Canon XSi vs Pentax K-3
The Canon EOS Rebel XSi (called Canon 450D in some regions) and the Pentax K-3 are two digital cameras that were officially introduced, respectively, in January 2008 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 12.2 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 XSi 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 side-by-side display below illustrates the physical size and weight of the Canon XSi and the Pentax K-3. 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 dimensions are rounded to the nearest millimeter.
The K-3 can be obtained in two different colors (black, silver), while the XSi 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 larger (4 percent) than the Canon XSi. Moreover, the K-3 is substantially heavier (53 percent) than the XSi. It is noteworthy in this context that the K-3 is splash and dust-proof, while the XSi 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 XSi||129 mm||98 mm||62 mm||524 g||500||n||Jan 2008||799|
|2.||Pentax K-3||131 mm||100 mm||77 mm||800 g||560||Y||Oct 2013||1,299|
|3.||Canon T6i||132 mm||101 mm||78 mm||555 g||440||n||Feb 2015||749|
|4.||Canon T6s||132 mm||101 mm||78 mm||565 g||440||n||Feb 2015||649|
|5.||Canon T4i||133 mm||100 mm||79 mm||575 g||440||n||Jun 2012||849|
|6.||Canon T3||130 mm||100 mm||78 mm||495 g||700||n||Feb 2011||449|
|7.||Canon T2i||129 mm||98 mm||62 mm||530 g||440||n||Feb 2010||699|
|8.||Canon T1i||129 mm||98 mm||62 mm||520 g||400||n||Mar 2009||799|
|9.||Canon XS||126 mm||98 mm||65 mm||502 g||500||n||Jun 2008||449|
|10.||Canon 40D||146 mm||108 mm||74 mm||822 g||750||n||Aug 2007||1,299|
|11.||Canon XTi||127 mm||84 mm||65 mm||556 g||370||n||Aug 2006||799|
|12.||Canon XT||127 mm||94 mm||64 mm||540 g||400||n||Feb 2005||899|
|13.||Nikon D7100||136 mm||107 mm||76 mm||765 g||950||Y||Feb 2013||1,199|
|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.||Sony A77||143 mm||104 mm||81 mm||732 g||470||Y||Aug 2011||1,399|
|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 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 XSi was launched at a markedly lower price (by 38 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. 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. 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 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 12 percent bigger. As a result of these sensor size differences, the cameras have format factors, respectively, of 1.6 (XSi) 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 XSi (12.2MP), but the K-3 has smaller individual pixels (pixel pitch of 3.90μm versus 5.19μm for the XSi). Yet, the K-3 is a much more recent model (by 5 years and 8 months) than the XSi, 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 XSi are 21.4 x 14.2 inches or 54.3 x 36.2 cm for good quality, 17.1 x 11.4 inches or 43.4 x 28.9 cm for very good quality, and 14.2 x 9.5 inches or 36.2 x 24.1 cm for excellent quality prints.
The Canon EOS Rebel XSi has a native sensitivity range from ISO 100 to ISO 1600. The corresponding ISO settings for the Pentax K-3 are ISO 100 to ISO 51200 (no boost).
Consistent information on actual sensor performance is available from DXO Mark for many cameras. 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 K-3 offers substantially better image quality than the XSi (overall score 19 points higher). The advantage is based on 1.8 bits higher color depth, 2.6 EV in additional dynamic range, and 0.8 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 |
|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|
Many modern cameras are not only capable of taking still images, but can also record movies. The K-3 indeed provides for movie recording, while the XSi does not. The highest resolution format that the K-3 can use is 1080/60i.
Apart from body and sensor, cameras can and do differ across a range of features. The XSi 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 XSi (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 0.54x), 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 XSi, the Pentax K-3, and comparable cameras.
|15.||Pentax K-3 II||optical||Y||3.2||1037||fixed||n||1/8000s||8.3||n||Y|
|16.||Pentax K-5 II||optical||Y||3.0||921||fixed||n||1/8000s||7.0||Y||Y|
One feature that differentiates the K-3 and the XSi is in-body image stabilization (IBIS). The K-3 reduces the risk of handshake-induced blur with all attached lenses, while the XSi offers no blur reduction with lenses that themselves do not provide optical image stabilization.
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.
The XSi writes its imaging data to SDHC cards, while the K-3 uses SDXC cards. The K-3 features dual card slots, which can be very useful in case a memory card fails. In contrast, the XSi only has one slot. The K-3 supports UHS-I cards (Ultra High Speed data transfer of up to 104 MB/s), while the XSi 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 XSi and Pentax K-3 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.
| WiFi |
| NFC |
|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||-||-||-|
Studio photographers will appreciate that the Pentax K-3 (unlike the XSi) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.
Both the XSi and the K-3 have been discontinued, but can regularly be found used on eBay. The XSi was replaced by the Canon T1i, 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? Which of the two cameras – the Canon XSi or the Pentax K-3 – has the upper hand? Is one clearly better than the other? Below is a summary of the relative strengths of each of the two contestants.
Reasons to prefer the Canon EOS Rebel XSi:
- Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
- Less heavy: Is lighter (by 276g or 34 percent) and hence easier to carry around.
- More affordable: Was introduced into a lower priced category (38 percent cheaper at launch).
- More heavily discounted: Has been available for much longer (launched in January 2008).
Arguments in favor of the Pentax K-3:
- More detail: Has more megapixels (24.1 vs 12.2MP), which boosts linear resolution by 41%.
- Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
- Better image quality: Scores substantially higher (19 points) in the DXO overall evaluation.
- Richer colors: Generates noticeably more natural colors (1.8 bits more color depth).
- More dynamic range: Captures a broader range of light and dark details (2.6 EV of extra DR).
- Better low-light sensitivity: Can shoot in dim conditions (0.8 stops ISO advantage).
- Broader imaging potential: Can capture not only stills but also 1080/60i video.
- 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 0.54x).
- 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.
- More detailed LCD: Has a higher resolution rear screen (1037k vs 230k dots).
- Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
- Faster burst: Shoots at higher frequency (8.3 vs 3.5 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 500) 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 5 years and 8 months of technical progress since the XSi launch.
If the number of relative strengths (bullet points above) is taken as a guide, the K-3 is the clear winner of the contest (23 : 4 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 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 XSi 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 specs-based evaluation of cameras can be instructive in revealing their potential as photographic tools, it remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the XSi 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], 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 XSi||..||+ +||+ +||4/5||4.5/5||Jan 2008||799|
|2.||Pentax K-3||4/5||..||83/100||5/5||5/5||Oct 2013||1,299|
|3.||Canon T6i||5/5||..||75/100||4.5/5||4.5/5||Feb 2015||749|
|4.||Canon T6s||5/5||+||77/100||4.5/5||4.5/5||Feb 2015||649|
|5.||Canon T4i||4/5||+ +||77/100||4.5/5||4.5/5||Jun 2012||849|
|6.||Canon T3||..||80/100||69/100||4/5||4.5/5||Feb 2011||449|
|7.||Canon T2i||..||+ +||77/100||4/5||4.5/5||Feb 2010||699|
|8.||Canon T1i||..||+ +||74/100||4.5/5||4.5/5||Mar 2009||799|
|9.||Canon XS||..||82/100||+ +||3.5/5||4.5/5||Jun 2008||449|
|10.||Canon 40D||..||+ +||+ +||4.5/5||4.5/5||Aug 2007||1,299|
|11.||Canon XTi||..||+ +||+ +||o||4/5||Aug 2006||799|
|12.||Canon XT||..||80/100||+ +||o||..||Feb 2005||899|
|13.||Nikon D7100||5/5||+ +||85/100||4.5/5||4.5/5||Feb 2013||1,199|
|14.||Pentax KP||4/5||..||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.||Sony A77||5/5||91/100||81/100||..||5/5||Aug 2011||1,399|
|Notes: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.|
Care should be taken when interpreting the review scores above, though. The assessments were made in relation to similar cameras of the same technological generation. 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. 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. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.
Specifications: Canon XSi 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 XSi||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||January 2008||October 2013|
|Launch Price||USD 799||USD 1,299|
|Sensor Specs||Canon XSi||Pentax K-3|
|Sensor Format||APS-C Sensor||APS-C Sensor|
|Sensor Size||22.2 x 14.8 mm||23.5 x 15.6 mm|
|Sensor Area||328.56 mm2||366.6 mm2|
|Sensor Diagonal||26.7 mm||28.2 mm|
|Sensor Resolution||12.2 Megapixels||24.1 Megapixels|
|Image Resolution||4272 x 2848 pixels||6016 x 4000 pixels|
|Pixel Pitch||5.19 μm||3.90 μm|
|Pixel Density||3.70 MP/cm2||6.56 MP/cm2|
|Moiré control||Anti-Alias filter||no AA filter|
|Movie Capability||no Video||1080/60i Video|
|ISO Setting||100 - 1,600 ISO||100 - 51,200 ISO|
|Image Processor||DIGIC 3||PRIME III|
|DXO Sensor Quality (score)||61||80|
|DXO Color Depth (bits)||21.9||23.7|
|DXO Dynamic Range (EV)||10.8||13.4|
|DXO Low Light (ISO)||692||1216|
|Screen Specs||Canon XSi||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||230k dots||1037k dots|
|LCD Attachment||Fixed screen||Fixed screen|
|Shooting Specs||Canon XSi||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||3.5 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||Build-in Flash||Build-in Flash|
|Storage Medium||SDHC cards||SDXC cards|
|Second Storage Option||Single card slot||Dual card slots|
|UHS card support||no||UHS-I|
|Connectivity Specs||Canon XSi||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||no MIC socket||External MIC port|
|Headphone Socket||no Headphone port||Headphone port|
|Wifi Support||no Wifi||no Wifi|
|Body Specs||Canon XSi||Pentax K-3|
|Environmental Sealing||not weather sealed||Weathersealed body|
|Battery Life (CIPA)||500 shots per charge||560 shots per charge|
129 x 98 x 62 mm
(5.1 x 3.9 x 2.4 in)
131 x 100 x 77 mm
(5.2 x 3.9 x 3.0 in)
|Camera Weight||524 g (18.5 oz)||800 g (28.2 oz)|
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