Sony A5100 vs A9 II
The Sony Alpha A5100 and the Sony Alpha A9 II are two digital cameras that were revealed to the public, respectively, in August 2014 and October 2019. Both the A5100 and the A9 II are mirrorless interchangeable lens cameras that are based on an APS-C (A5100) and a full frame (A9 II) 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.
Going beyond this snapshot of core features and characteristics, what are the differences between the Sony Alpha A5100 and the Sony Alpha A9 II? 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 physical size and weight of the Sony A5100 and the Sony A9 II are illustrated 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 size dimensions are rounded to the nearest millimeter.
The A5100 can be obtained in two different colors (black, white), while the A9 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 Sony A9 II is considerably larger (79 percent) than the Sony A5100. Moreover, the A9 II is substantially heavier (140 percent) than the A5100. It is noteworthy in this context that the A9 II is splash and dust-proof, while the A5100 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 E-Mount Lens Catalog (A5100) and the Sony FE Lens Catalog (A9 II). 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 A5100 gets 400 shots out of its NP-FW50 battery, while the A9 II can take 690 images on a single charge of its NP-FZ100 power pack. The battery packs of both cameras can be charged via USB, 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. 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 A5100||110 mm||63 mm||36 mm||283 g||400||n||Aug 2014||549|
|2.||Sony A9 II||129 mm||96 mm||76 mm||678 g||690||Y||Oct 2019||4,499|
|3.||Sony A7S III||127 mm||97 mm||81 mm||699 g||600||Y||Jul 2020||3,499|
|4.||Sony A7C||124 mm||71 mm||60 mm||509 g||740||Y||Sep 2020||1,799|
|5.||Sony A7R IV||129 mm||96 mm||78 mm||665 g||670||Y||Jul 2019||3,499|
|6.||Sony A7 III||127 mm||96 mm||74 mm||650 g||610||Y||Feb 2018||1,999|
|7.||Sony A9||127 mm||96 mm||63 mm||673 g||650||Y||Apr 2017||4,499|
|8.||Sony RX100 IV||102 mm||58 mm||41 mm||298 g||280||n||Jun 2015||999|
|9.||Sony A5000||110 mm||63 mm||36 mm||269 g||420||n||Jan 2014||449|
|10.||Sony A6000||120 mm||67 mm||45 mm||344 g||360||n||Feb 2014||599|
|11.||Sony RX100 III||102 mm||58 mm||41 mm||290 g||320||n||May 2014||799|
|12.||Sony A3000||128 mm||91 mm||85 mm||411 g||470||n||Aug 2013||329|
|13.||Sony NEX-3N||110 mm||62 mm||35 mm||269 g||480||n||Feb 2013||499|
|14.||Sony RX100 II||102 mm||58 mm||38 mm||281 g||350||n||Jun 2013||749|
|15.||Sony NEX-F3||117 mm||67 mm||42 mm||314 g||470||n||May 2012||599|
|16.||Sony RX100||102 mm||58 mm||36 mm||240 g||330||n||Jun 2012||649|
|17.||Sony NEX-3||117 mm||62 mm||33 mm||297 g||330||n||May 2010||599|
|Notes: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.|
The price is, of course, an important factor in any camera decision. The listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The A5100 was launched at a markedly lower price (by 88 percent) than the A9 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.
The size of the imaging sensor is a crucial determinant 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. 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 associated with larger, more expensive camera bodies and lenses.
Of the two cameras under consideration, the Sony A5100 features an APS-C sensor and the Sony A9 II a full frame sensor. The sensor area in the A9 II is 131 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 A9 II has a larger sensor, both cameras offer the same resolution of 24 megapixels. This implies that the A9 II has a lower pixel density and larger individual pixels (with a pixel pitch of 5.94μm versus 3.91μm for the A5100), which gives it a potential advantage in terms of light gathering capacity. In addition, the A9 II is much more recent (by 5 years and 1 month) than the A5100, and its sensor will have benefitted from technological advances during this time.
The Sony Alpha A5100 has a native sensitivity range from ISO 100 to ISO 25600. The corresponding ISO settings for the Sony Alpha A9 II are ISO 100 to ISO 51200, with the possibility to increase the ISO range to 50-204800.
Since 2007, DXO Mark has published sensor performance measurements that have been derived using a consistent methodology. 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 A9 II offers substantially better image quality than the A5100 (overall score 13 points higher). The advantage is based on 1.2 bits higher color depth, 1.3 EV in additional dynamic range, and 1.4 stops in additional low light sensitivity. The following table provides an overview of the physical sensor characteristics, as well as the sensor quality measurements for a selection of comparators.
| DXO |
|2.||Sony A9 II||Full Frame||24.0||6000||4000||4K/30p||25.0||14.0||3434||93|
|3.||Sony A7S III||Full Frame||12.0||4240||2832||4K/120p||23.7||13.9||2520||86|
|4.||Sony A7C||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3407||95|
|5.||Sony A7R IV||Full Frame||60.2||9504||6336||4K/30p||26.0||14.8||3344||99|
|6.||Sony A7 III||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3730||96|
|7.||Sony A9||Full Frame||24.0||6000||4000||4K/30p||24.9||13.3||3517||92|
|8.||Sony RX100 IV||1-inch||20.0||5472||3648||4K/30p||22.8||12.6||591||70|
|11.||Sony RX100 III||1-inch||20.0||5472||3648||1080/60p||22.4||12.3||495||67|
|14.||Sony RX100 II||1-inch||20.0||5472||3648||1080/60p||22.5||12.4||483||67|
Many modern cameras are not only capable of taking still images, but also of capturing video footage. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, but the A9 II provides a better video resolution than the A5100. It can shoot movie footage at 4K/30p, while the A5100 is limited to 1080/60p.
Beyond body and sensor, cameras can and do differ across a range of features. For example, the A9 II has an electronic viewfinder (3686k dots), which can be very helpful when shooting in bright sunlight. In contrast, the A5100 relies on live view and the rear LCD for framing. The adjacent table lists some of the other core features of the Sony A5100 and Sony A9 II along with similar information for a selection of comparators.
|2.||Sony A9 II||3686||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|3.||Sony A7S III||9440||n||3.0||1440||swivel||Y||1/8000s||10.0||n||Y|
|5.||Sony A7R IV||5760||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|6.||Sony A7 III||2359||n||3.0||922||tilting||Y||1/8000s||10.0||n||Y|
|8.||Sony RX100 IV||2359||n||3.0||1228||tilting||n||1/2000s||16.0||Y||Y|
|11.||Sony RX100 III||1440||n||3.0||1229||tilting||n||1/2000s||10.0||Y||Y|
|14.||Sony RX100 II||optional||n||3.0||1229||tilting||n||1/2000s||10.0||Y||Y|
One difference between the cameras concerns the presence of an on-board flash. The A5100 has one, while the A9 II 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.The A5100 has an articulated LCD that can be turned to be front-facing. This characteristic will be appreciated by vloggers and photographers who are interested in snapping selfies. In contrast, the A9 II does not have a selfie-screen.
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 II 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 Sony A9 II 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 A5100 writes its imaging data to SDXC or Memory Stick PRO Duo cards, while the A9 II uses SDXC cards. The A9 II features dual card slots, which can be very useful in case a memory card fails. In contrast, the A5100 only has one slot. The A9 II supports UHS-II cards (on both slots), while the A5100 can use UHS-I 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 A5100 and Sony Alpha A9 II and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|2.||Sony A9 II||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|3.||Sony A7S III||Y||stereo||mono||Y||Y||full||3.2||Y||-||Y|
|5.||Sony A7R IV||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|6.||Sony A7 III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|8.||Sony RX100 IV||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
|11.||Sony RX100 III||-||stereo||mono||-||-||micro||2.0||Y||Y||-|
|14.||Sony RX100 II||Y||stereo||mono||-||-||micro||2.0||Y||Y||-|
It is notable that the A9 II has a headphone jack, which makes it possible to attach external headphones and monitor the quality of sound during the recording process. The A5100 lacks such a headphone port.
Studio photographers will appreciate that the Sony A9 II (unlike the A5100) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
Both the A5100 and the A9 II are recent models that are part of the current product line-up. The A5100 replaced the earlier Sony A5000, while the A9 II followed on from the Sony A9. Further information on the two cameras (e.g. user guides, manuals), as well as related accessories, can be found on the official Sony website.
So what conclusions can be drawn? Is there a clear favorite between the Sony A5100 and the Sony A9 II? Which camera is better? The listing below highlights the relative strengths of the two models.
Arguments in favor of the Sony Alpha A5100:
- More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
- More compact: Is smaller (110x63mm vs 129x96mm) and thus needs less room in the bag.
- Less heavy: Is lighter (by 395g or 58 percent) and hence easier to carry around.
- Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
- More affordable: Was introduced into a lower priced category (88 percent cheaper at launch).
- More heavily discounted: Has been available for much longer (launched in August 2014).
Advantages of the Sony Alpha A9 II:
- Better image quality: Scores substantially higher (13 points) in the DXO overall evaluation.
- Richer colors: Generates noticeably more natural colors (1.2 bits more color depth).
- More dynamic range: Captures a broader range of light and dark details (1.3 EV of extra DR).
- Better low-light sensitivity: Can shoot in dim conditions (1.4 stops ISO advantage).
- Better video: Provides higher definition movie capture (4K/30p vs 1080/60p).
- 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 922k dots).
- Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
- Faster burst: Shoots at higher frequency (10 vs 6 flaps/sec) to capture the decisive moment.
- Less disturbing: Has an electronic shutter option for completely silent shooting.
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- Longer lasting: Gets more shots (690 versus 400) out of a single battery charge.
- Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
- Sharper images: Has stabilization technology built-in to reduce the impact of hand-shake.
- Better lighting: Features a hotshoe and can thus hold and trigger an external flash gun.
- Faster data transfer: Supports a more advanced USB protocol (3.1 vs 2.0).
- Easier wireless transfer: Supports Bluetooth for image sharing without cables.
- 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 a more advanced SD data transfer standard (UHS-II vs UHS-I).
- More modern: Reflects 5 years and 1 month of technical progress since the A5100 launch.
If the count of relative strengths (bullet points above) is taken as a measure, the A9 II is the clear winner of the contest (23 : 6 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 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 A9 II 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 specs-based evaluation of cameras can be instructive in revealing their potential as photographic tools, it says little about, for example, the shooting experience and imaging performance of the A5100 and the A9 II in practical situations. User reviews, such as those found at amazon, can sometimes inform about these issues, but such feedback is often incomplete, inconsistent, and biased.
This is where reviews by experts come in. The table below provides a synthesis of the camera assessments of some of the best known photo-gear 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 A5100||4.5/5||+||..||4.5/5||5/5||Aug 2014||549|
|2.||Sony A9 II||..||..||90/100||5/5||5/5||Oct 2019||4,499|
|3.||Sony A7S III||..||+ +||91/100||4.5/5||5/5||Jul 2020||3,499|
|4.||Sony A7C||3.5/5||..||86/100||4/5||4/5||Sep 2020||1,799|
|5.||Sony A7R IV||5/5||+||91/100||4.5/5||5/5||Jul 2019||3,499|
|6.||Sony A7 III||..||+ +||89/100||5/5||5/5||Feb 2018||1,999|
|7.||Sony A9||5/5||+ +||89/100||5/5||5/5||Apr 2017||4,499|
|8.||Sony RX100 IV||4.5/5||+ +||85/100||4/5||4.5/5||Jun 2015||999|
|9.||Sony A5000||3/5||+||..||4.5/5||4.5/5||Jan 2014||449|
|10.||Sony A6000||5/5||+||80/100||4.5/5||5/5||Feb 2014||599|
|11.||Sony RX100 III||5/5||+ +||82/100||4.5/5||5/5||May 2014||799|
|12.||Sony A3000||3/5||+||..||4/5||4/5||Aug 2013||329|
|13.||Sony NEX-3N||3/5||..||..||4.5/5||4.5/5||Feb 2013||499|
|14.||Sony RX100 II||5/5||+ +||79/100||4.5/5||4.5/5||Jun 2013||749|
|15.||Sony NEX-F3||4/5||..||74/100||4.5/5||4.5/5||May 2012||599|
|16.||Sony RX100||5/5||+ +||78/100||4/5||5/5||Jun 2012||649|
|17.||Sony NEX-3||..||..||70/100||4.5/5||4/5||May 2010||599|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
The review scores listed above should be treated with care, though. The ratings are only valid when referring to cameras in the same category and of the same age. Thus, a score needs to be put into the context of the launch date and the launch price of the camera, and comparing ratings of very distinct cameras or ones that are far apart in terms of their release date have little meaning. Also, please note that some of the review sites have changed their methodology and reporting over time.
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 use the search menu below. As an alternative, you can also directly jump to any one of the listed comparisons that were previously generated by the CAM-parator tool.
Specifications: Sony A5100 vs Sony A9 II
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 A5100||Sony A9 II|
|Camera Type||Mirrorless system camera||Mirrorless system camera|
|Camera Lens||Sony E mount lenses||Sony E mount lenses|
|Launch Date||August 2014||October 2019|
|Launch Price||USD 549||USD 4,499|
|Sensor Specs||Sony A5100||Sony A9 II|
|Sensor Format||APS-C Sensor||Full Frame Sensor|
|Sensor Size||23.5 x 15.6 mm||35.6 x 23.8 mm|
|Sensor Area||366.6 mm2||847.28 mm2|
|Sensor Diagonal||28.2 mm||42.8 mm|
|Sensor Resolution||24 Megapixels||24 Megapixels|
|Image Resolution||6000 x 4000 pixels||6000 x 4000 pixels|
|Pixel Pitch||3.91 μm||5.94 μm|
|Pixel Density||6.55 MP/cm2||2.83 MP/cm2|
|Moiré control||Anti-Alias filter||Anti-Alias filter|
|Movie Capability||1080/60p Video||4K/30p Video|
|ISO Setting||100 - 25,600 ISO||100 - 51,200 ISO|
|ISO Boost||no Enhancement||50 - 204,800 ISO|
|Image Processor||BIONZ X||BIONZ X|
|DXO Sensor Quality (score)||80||93|
|DXO Color Depth (bits)||23.8||25.0|
|DXO Dynamic Range (EV)||12.7||14.0|
|DXO Low Light (ISO)||1347||3434|
|Screen Specs||Sony A5100||Sony A9 II|
|Viewfinder Type||no viewfinder||Electronic 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||922k dots||1440k dots|
|LCD Attachment||Tilting screen||Tilting screen|
|Shooting Specs||Sony A5100||Sony A9 II|
|Focus System||On-Sensor Phase-detect||On-Sensor Phase-detect|
|Manual Focusing Aid||Focus Peaking||Focus Peaking|
|Max Shutter Speed (mechanical)||1/4000s||1/8000s|
|Continuous Shooting||6 shutter flaps/s||10 shutter flaps/s|
|Electronic Shutter||no E-Shutter||up to 1/32000s|
|Time-Lapse Photography||no Intervalometer||Intervalometer built-in|
|Image Stabilization||Lens stabilization only||In-body stabilization|
|Fill Flash||Build-in Flash||no On-Board Flash|
|Storage Medium||MS or SDXC cards||SDXC cards|
|Second Storage Option||Single card slot||Dual card slots|
|UHS card support||UHS-I||Dual UHS-II|
|Connectivity Specs||Sony A5100||Sony A9 II|
|External Flash||no Hotshoe||Hotshoe|
|Studio Flash||no PC Sync||PC Sync socket|
|USB Connector||USB 2.0||USB 3.1|
|HDMI Port||micro HDMI||micro HDMI|
|Microphone Port||no MIC socket||External MIC port|
|Headphone Socket||no Headphone port||Headphone port|
|Wifi Support||Wifi built-in||Wifi built-in|
|Near-Field Communication||NFC built-in||NFC built-in|
|Bluetooth Support||no Bluetooth||Bluetooth built-in|
|Body Specs||Sony A5100||Sony A9 II|
|Environmental Sealing||not weather sealed||Weathersealed body|
|Battery Life (CIPA)||400 shots per charge||690 shots per charge|
|In-Camera Charging||USB charging||USB charging|
110 x 63 x 36 mm
(4.3 x 2.5 x 1.4 in)
129 x 96 x 76 mm
(5.1 x 3.8 x 3.0 in)
|Camera Weight||283 g (10.0 oz)||678 g (23.9 oz)|
Did you notice an error on this page? If so, please get in touch, so that we can correct the information.