11.0/s	n	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 A77 II has one, while the M1 does not. While the built-in flash of the A77 II is not very powerful, it can at times be useful as a fill-in light.

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 A77 II writes its imaging data to SDXC or Memory Stick PRO Duo cards, while the M1 uses SDXC cards. The A77 II 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 Sony Alpha SLT-A77 II and YI M1 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 A77 II	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
2.		YI M1	Y	stereo / mono	-	-	micro	2.0	Y	-	Y
3.		Canon SX730	-	stereo / mono	-	-	micro	2.0	Y	Y	Y
4.		Fujifilm X-A3	Y	stereo / mono	-	-	micro	2.0	Y	-	-
5.		Nikon 1 J5	-	stereo / mono	-	-	micro	2.0	Y	Y	-
6.		Nikon D7100	Y	stereo / mono	Y	Y	mini	2.0	-	-	-
7.		Nikon D7200	Y	stereo / mono	Y	Y	mini	2.0	Y	Y	-
8.		Panasonic GF7	-	stereo / mono	-	-	micro	2.0	Y	Y	-
9.		Panasonic GX850	-	stereo / mono	-	-	micro	2.0	Y	-	-
10.		Pentax K-3	Y	mono / mono	Y	Y	mini	3.0	-	-	-
11.		Pentax K-3 II	Y	mono / mono	Y	Y	mini	3.0	-	-	-
12.		Sony A7 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
13.		Sony A58	Y	stereo / mono	Y	-	mini	2.0	-	-	-
14.		Sony A68	Y	stereo / mono	Y	-	micro	2.0	-	-	-
15.		Sony A77	Y	stereo / mono	Y	-	mini	2.0	-	-	-
16.		Sony A6500	Y	stereo / mono	Y	-	micro	2.0	Y	Y	-
17.		Sony A6600	Y	stereo / mono	Y	Y	YES	2.0	Y	Y	Y

It is notable that the A77 II has a microphone port, which is missing on the M1. Such an external microphone input can help to substantially improve the quality of audio recordings when a good external microphone is used.

Studio photographers will appreciate that the Sony A77 II (unlike the M1) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

Both the A77 II and the M1 have been discontinued, but can regularly be found used on ebay. Neither of the two has a direct successor, so they represent the end of the respective camera lines from Sony and YI. Further information on the features and operation of the A77 II and M1 can be found, respectively, in the Sony A77 II Manual (free pdf) or the online YI M1 Manual.

Review summary

So what conclusions can be drawn? Is there a clear favorite between the Sony A77 II and the YI M1? Which camera is better? Below is a summary of the relative strengths of each of the two contestants.

Arguments in favor of the Sony Alpha SLT-A77 II:

• More detail: Offers more megapixels (24 vs 20.2MP) with a 11% higher linear resolution.
• 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 sound: Can connect to an external microphone for higher quality sound recording.
• Easier framing: Has an electronic viewfinder for image composition and settings control.
• Easier setting verification: Features an LCD display on top to control shooting parameters.
• More detailed LCD: Has a higher resolution rear screen (1229k vs 1040k dots).
• More flexible LCD: Has a full-flex screen for odd-angle shots in portrait or landscape orientation.
• More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
• Faster burst: Shoots at higher frequency (12 vs 5 flaps/sec) to capture the decisive moment.
• Better sealing: Is weather sealed to enable shooting in dusty or wet environments.
• Sharper images: Has hand-shake reducing image stabilization built-in.
• 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.
• Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
• Faster buffer clearing: Has an SD card interface that supports the UHS-I standard.
• More heavily discounted: Has been available for much longer (launched in May 2014).

Advantages of the YI M1:

• Better video: Provides higher definition movie capture (4K/30p vs 1080/60p).
• Fewer buttons to press: Has a touchscreen to facilitate handling and shooting adjustments.
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• More compact: Is smaller (114x64mm vs 143x104mm) and will fit more readily into a bag.
• Less heavy: Has a lower weight (by 366g or 57 percent) and is thus easier to take along.
• Easier travel charging: Can be conveniently charged via its USB port.
• More legacy lens friendly: Can use many non-native lenses via adapters.
• 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 4 months of technical progress since the A77 II launch.

If the count of individual advantages (bullet points above) is taken as a guide, the A77 II is the clear winner of the match-up (20 : 10 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 sports photographer will view the differences between cameras in a way that diverges from the perspective of a street photog, and a person interested in family portraits has distinct needs from a landscape 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 A77 II and the YI M1 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 says little about, for example, the shooting experience and imaging performance of the A77 II and the M1 in practical situations. 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 where reviews by experts come in. The adjacent summary-table relays the overall verdicts of several of the most popular 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 A77 II	4/5	..	..	80/100	4.5/5	5/5	May 2014	1,199	ebay.com
2.		YI M1	..	..	..	69/100	..	..	Sep 2016	349	ebay.com
3.		Canon SX730	..	+	..	..	4/5	4/5	Apr 2017	399	ebay.com
4.		Fujifilm X-A3	..	..	..	74/100	4.5/5	4/5	Aug 2016	399	ebay.com
5.		Nikon 1 J5	..	..	..	..	4.5/5	4.5/5	Apr 2015	399	ebay.com
6.		Nikon D7100	5/5	+ +	..	85/100	4.5/5	4.5/5	Feb 2013	1,199	ebay.com
7.		Nikon D7200	4/5	+ +	..	84/100	4.5/5	4.5/5	Mar 2015	1,199	ebay.com
8.		Panasonic GF7	4/5	+	..	..	4.5/5	4.5/5	Jan 2015	499	ebay.com
9.		Panasonic GX850	..	+	..	76/100	4.5/5	4.5/5	Jan 2017	549	ebay.com
10.		Pentax K-3	4/5	..	..	83/100	5/5	5/5	Oct 2013	1,299	ebay.com
11.		Pentax K-3 II	4.5/5	..	..	..	5/5	5/5	Apr 2015	1,099	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 A58	3/5	..	..	..	4.5/5	4.5/5	Feb 2013	599	ebay.com
14.		Sony A68	3/5	..	..	..	4/5	4/5	Nov 2015	699	ebay.com
15.		Sony A77	5/5	91/100	..	81/100	..	5/5	Aug 2011	1,399	ebay.com
16.		Sony A6500	5/5	+ +	3.5/5	85/100	4.5/5	4.5/5	Oct 2016	1,399	ebay.com
17.		Sony A6600	4/5	+	4/5	83/100	4.5/5	4/5	Aug 2019	1,399	amazon.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

Care should be taken when interpreting the review scores above, though. The ratings were established in reference to similarly priced cameras that were available in the market at the time of the review. 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. 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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