Canon T3i vs Pentax K-3
The Canon EOS Rebel T3i (called Canon 600D in some regions) and the Pentax K-3 are two digital cameras that were announced, respectively, in February 2011 and October 2013. Both are DSLR (Digital Single Lens Reflex) cameras that are equipped with an APS-C sensor. The Canon has a resolution of 17.9 megapixels, whereas the Pentax provides 24.1 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 Pentax K-3? 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 Canon T3i and the Pentax K-3 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 K-3 can be obtained in two different colors (black, silver), while the T3i 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 Pentax K-3 is somewhat smaller (2 percent) than the Canon T3i. However, the K-3 is substantially heavier (40 percent) than the T3i. It is noteworthy in this context that the K-3 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. 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.
The following table provides a synthesis of the main physical specifications of the two cameras and other similar ones. If you would like to visualize and compare a different camera combination, you can navigate to the CAM-parator app and make your selection from a broad list of cameras there.
|1.||Canon T3i||133 mm||100 mm||80 mm||570 g||440||n||Feb 2011||599|
|2.||Pentax K-3||131 mm||100 mm||77 mm||800 g||560||Y||Oct 2013||1,299|
|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 70D||139 mm||104 mm||79 mm||755 g||920||Y||Jul 2013||1,199|
|7.||Canon SL1||117 mm||91 mm||69 mm||407 g||380||n||Mar 2013||549|
|8.||Canon T5i||133 mm||100 mm||79 mm||580 g||440||n||Mar 2013||649|
|9.||Canon M||109 mm||66 mm||32 mm||298 g||230||n||Jul 2012||599|
|10.||Canon T4i||133 mm||100 mm||79 mm||575 g||440||n||Jun 2012||849|
|11.||Canon T3||130 mm||100 mm||78 mm||495 g||700||n||Feb 2011||449|
|12.||Canon T2i||129 mm||98 mm||62 mm||530 g||440||n||Feb 2010||699|
|13.||Canon T1i||129 mm||98 mm||62 mm||520 g||400||n||Mar 2009||799|
|14.||Pentax KP||132 mm||101 mm||76 mm||703 g||390||Y||Jan 2017||1,099|
|15.||Pentax K-3 II||131 mm||100 mm||77 mm||800 g||720||Y||Apr 2015||1,099|
|16.||Pentax K-5 II||131 mm||97 mm||73 mm||760 g||740||Y||Sep 2012||1,099|
|17.||Pentax K-5||131 mm||97 mm||73 mm||760 g||740||Y||Sep 2010||1,099|
|Note: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.|
Any camera decision will obviously take relative prices into account. 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 T3i was launched at a markedly lower price (by 54 percent) than the K-3, 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 more expensive and lead to bigger and heavier cameras and lenses.
Both cameras under consideration feature an APS-C sensor, but their sensors differ slightly in size. The sensor area in the K-3 is 11 percent bigger. As a result of these sensor size differences, the cameras have format factors, respectively, of 1.6 (T3i) and 1.5. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.
In terms of underlying technology, both cameras are build around CMOS sensors.
With 24.1MP, the K-3 offers a higher resolution than the T3i (17.9MP), but the K-3 has smaller individual pixels (pixel pitch of 3.90μm versus 4.31μm for the T3i). Yet, the K-3 is a much more recent model (by 2 years and 7 months) than the T3i, and its sensor will have benefitted from technological advances during this time that enhance the light gathering capacity of its pixel-units. Coming back to sensor resolution, it should be mentioned that the K-3 has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.
The resolution advantage of the Pentax K-3 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the K-3 for good quality output (200 dots per inch) amounts to 30.1 x 20 inches or 76.4 x 50.8 cm, for very good quality (250 dpi) 24.1 x 16 inches or 61.1 x 40.6 cm, and for excellent quality (300 dpi) 20.1 x 13.3 inches or 50.9 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 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 Pentax K-3 are ISO 100 to ISO 51200 (no boost).
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 K-3 offers substantially better image quality than the T3i (overall score 15 points higher). The advantage is based on 1.6 bits higher color depth, 1.9 EV in additional dynamic range, and 0.6 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.
|15.||Pentax K-3 II||APS-C||24.1||6016||4000||1080/60i||23.6||13.6||1106||80|
|16.||Pentax K-5 II||APS-C||16.1||4928||3264||1080/25p||23.8||14.1||1235||82|
|Note: DXO values in italics represent estimates based on sensor size and age.|
Many modern cameras are not only capable of taking still images, but can also record movies. The two cameras under consideration both have sensors whose read-out speed is fast enough to capture moving pictures, but the K-3 provides a faster frame rate than the T3i. It can shoot movie footage at 1080/60i, while the Canon is limited to 1080/30p.
Beyond body and sensor, cameras can and do differ across a range of features. The T3i and the K-3 are similar in the sense that both have an optical viewfinder. The latter is useful for getting a clear image for framing even in brightly lit environments. The viewfinder in the K-3 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 K-3 has a higher magnification (0.63x vs 0.53x), so that the size of the image transmitted appears closer to the size seen with the naked human eye. The adjacent table lists some of the other core features of the Canon T3i and Pentax K-3 along with similar information for a selection of comparators.
|1.||Canon T3i||optical||n||3.0 / 1040||swivel||n||1/4000s||3.7/s||Y||n|
|2.||Pentax K-3||optical||Y||3.2 / 1037||fixed||n||1/8000s||8.3/s||Y||Y|
|3.||Canon SL2||optical||n||3.0 / 1040||swivel||Y||1/4000s||5.0/s||Y||n|
|4.||Canon T6s||optical||Y||3.0 / 1040||swivel||Y||1/4000s||5.0/s||Y||n|
|5.||Canon T5||optical||n||3.0 / 460||fixed||n||1/4000s||3.0/s||Y||n|
|6.||Canon 70D||optical||Y||3.0 / 1040||swivel||Y||1/8000s||7.0/s||Y||n|
|7.||Canon SL1||optical||n||3.0 / 1040||fixed||Y||1/4000s||4.9/s||Y||n|
|8.||Canon T5i||optical||n||3.0 / 1040||swivel||Y||1/4000s||5.0/s||Y||n|
|9.||Canon M||none||n||3.0 / 1040||fixed||Y||1/4000s||4.3/s||n||n|
|10.||Canon T4i||optical||n||3.0 / 1040||swivel||Y||1/4000s||5.0/s||Y||n|
|11.||Canon T3||optical||n||2.7 / 230||fixed||n||1/4000s||3.0/s||Y||n|
|12.||Canon T2i||optical||n||3.0 / 1040||fixed||n||1/4000s||3.7/s||Y||n|
|13.||Canon T1i||optical||n||3.0 / 920||fixed||n||1/4000s||3.4/s||Y||n|
|14.||Pentax KP||optical||n||3.0 / 921||tilting||n||1/6000s||7.0/s||Y||Y|
|15.||Pentax K-3 II||optical||Y||3.2 / 1037||fixed||n||1/8000s||8.3/s||n||Y|
|16.||Pentax K-5 II||optical||Y||3.0 / 921||fixed||n||1/8000s||7.0/s||Y||Y|
|17.||Pentax K-5||optical||Y||3.0 / 921||fixed||n||1/8000s||7.0/s||Y||Y|
|Notes: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.|
One feature that differentiates the K-3 and the T3i is in-body image stabilization (IBIS). The K-3 reduces the risk of handshake-induced blur with all attached lenses, while the T3i offers no blur reduction with lenses that themselves do not provide optical image stabilization.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 K-3 does not have a selfie-screen.
The Pentax K-3 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.
Concerning the storage of imaging data, both the T3i and the K-3 write their files to SDXC cards. The K-3 features dual card slots, which can be very useful in case a memory card fails. In contrast, the T3i only has one slot. The K-3 supports UHS-I cards (Ultra High Speed data transfer of up to 104 MB/s), 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 Pentax K-3 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
Mic / Speaker
|1.||Canon T3i||Y||mono / mono||Y||-||mini||2.0||-||-||-|
|2.||Pentax K-3||Y||mono / mono||Y||Y||mini||3.0||-||-||-|
|3.||Canon SL2||Y||stereo / mono||Y||-||mini||2.0||Y||Y||Y|
|4.||Canon T6s||Y||stereo / mono||Y||-||mini||2.0||Y||Y||-|
|5.||Canon T5||Y||mono / mono||-||-||mini||2.0||-||-||-|
|6.||Canon 70D||Y||stereo / mono||Y||-||mini||2.0||Y||-||-|
|7.||Canon SL1||Y||mono / mono||Y||-||mini||2.0||-||-||-|
|8.||Canon T5i||Y||stereo / mono||Y||-||mini||2.0||-||-||-|
|9.||Canon M||Y||stereo / mono||Y||-||mini||2.0||-||-||-|
|10.||Canon T4i||Y||stereo / mono||Y||-||mini||2.0||-||-||-|
|11.||Canon T3||Y||stereo / mono||-||-||mini||2.0||-||-||-|
|12.||Canon T2i||Y||stereo / -||Y||-||mini||2.0||-||-||-|
|13.||Canon T1i||Y||mono / mono||-||-||mini||2.0||-||-||-|
|14.||Pentax KP||Y||stereo / mono||Y||-||-||2.0||Y||-||-|
|15.||Pentax K-3 II||Y||mono / mono||Y||Y||mini||3.0||-||-||-|
|16.||Pentax K-5 II||Y||stereo / mono||Y||-||mini||2.0||-||-||-|
|17.||Pentax K-5||Y||stereo / mono||Y||-||mini||2.0||-||-||-|
It is notable that the K-3 has a headphone jack, which makes it possible to attach external headphones and monitor the quality of sound during the recording process. The T3i lacks such a headphone port.
Studio photographers will appreciate that the Pentax K-3 (unlike the T3i) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
Both the T3i and the K-3 have been discontinued, but can regularly be found used on eBay. The T3i was replaced by the Canon T4i, while the K-3 was followed by the Pentax K-3 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 Pentax websites.
So what conclusions can be drawn? Is the Canon T3i better than the Pentax K-3 or vice versa? The listing below highlights the relative strengths of the two models.
Arguments in favor of the Canon EOS Rebel T3i:
- Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
- 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 230g or 29 percent) and hence easier to carry around.
- More affordable: Was introduced into a lower priced category (54 percent cheaper at launch).
- More heavily discounted: Has been available for much longer (launched in February 2011).
Advantages of the Pentax K-3:
- More detail: Has more megapixels (24.1 vs 17.9MP), which boosts linear resolution by 16%.
- Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
- Better image quality: Scores substantially higher (15 points) in the DXO overall evaluation.
- Richer colors: Generates noticeably more natural colors (1.6 bits more color depth).
- More dynamic range: Captures a broader range of light and dark details (1.9 EV of extra DR).
- Better low-light sensitivity: Can shoot in dim conditions (0.6 stops ISO advantage).
- Better video: Provides higher movie framerates (1080/60i versus 1080/30p).
- Better sound control: Has a headphone port that enables audio monitoring while recording.
- 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 (0.63x vs 0.53x).
- Easier setting verification: Features a control panel on top to check shooting parameters.
- Larger screen: Has a bigger rear LCD (3.2" vs 3.0") for image review and settings control.
- Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
- Faster burst: Shoots at higher frequency (8.3 vs 3.7 flaps/sec) to capture the decisive moment.
- Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
- Longer lasting: Gets more shots (560 versus 440) 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.
- Faster data transfer: Supports a more advanced USB protocol (3.0 vs 2.0).
- 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: Has an SD card interface that supports the UHS-I standard.
- More modern: Reflects 2 years and 7 months of technical progress since the T3i launch.
If the count of relative strengths (bullet points above) is taken as a measure, the K-3 is the clear winner of the contest (23 : 6 points). However, the pertinence of the various camera strengths will differ across photographers, so that you might want to weigh individual camera traits according to their importance for your own imaging needs before making a camera decision. 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 Canon T3i and the Pentax K-3 place the cameras among the top in their class? Find out in the latest Best DSLR 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 partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the T3i or the K-3. 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.
This is why expert reviews are important. The table below provides a synthesis of the camera assessments of some of the best known photo-gear 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.
|1.||Canon T3i||3/5||o||..||77/100||4.5/5||4.5/5||Feb 2011||599|
|2.||Pentax K-3||4/5||..||..||83/100||5/5||5/5||Oct 2013||1,299|
|3.||Canon SL2||4/5||+ +||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 70D||5/5||+ +||..||83/100||4.5/5||5/5||Jul 2013||1,199|
|7.||Canon SL1||4/5||+||..||78/100||4/5||4/5||Mar 2013||549|
|8.||Canon T5i||..||..||..||76/100||4.5/5||4.5/5||Mar 2013||649|
|9.||Canon M||3/5||+||..||..||4/5||4/5||Jul 2012||599|
|10.||Canon T4i||4/5||+ +||..||77/100||4.5/5||4.5/5||Jun 2012||849|
|11.||Canon T3||..||80/100||..||69/100||4/5||4.5/5||Feb 2011||449|
|12.||Canon T2i||..||+ +||..||77/100||4/5||4.5/5||Feb 2010||699|
|13.||Canon T1i||..||+ +||..||74/100||4.5/5||4.5/5||Mar 2009||799|
|14.||Pentax KP||4/5||..||3/5||82/100||5/5||4.5/5||Jan 2017||1,099|
|15.||Pentax K-3 II||4.5/5||..||..||..||5/5||5/5||Apr 2015||1,099|
|16.||Pentax K-5 II||5/5||..||..||80/100||5/5||4.5/5||Sep 2012||1,099|
|17.||Pentax K-5||4/5||..||..||83/100||5/5||4.5/5||Sep 2010||1,099|
|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. 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. 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? 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.
- Canon 5DS R vs Canon T3i
- Canon G1 X Mark II vs Pentax K-3
- Canon SX540 vs Pentax K-3
- Canon T3i vs Fujifilm X-T4
- Canon T3i vs Nikon Df
- Canon T3i vs Sony A7 II
- Canon T3i vs Sony NEX-3N
- Canon T3i vs Sony WX800
- Nikon D500 vs Pentax K-3
- Nikon D7200 vs Pentax K-3
- Panasonic ZS70 vs Pentax K-3
- Pentax K-3 vs Sony A7S II
Specifications: Canon T3i vs Pentax K-3
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||Pentax K-3|
|Camera Type||Digital single lens reflex||Digital single lens reflex|
|Camera Lens||Canon EF mount lenses||Pentax K mount lenses|
|Launch Date||February 2011||October 2013|
|Launch Price||USD 599||USD 1,299|
|Sensor Specs||Canon T3i||Pentax K-3|
|Sensor Format||APS-C Sensor||APS-C Sensor|
|Sensor Size||22.3 x 14.9 mm||23.5 x 15.6 mm|
|Sensor Area||332.27 mm2||366.6 mm2|
|Sensor Diagonal||26.8 mm||28.2 mm|
|Sensor Resolution||17.9 Megapixels||24.1 Megapixels|
|Image Resolution||5184 x 3456 pixels||6016 x 4000 pixels|
|Pixel Pitch||4.31 μm||3.90 μm|
|Pixel Density||5.39 MP/cm2||6.56 MP/cm2|
|Moiré control||Anti-Alias filter||no AA filter|
|Movie Capability||1080/30p Video||1080/60i Video|
|ISO Setting||100 - 6,400 ISO||100 - 51,200 ISO|
|ISO Boost||100 - 12,800 ISO||no Enhancement|
|Image Processor||DIGIC 4||PRIME III|
|DXO Sensor Quality (score)||65||80|
|DXO Color Depth (bits)||22.1||23.7|
|DXO Dynamic Range (EV)||11.5||13.4|
|DXO Low Light (ISO)||793||1216|
|Screen Specs||Canon T3i||Pentax K-3|
|Viewfinder Type||Optical viewfinder||Optical viewfinder|
|Viewfinder Field of View||95%||100%|
|Top-Level Screen||no Top Display||Control Panel|
|LCD Framing||Live View||Live View|
|Rear LCD Size||3.0inch||3.2inch|
|LCD Resolution||1040k dots||1037k dots|
|LCD Attachment||Swivel screen||Fixed screen|
|Shooting Specs||Canon T3i||Pentax K-3|
|Focus System||Phase-detect AF||Phase-detect AF|
|Manual Focusing Aid||no Peaking Feature||Focus Peaking|
|Max Shutter Speed (mechanical)||1/4000s||1/8000s|
|Continuous Shooting||3.7 shutter flaps/s||8.3 shutter flaps/s|
|Shutter Life Expectancy||100 000 actuations||200 000 actuations|
|Time-Lapse Photography||no Intervalometer||Intervalometer built-in|
|Image Stabilization||Lens stabilization only||In-body stabilization|
|Fill Flash||Built-in Flash||Built-in Flash|
|Storage Medium||SDXC cards||SDXC cards|
|Second Storage Option||Single card slot||Dual card slots|
|UHS card support||no||UHS-I|
|Connectivity Specs||Canon T3i||Pentax K-3|
|Studio Flash||no PC Sync||PC Sync socket|
|USB Connector||USB 2.0||USB 3.0|
|HDMI Port||mini HDMI||mini HDMI|
|Microphone Port||External MIC port||External MIC port|
|Headphone Socket||no Headphone port||Headphone port|
|Wifi Support||no Wifi||no Wifi|
|Body Specs||Canon T3i||Pentax K-3|
|Environmental Sealing||not weather sealed||Weathersealed body|
|Battery Life (CIPA)||440 shots per charge||560 shots per charge|
133 x 100 x 80 mm
(5.2 x 3.9 x 3.1 in)
131 x 100 x 77 mm
(5.2 x 3.9 x 3.0 in)
|Camera Weight||570 g (20.1 oz)||800 g (28.2 oz)|
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