Canon T3i vs Sony A9
The Canon EOS Rebel T3i (called Canon 600D in some regions) and the Sony Alpha A9 are two digital cameras that were announced, respectively, in February 2011 and April 2017. The T3i is a DSLR, while the A9 is a mirrorless interchangeable lens camera. The cameras are based on an APS-C (T3i) and a full frame (A9) sensor. The Canon has a resolution of 17.9 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.
Going beyond this snapshot of core features and characteristics, what are the differences between the Canon EOS Rebel T3i and the Sony Alpha A9? 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 Canon T3i and the Sony A9. 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 measures are rounded to the nearest millimeter.
If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Sony A9 is notably smaller (8 percent) than the Canon T3i. However, the A9 is markedly heavier (18 percent) than the T3i. It is noteworthy in this context that the A9 is splash and dust-proof, while the T3i 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 Canon EF Lens Catalog (T3i) and the Sony FE Lens Catalog (A9). Mirrorless cameras, such as the A9, 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 T3i gets 440 shots out of its LP-E8 battery, while the A9 can take 650 images on a single charge of its NP-FZ100 power pack. The power pack in the A9 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. 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.||Canon T3i||133 mm||100 mm||80 mm||570 g||440||n||Feb 2011||599|
|2.||Sony A9||127 mm||96 mm||63 mm||673 g||650||Y||Apr 2017||4,499|
|3.||Canon SL2||122 mm||93 mm||70 mm||453 g||650||n||Jun 2017||549|
|4.||Canon T6s||132 mm||101 mm||78 mm||565 g||440||n||Feb 2015||649|
|5.||Canon T5||130 mm||100 mm||78 mm||480 g||500||n||Feb 2014||449|
|6.||Canon SL1||117 mm||91 mm||69 mm||407 g||380||n||Mar 2013||549|
|7.||Canon T5i||133 mm||100 mm||79 mm||580 g||440||n||Mar 2013||649|
|8.||Canon M||109 mm||66 mm||32 mm||298 g||230||n||Jul 2012||599|
|9.||Canon T4i||133 mm||100 mm||79 mm||575 g||440||n||Jun 2012||849|
|10.||Canon T3||130 mm||100 mm||78 mm||495 g||700||n||Feb 2011||449|
|11.||Canon T2i||129 mm||98 mm||62 mm||530 g||440||n||Feb 2010||699|
|12.||Canon T1i||129 mm||98 mm||62 mm||520 g||400||n||Mar 2009||799|
|13.||Sony A9 II||129 mm||96 mm||76 mm||678 g||690||Y||Oct 2019||4,499|
|14.||Sony A7 III||127 mm||96 mm||74 mm||650 g||610||Y||Feb 2018||1,999|
|15.||Sony A7R II||127 mm||96 mm||60 mm||625 g||290||Y||Jun 2015||3,199|
|16.||Sony A7S II||127 mm||96 mm||60 mm||627 g||370||Y||Sep 2015||2,999|
|17.||Sony A7 II||127 mm||96 mm||60 mm||599 g||350||Y||Nov 2014||1,999|
|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 T3i was launched at a markedly lower price (by 87 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. Then, after the new model is out, very good deals can frequently be found on the pre-owned market.
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 more expensive and lead to bigger and heavier cameras and lenses.
Of the two cameras under consideration, the Canon T3i features an APS-C sensor and the Sony A9 a full frame sensor. The sensor area in the A9 is 155 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.6 and 1.0. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.
With 24MP, the A9 offers a higher resolution than the T3i (17.9MP), but the A9 nevertheless has larger individual pixels (pixel pitch of 5.94μm versus 4.31μm for the T3i) due to its larger sensor. Moreover, the A9 is a much more recent model (by 6 years and 2 months) than the T3i, and its sensor will have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixel-units.
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 Canon T3i are 25.9 x 17.3 inches or 65.8 x 43.9 cm for good quality, 20.7 x 13.8 inches or 52.7 x 35.1 cm for very good quality, and 17.3 x 11.5 inches or 43.9 x 29.3 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 Canon EOS Rebel T3i has a native sensitivity range from ISO 100 to ISO 6400, which can be extended to ISO 100-12800. The corresponding ISO settings for the Sony Alpha A9 are ISO 100 to ISO 51200, with the possibility to increase the ISO range to 50-204800.
For many cameras, data on sensor performance has been reported by DXO Mark. 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"). Of the two cameras under consideration, the A9 offers substantially better image quality than the T3i (overall score 27 points higher). The advantage is based on 2.8 bits higher color depth, 1.8 EV in additional dynamic range, and 2.1 stops in additional low light sensitivity. The adjacent table reports on the physical sensor characteristics and the outcomes of the DXO sensor quality tests for a sample of comparator-cameras.
| DXO |
|2.||Sony A9||Full Frame||24.0||6000||4000||4K/30p||24.9||13.3||3517||92|
|13.||Sony A9 II||Full Frame||24.0||6000||4000||4K/30p||25.0||14.0||3434||93|
|14.||Sony A7 III||Full Frame||24.0||6000||4000||4K/30p||25.0||14.7||3730||96|
|15.||Sony A7R II||Full Frame||42.2||7952||5304||4K/30p||26.0||13.9||3434||98|
|16.||Sony A7S II||Full Frame||12.0||4240||2832||4K/30p||23.6||13.3||2993||85|
|17.||Sony A7 II||Full Frame||24.0||6000||4000||1080/60p||24.9||13.6||2449||90|
Many modern cameras cannot only take still pictures, but also record videos. Both cameras under consideration are equipped with sensors that have a sufficiently high read-out speed for moving images, but the A9 provides a better video resolution than the T3i. It can shoot movie footage at 4K/30p, while the Canon is limited to 1080/30p.
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), while the T3i 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 A9 offers a wider field of view (100%) than the one in the T3i (95%), so that a larger proportion of the captured image is visible in the finder. In addition, the viewfinder of the A9 has a higher magnification (0.78x vs 0.53x), so that the size of the image transmitted appears closer to the size seen with the naked human eye. The following table reports on some other key feature differences and similarities of the Canon T3i, the Sony A9, and comparable cameras.
|13.||Sony A9 II||3686||n||3.0||1440||tilting||Y||1/8000s||10.0||n||Y|
|14.||Sony A7 III||2359||n||3.0||922||tilting||Y||1/8000s||10.0||n||Y|
|15.||Sony A7R II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y|
|16.||Sony A7S II||2400||n||3.0||1229||tilting||n||1/8000s||5.0||n||Y|
|17.||Sony A7 II||2400||n||3.0||1230||tilting||n||1/8000s||5.0||n||Y|
One difference between the cameras concerns the presence of an on-board flash. The T3i has one, while the A9 does not. While the built-in flash of the T3i is not very powerful, it can at times be useful as a fill-in light.The T3i 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 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 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 T3i writes its imaging data to SDXC cards, while the A9 uses SDXC or Memory Stick PRO Duo cards. The A9 features dual card slots, which can be very useful in case a memory card fails. In contrast, the T3i only has one slot. The A9 supports UHS-II cards on its first slot and UHS-I on its second one, while the T3i 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 Canon EOS Rebel T3i and Sony Alpha A9 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|13.||Sony A9 II||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|14.||Sony A7 III||Y||stereo||mono||Y||Y||micro||3.1||Y||Y||Y|
|15.||Sony A7R II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|16.||Sony A7S II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
|17.||Sony A7 II||Y||stereo||mono||Y||Y||micro||2.0||Y||Y||-|
It is notable that the A9 offers wifi support, which can be a very convenient means to transfer image data to an off-camera location. In contrast, the T3i does not provide wifi capability.
Studio photographers will appreciate that the Sony A9 (unlike the T3i) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
Both the T3i and the A9 have been discontinued, but can regularly be found used on eBay. The T3i was replaced by the Canon T4i, while the A9 was followed 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 Canon and Sony websites.
So how do things add up? Which of the two cameras – the Canon T3i or the Sony A9 – has the upper hand? Is one clearly better than the other? A synthesis of the relative strong points of each of the models is listed below.
Reasons to prefer the Canon EOS Rebel T3i:
- Brighter framing: Features an optical viewfinder for clear, lag-free composition.
- More flexible LCD: Has a swivel 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.
- Less heavy: Is lighter (by 103g or 15 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 (87 percent cheaper at launch).
- More heavily discounted: Has been available for much longer (launched in February 2011).
Arguments in favor of the Sony Alpha A9:
- More detail: Has more megapixels (24 vs 17.9MP), which boosts linear resolution by 16%.
- Better image quality: Scores substantially higher (27 points) in the DXO overall evaluation.
- Richer colors: Generates noticeably more natural colors (2.8 bits more color depth).
- More dynamic range: Captures a broader range of light and dark details (1.8 EV of extra DR).
- Better low-light sensitivity: Can shoot in dim conditions (2.1 stops ISO advantage).
- Better video: Provides higher definition movie capture (4K/30p vs 1080/30p).
- Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
- 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 (0.78x vs 0.53x).
- More detailed LCD: Has a higher resolution rear screen (1440k vs 1040k dots).
- Fewer buttons to press: Has a touchscreen to facilitate handling and shooting adjustments.
- Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
- Faster burst: Shoots at higher frequency (20 vs 3.7 flaps/sec) to capture the decisive moment.
- Less disturbing: Has an electronic shutter option for completely silent shooting.
- Longer lasting: Gets more shots (650 versus 440) out of a single battery charge.
- Easier travel charging: Can be conveniently charged via its USB port.
- 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.
- 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.
- 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 Ultra High Speed (UHS-II and UHS-I) SDXC cards.
- More modern: Reflects 6 years and 2 months of technical progress since the T3i launch.
If the number of relative strengths (bullet points above) is taken as a guide, the A9 is the clear winner of the contest (28 : 7 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 Canon T3i and the Sony A9 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 incomplete and does no justice, for example, to the way the T3i or the A9 perform in practice. 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 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], 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.||Canon T3i||3/5||o||77/100||4.5/5||4.5/5||Feb 2011||599|
|2.||Sony A9||5/5||+ +||89/100||5/5||5/5||Apr 2017||4,499|
|3.||Canon SL2||4/5||+ +||78/100||4.5/5||4.5/5||Jun 2017||549|
|4.||Canon T6s||5/5||+||77/100||4.5/5||4.5/5||Feb 2015||649|
|5.||Canon T5||3/5||+||..||4/5||4.5/5||Feb 2014||449|
|6.||Canon SL1||4/5||+||78/100||4/5||4/5||Mar 2013||549|
|7.||Canon T5i||..||..||76/100||4.5/5||4.5/5||Mar 2013||649|
|8.||Canon M||3/5||+||..||4/5||4/5||Jul 2012||599|
|9.||Canon T4i||4/5||+ +||77/100||4.5/5||4.5/5||Jun 2012||849|
|10.||Canon T3||..||80/100||69/100||4/5||4.5/5||Feb 2011||449|
|11.||Canon T2i||..||+ +||77/100||4/5||4.5/5||Feb 2010||699|
|12.||Canon T1i||..||+ +||74/100||4.5/5||4.5/5||Mar 2009||799|
|13.||Sony A9 II||..||..||90/100||5/5||5/5||Oct 2019||4,499|
|14.||Sony A7 III||..||+ +||89/100||5/5||5/5||Feb 2018||1,999|
|15.||Sony A7R II||5/5||+ +||90/100||5/5||5/5||Jun 2015||3,199|
|16.||Sony A7S II||5/5||+||..||4.5/5||5/5||Sep 2015||2,999|
|17.||Sony A7 II||5/5||+||82/100||4.5/5||5/5||Nov 2014||1,999|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
The above review scores should be interpreted with care, though. The ratings were established in reference to similarly priced cameras that were available in the market at the time of the review. Hence, a score should always be seen in the context of the camera's market launch date and its price, and comparisons of ratings among very different cameras or across long time periods 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 are interested in seeing how other cameras pair up, just make a corresponding selection in the search boxes below. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.
Specifications: Canon T3i vs Sony A9
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||Canon T3i||Sony A9|
|Camera Type||Digital single lens reflex||Mirrorless system camera|
|Camera Lens||Canon EF mount lenses||Sony E mount lenses|
|Launch Date||February 2011||April 2017|
|Launch Price||USD 599||USD 4,499|
|Sensor Specs||Canon T3i||Sony A9|
|Sensor Format||APS-C Sensor||Full Frame Sensor|
|Sensor Size||22.3 x 14.9 mm||35.6 x 23.8 mm|
|Sensor Area||332.27 mm2||847.28 mm2|
|Sensor Diagonal||26.8 mm||42.8 mm|
|Sensor Resolution||17.9 Megapixels||24 Megapixels|
|Image Resolution||5184 x 3456 pixels||6000 x 4000 pixels|
|Pixel Pitch||4.31 μm||5.94 μm|
|Pixel Density||5.39 MP/cm2||2.83 MP/cm2|
|Moiré control||Anti-Alias filter||Anti-Alias filter|
|Movie Capability||1080/30p Video||4K/30p Video|
|ISO Setting||100 - 6,400 ISO||100 - 51,200 ISO|
|ISO Boost||100 - 12,800 ISO||50 - 204,800 ISO|
|Image Processor||DIGIC 4||BIONZ X|
|DXO Sensor Quality (score)||65||92|
|DXO Color Depth (bits)||22.1||24.9|
|DXO Dynamic Range (EV)||11.5||13.3|
|DXO Low Light (ISO)||793||3517|
|Screen Specs||Canon T3i||Sony A9|
|Viewfinder Type||Optical viewfinder||Electronic viewfinder|
|Viewfinder Field of View||95%||100%|
|Viewfinder Resolution||3686k dots|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.0inch|
|LCD Resolution||1040k dots||1440k dots|
|LCD Attachment||Swivel screen||Tilting screen|
|Touch Input||no Touchscreen||Touchscreen|
|Shooting Specs||Canon T3i||Sony A9|
|Focus System||Phase-detect AF||On-Sensor Phase-detect|
|Manual Focusing Aid||no Peaking Feature||Focus Peaking|
|Max Shutter Speed (mechanical)||1/4000s||1/8000s|
|Continuous Shooting||3.7 shutter flaps/s||20 shutter flaps/s|
|Shutter Life Expectancy||100 000 actuations||500 000 actuations|
|Electronic Shutter||no E-Shutter||up to 1/32000s|
|Image Stabilization||Lens stabilization only||In-body stabilization|
|Fill Flash||Build-in Flash||no On-Board Flash|
|Storage Medium||SDXC cards||MS or SDXC cards|
|Second Storage Option||Single card slot||Dual card slots|
|UHS card support||no||Single UHS-II|
|Connectivity Specs||Canon T3i||Sony A9|
|Studio Flash||no PC Sync||PC Sync socket|
|USB Connector||USB 2.0||USB 2.0|
|HDMI Port||mini HDMI||micro HDMI|
|Microphone Port||External MIC port||External MIC port|
|Headphone Socket||no Headphone port||Headphone port|
|Wifi Support||no Wifi||Wifi built-in|
|Near-Field Communication||no NFC||NFC built-in|
|Bluetooth Support||no Bluetooth||Bluetooth built-in|
|Body Specs||Canon T3i||Sony A9|
|Environmental Sealing||not weather sealed||Weathersealed body|
|Battery Life (CIPA)||440 shots per charge||650 shots per charge|
|In-Camera Charging||no USB charging||USB charging|
133 x 100 x 80 mm
(5.2 x 3.9 x 3.1 in)
127 x 96 x 63 mm
(5.0 x 3.8 x 2.5 in)
|Camera Weight||570 g (20.1 oz)||673 g (23.7 oz)|
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