Sony A9 vs YI M1
The Sony Alpha A9 and the YI M1 are two digital cameras that were officially introduced, respectively, in April 2017 and September 2016. Both the A9 and the M1 are mirrorless interchangeable lens cameras that are based on a full frame (A9) 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.
Going beyond this snapshot of core features and characteristics, what are the differences between the Sony Alpha A9 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.
The side-by-side display below illustrates the physical size and weight of the Sony A9 and the YI M1. 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 M1 can be obtained in two different colors (black, silver), while the A9 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 (40 percent) than the Sony A9. Moreover, the M1 is substantially lighter (58 percent) than the A9. It is worth mentioning in this context that the A9 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. 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 Sony FE Lens Catalog (A9) and the Micro Four Thirds Lens Catalog (M1). 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 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.
|1.||Sony A9||127 mm||96 mm||63 mm||673 g||650||Y||Apr 2017||4,499|
|2.||YI M1||114 mm||64 mm||34 mm||281 g||450||n||Sep 2016||349|
|3.||Canon SX730||110 mm||64 mm||40 mm||300 g||250||n||Apr 2017||399|
|4.||Fujifilm X-A3||117 mm||67 mm||40 mm||339 g||410||n||Aug 2016||399|
|5.||Nikon Z6||134 mm||101 mm||67 mm||675 g||310||Y||Aug 2018||1,999|
|6.||Nikon 1 J5||98 mm||60 mm||32 mm||231 g||250||n||Apr 2015||399|
|7.||Panasonic GX850||107 mm||65 mm||33 mm||269 g||210||n||Jan 2017||549|
|8.||Panasonic GF7||107 mm||65 mm||33 mm||266 g||230||n||Jan 2015||499|
|9.||Sony A7C||124 mm||71 mm||60 mm||509 g||740||Y||Sep 2020||1,799|
|10.||Sony A9 II||129 mm||96 mm||76 mm||678 g||690||Y||Oct 2019||4,499|
|11.||Sony A7R IV||129 mm||96 mm||78 mm||665 g||670||Y||Jul 2019||3,499|
|12.||Sony A7 III||127 mm||96 mm||74 mm||650 g||610||Y||Feb 2018||1,999|
|13.||Sony A7R III||127 mm||96 mm||74 mm||650 g||650||Y||Oct 2017||3,199|
|14.||Sony A7R II||127 mm||96 mm||60 mm||625 g||290||Y||Jun 2015||3,199|
|15.||Sony A7S II||127 mm||96 mm||60 mm||627 g||370||Y||Sep 2015||2,999|
|16.||Sony A7 II||127 mm||96 mm||60 mm||599 g||350||Y||Nov 2014||1,999|
|17.||Sony A99||147 mm||111 mm||78 mm||812 g||500||Y||Sep 2012||2,799|
|Notes: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.|
Any camera decision will naturally be influenced heavily by the price. The listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The M1 was launched at a markedly lower price (by 92 percent) than the A9, 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.
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. Further, a large sensor camera will give the photographer additional creative options when using shallow depth-of-field to isolate a subject from its 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 A9 features a full frame sensor and the YI M1 a Four Thirds sensor. The sensor area in the M1 is 73 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.0 and 2.0. The sensor in the A9 has a native 3:2 aspect ratio, while the one in the M1 offers a 4:3 aspect.
With 24MP, the A9 offers a higher resolution than the M1 (20.2MP), but the A9 nevertheless has larger individual pixels (pixel pitch of 5.94μm versus 3.34μm for the M1) due to its larger sensor. Moreover, the A9 is a somewhat more recent model (by 6 months) than the M1, and its sensor might have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixels.
The resolution advantage of the Sony A9 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A9 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 A9 has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.
The Sony Alpha A9 has a native sensitivity range from ISO 100 to ISO 51200, which can be extended to ISO 50-204800. The corresponding ISO settings for the YI M1 are ISO 100 to ISO 25600 (no boost).
Consistent information on actual sensor performance is available from DXO Mark for many cameras. 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 following table provides an overview of the physical sensor characteristics, as well as the sensor quality measurements for a selection of comparators.
| DXO |
|1.||Sony A9||Full Frame||24.0||6000||4000||4K/30p||24.9||13.3||3517||92|
|2.||YI M1||Four Thirds||20.2||5184||3888||4K/30p||..||..||..||..|
|5.||Nikon Z6||Full Frame||24.3||6048||4024||4K/30p||25.3||14.3||3299||95|
|6.||Nikon 1 J5||1-inch||20.7||5568||3712||4K/15p||21.1||12.0||479||65|
|7.||Panasonic GX850||Four Thirds||15.8||4592||3448||4K/30p||23.2||13.3||586||73|
|8.||Panasonic GF7||Four Thirds||15.8||4592||3448||1080/60p||..||..||..||..|
|9.||Sony A7C||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3407||95|
|10.||Sony A9 II||Full Frame||24.0||6000||4000||4K/30p||25.0||14.0||3434||93|
|11.||Sony A7R IV||Full Frame||60.2||9504||6336||4K/30p||26.0||14.8||3344||99|
|12.||Sony A7 III||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3730||96|
|13.||Sony A7R III||Full Frame||42.2||7952||5304||4K/30p||26.0||14.7||3523||100|
|14.||Sony A7R II||Full Frame||42.2||7952||5304||4K/30p||26.0||13.9||3434||98|
|15.||Sony A7S II||Full Frame||12.0||4240||2832||4K/30p||23.6||13.3||2993||85|
|16.||Sony A7 II||Full Frame||24.0||6000||4000||1080/60p||24.9||13.6||2449||90|
|17.||Sony A99||Full Frame||24.0||6000||4000||1080/60p||25.0||14.0||1555||89|
Many modern cameras are not only capable of taking still images, but can also record movies. Both cameras under consideration are equipped with sensors that have a sufficiently high read-out speed for moving images, and both provide the same movie specifications (4K/30p).
Apart from body and sensor, cameras can and do differ across a range of features. For example, the A9 has an electronic viewfinder (3686k 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 table below summarizes some of the other core capabilities of the Sony A9 and YI M1 in connection with corresponding information for a sample of similar cameras.
|6.||Nikon 1 J5||none||n||3.0||1037||tilting||Y||1/4000s||60.0||Y||n|
|10.||Sony A9 II||3686||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|11.||Sony A7R IV||5760||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|12.||Sony A7 III||2359||n||3.0||922||tilting||Y||1/8000s||10.0||n||Y|
|13.||Sony A7R III||3686||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|14.||Sony A7R II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y|
|15.||Sony A7S II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y|
|16.||Sony A7 II||2400||n||3.0||1230||tilting||n||1/8000s||5.0||n||Y|
One feature that differentiates the A9 and the M1 is in-body image stabilization (IBIS). The A9 reduces the risk of handshake-induced blur with all attached lenses, while the M1 offers no blur reduction with lenses that themselves do not provide optical image stabilization.
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 A9 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 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 A9 writes its imaging data to SDXC or Memory Stick PRO Duo cards, while the M1 uses SDXC cards. The A9 features dual card slots, which can be very useful in case a memory card fails. In contrast, the M1 only has one slot. The A9 supports UHS-II cards on its first slot and UHS-I on its second one, while the M1 cannot take advantage of Ultra High Speed SD cards.
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 A9 and YI M1 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|6.||Nikon 1 J5||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
|10.||Sony A9 II||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|11.||Sony A7R IV||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|12.||Sony A7 III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|13.||Sony A7R III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|14.||Sony A7R II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|15.||Sony A7S II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|16.||Sony A7 II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
It is notable that the A9 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 A9 (unlike the M1) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
The M1 is a recent model that features in the current product line-up of YI. In contrast, the A9 has been discontinued (but can be found pre-owned on eBay). As a replacement in the same line of cameras, the A9 was succeeded by the Sony A9 II. Further information on the two cameras (e.g. user guides, manuals), as well as related accessories, can be found on the official Sony and YI websites.
So what conclusions can be drawn? Is the Sony A9 better than the YI M1 or vice versa? Below is a summary of the relative strengths of each of the two contestants.
Reasons to prefer the Sony Alpha A9:
- More detail: Offers more megapixels (24 vs 20.2MP) with a 11% higher linear resolution.
- Better image quality: Features a larger and more technologically advanced imaging 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 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 (1440k 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.
- Faster burst: Shoots at higher frequency (20 vs 5 flaps/sec) to capture the decisive moment.
- Less disturbing: Has an electronic shutter option for completely silent shooting.
- Longer lasting: Can take more shots (650 versus 450) on a single battery charge.
- Better sealing: Is weather sealed to enable shooting in dusty or wet environments.
- Sharper images: Has hand-shake reducing image stabilization built-in.
- 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.
- Greater peace of mind: Features a second card slot as a backup in case of memory card failure.
- Faster buffer clearing: Supports Ultra High Speed (UHS-II and UHS-I) SDXC cards.
- More modern: Is somewhat more recent (announced 6 months after the M1).
Advantages of the YI M1:
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- More compact: Is smaller (114x64mm vs 127x96mm) and will fit more readily into a bag.
- Less heavy: Has a lower weight (by 392g or 58 percent) and is thus easier to take along.
- More affordable: Was introduced into a lower priced category (92 percent cheaper at launch).
- More heavily discounted: Has been on the market for longer (launched in September 2016).
If the count of individual advantages (bullet points above) is taken as a guide, the A9 is the clear winner of the match-up (22 : 5 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 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 A9 and the YI M1 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 says little about, for example, the shooting experience and imaging performance of the A9 and the M1 in practical situations. 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.
This is why expert reviews are important. The adjacent summary-table relays the overall verdicts of several of the most popular camera review sites (amateurphotographer [AP], cameralabs [CL], 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.
|1.||Sony A9||5/5||+ +||89/100||5/5||5/5||Apr 2017||4,499|
|2.||YI M1||..||..||69/100||..||..||Sep 2016||349|
|3.||Canon SX730||..||+||..||4/5||4/5||Apr 2017||399|
|4.||Fujifilm X-A3||..||..||74/100||4.5/5||4/5||Aug 2016||399|
|5.||Nikon Z6||5/5||..||..||4.5/5||5/5||Aug 2018||1,999|
|6.||Nikon 1 J5||..||..||..||4.5/5||4.5/5||Apr 2015||399|
|7.||Panasonic GX850||..||+||76/100||4.5/5||4.5/5||Jan 2017||549|
|8.||Panasonic GF7||4/5||+||..||4.5/5||4.5/5||Jan 2015||499|
|9.||Sony A7C||3.5/5||..||86/100||4/5||4/5||Sep 2020||1,799|
|10.||Sony A9 II||..||..||90/100||5/5||5/5||Oct 2019||4,499|
|11.||Sony A7R IV||5/5||+||91/100||4.5/5||5/5||Jul 2019||3,499|
|12.||Sony A7 III||..||+ +||89/100||5/5||5/5||Feb 2018||1,999|
|13.||Sony A7R III||..||+ +||90/100||4.5/5||5/5||Oct 2017||3,199|
|14.||Sony A7R II||5/5||+ +||90/100||5/5||5/5||Jun 2015||3,199|
|15.||Sony A7S II||5/5||+||..||4.5/5||5/5||Sep 2015||2,999|
|16.||Sony A7 II||5/5||+||82/100||4.5/5||5/5||Nov 2014||1,999|
|17.||Sony A99||5/5||..||84/100||4.5/5||4.5/5||Sep 2012||2,799|
|Notes: (+ +) 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. 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. It should also be noted that some of the review sites have over time altered the way they render their verdicts.
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 make a corresponding selection in the search boxes below. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.
Specifications: Sony A9 vs YI M1
Below is a side-by-side comparison of the specs of the two cameras to facilitate a quick review of their differences and common features.
|Camera Model||Sony A9||YI M1|
|Camera Type||Mirrorless system camera||Mirrorless system camera|
|Camera Lens||Sony E mount lenses||Micro Four Thirds lenses|
|Launch Date||April 2017||September 2016|
|Launch Price||USD 4,499||USD 349|
|Sensor Specs||Sony A9||YI M1|
|Sensor Format||Full Frame Sensor||Four Thirds Sensor|
|Sensor Size||35.6 x 23.8 mm||17.3 x 13.0 mm|
|Sensor Area||847.28 mm2||224.9 mm2|
|Sensor Diagonal||42.8 mm||21.6 mm|
|Sensor Resolution||24 Megapixels||20.2 Megapixels|
|Image Resolution||6000 x 4000 pixels||5184 x 3888 pixels|
|Pixel Pitch||5.94 μm||3.34 μm|
|Pixel Density||2.83 MP/cm2||8.96 MP/cm2|
|Moiré control||Anti-Alias filter||Anti-Alias filter|
|Movie Capability||4K/30p Video||4K/30p Video|
|ISO Setting||100 - 51,200 ISO||100 - 25,600 ISO|
|ISO Boost||50 - 204,800 ISO||no Enhancement|
|DXO Sensor Quality (score)||92||..|
|DXO Color Depth (bits)||24.9||..|
|DXO Dynamic Range (EV)||13.3||..|
|DXO Low Light (ISO)||3517||..|
|Screen Specs||Sony A9||YI M1|
|Viewfinder Type||Electronic viewfinder||no viewfinder|
|Viewfinder Field of View||100%|
|Viewfinder Resolution||3686k dots|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||1440k dots||1040k dots|
|LCD Attachment||Tilting screen||Fixed screen|
|Shooting Specs||Sony A9||YI M1|
|Focus System||On-Sensor Phase-detect||Contrast-detect AF|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/8000s||1/4000s|
|Continuous Shooting||20 shutter flaps/s||5 shutter flaps/s|
|Electronic Shutter||up to 1/32000s||no E-Shutter|
|Time-Lapse Photography||no Intervalometer||Intervalometer built-in|
|Image Stabilization||In-body stabilization||Lens stabilization only|
|Fill Flash||no On-Board Flash||no On-Board Flash|
|Storage Medium||MS or SDXC cards||SDXC cards|
|Second Storage Option||Dual card slots||Single card slot|
|UHS card support||Single UHS-II||no|
|Connectivity Specs||Sony A9||YI M1|
|Studio Flash||PC Sync socket||no PC Sync|
|USB Connector||USB 2.0||USB 2.0|
|HDMI Port||micro HDMI||micro HDMI|
|Microphone Port||External MIC port||no MIC socket|
|Headphone Socket||Headphone port||no Headphone port|
|Wifi Support||Wifi built-in||Wifi built-in|
|Near-Field Communication||NFC built-in||no NFC|
|Bluetooth Support||Bluetooth built-in||Bluetooth built-in|
|Body Specs||Sony A9||YI M1|
|Environmental Sealing||Weathersealed body||not weather sealed|
|Battery Life (CIPA)||650 shots per charge||450 shots per charge|
|In-Camera Charging||USB charging||USB charging|
127 x 96 x 63 mm
(5.0 x 3.8 x 2.5 in)
114 x 64 x 34 mm
(4.5 x 2.5 x 1.3 in)
|Camera Weight||673 g (23.7 oz)||281 g (9.9 oz)|
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