Canon T6i vs Pentax K-S1

The Canon EOS Rebel T6i (called Canon 750D in some regions) and the Pentax K-S1 are two digital cameras that were revealed to the public, respectively, in February 2015 and August 2014. Both are DSLR (Digital Single Lens Reflex) cameras that are equipped with an APS-C sensor. The Canon has a resolution of 24 megapixels, whereas the Pentax provides 20 MP.

Below is an overview of the main specs of the two cameras as a starting point for the comparison.

Headline Specifications

Canon T6i		Pentax K-S1
Digital single lens reflex		Digital single lens reflex
Canon EF mount lenses		Pentax K mount lenses
24 MP – APS-C sensor		20 MP – APS-C sensor
1080/30p Video		1080/30p Video
ISO 100-12,800 (100 - 25,600)		ISO 100-51,200
Optical viewfinder		Optical viewfinder
3.0" LCD – 1040k dots		3.0" LCD – 921k dots
Swivel touchscreen		Fixed screen (not touch-sensitive)
5 shutter flaps per second		5.4 shutter flaps per second
Lens stabilization only		In-body stabilization
440 shots per battery charge		410 shots per battery charge
132 x 101 x 78 mm, 555 g		121 x 93 x 70 mm, 558 g

Check T6i offers at
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Check K-S1 offers at
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Going beyond this snapshot of core features and characteristics, what are the differences between the Canon EOS Rebel T6i and the Pentax K-S1? 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.

Body comparison

The side-by-side display below illustrates the physical size and weight of the Canon T6i and the Pentax K-S1. 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-S1 can be obtained in four different colors (black, grey, orange, white), while the T6i 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-S1 is notably smaller (16 percent) than the Canon T6i. However, the K-S1 is slightly heavier (1 percent) than the T6i. In this context, it is worth noting that neither the T6i nor the K-S1 are weather-sealed.

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.

Concerning battery life, the T6i gets 440 shots out of its Canon LP-E17 battery, while the K-S1 can take 410 images on a single charge of its Pentax D-LI109 power pack.

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.

Body Specifications

#		Camera Model	Camera Width	Camera Height	Camera Depth	Camera Weight	Battery Life	Weather Sealing	Camera Launch	Launch Price (USD)	Street Price
1.		Canon T6i	132 mm	101 mm	78 mm	555 g	440	n	Feb 2015	749	ebay.com
2.		Pentax K-S1	121 mm	93 mm	70 mm	558 g	410	n	Aug 2014	749	ebay.com
3.		Canon 77D	131 mm	100 mm	76 mm	540 g	600	n	Feb 2017	899	ebay.com
4.		Canon T7i	131 mm	100 mm	76 mm	532 g	600	n	Feb 2017	749	ebay.com
5.		Canon T6s	132 mm	101 mm	78 mm	565 g	440	n	Feb 2015	649	ebay.com
6.		Canon T5	130 mm	100 mm	78 mm	480 g	500	n	Feb 2014	449	ebay.com
7.		Canon T5i	133 mm	100 mm	79 mm	580 g	440	n	Mar 2013	649	ebay.com
8.		Canon T4i	133 mm	100 mm	79 mm	575 g	440	n	Jun 2012	849	ebay.com
9.		Canon T1i	129 mm	98 mm	62 mm	520 g	400	n	Mar 2009	799	ebay.com
10.		Canon XSi	129 mm	98 mm	62 mm	524 g	500	n	Jan 2008	799	ebay.com
11.		Canon XTi	127 mm	84 mm	65 mm	556 g	370	n	Aug 2006	799	ebay.com
12.		Canon XT	127 mm	94 mm	64 mm	540 g	400	n	Feb 2005	899	ebay.com
13.		Nikon D5500	124 mm	97 mm	70 mm	470 g	820	n	Jan 2015	899	ebay.com
14.		Nikon D5300	125 mm	98 mm	76 mm	480 g	600	n	Oct 2013	799	ebay.com
15.		Pentax K-S2	123 mm	91 mm	73 mm	678 g	410	Y	Feb 2015	749	ebay.com
16.		Pentax K-500	130 mm	97 mm	71 mm	646 g	710	n	Jun 2013	549	ebay.com
17.		Sony A68	143 mm	104 mm	81 mm	610 g	540	n	Nov 2015	699	ebay.com
Note: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.
Convert to Imperial

Any camera decision will naturally be influenced heavily by the price. The manufacturer’s suggested retail prices give an idea on the placement of the camera in the maker’s lineup and the broader market. The two cameras under review were launched at the same price and fall into the same market segment. Normally, street prices remain initially close to the MSRP, but after a couple of months, the first discounts appear. 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.

Sensor comparison

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. Furthermore, a large sensor camera will give the photographer more possibilities to use shallow depth-of-field in order to isolate a subject from the background. On the downside, larger sensors are more costly to manufacture and tend to 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-S1 is 11 percent bigger. As a result of these sensor size differences, the cameras have format factors, respectively, of 1.6 (T6i) and 1.5. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

Despite having a smaller sensor, the Canon T6i offers a higher resolution of 24 megapixels, compared with 20 MP of the Pentax K-S1. This megapixels advantage comes at the cost of a higher pixel density and a smaller size of the individual pixel (with a pixel pitch of 3.72μm versus 4.28μm for the K-S1). However, it should be noted that the T6i is a somewhat more recent model (by 5 months) than the K-S1, and its sensor might have benefitted from technological advances during this time that partly offset its pixel-size disadvantage. Coming back to sensor resolution, it should be mentioned that the K-S1 has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

The resolution advantage of the Canon T6i implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the T6i 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 Pentax K-S1 are 27.4 x 18.2 inches or 69.5 x 46.3 cm for good quality, 21.9 x 14.6 inches or 55.6 x 37.1 cm for very good quality, and 18.2 x 12.2 inches or 46.3 x 30.9 cm for excellent quality prints.

The T6i has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.

The Canon EOS Rebel T6i has a native sensitivity range from ISO 100 to ISO 12800, which can be extended to ISO 100-25600. The corresponding ISO settings for the Pentax K-S1 are ISO 100 to ISO 51200 (no boost).

Technology-wise, both cameras are equipped with CMOS (Complementary Metal–Oxide–Semiconductor) sensors. Both cameras use a Bayer filter for capturing RGB colors on a square grid of photosensors. This arrangement is found in most digital cameras.

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"). Of the two cameras under consideration, the K-S1 has a markedly higher DXO score than the T6i (overall score 7 points higher), which will translate into better image quality. The advantage is based on 0.8 bits higher color depth, 1 EV in additional dynamic range, and 0.2 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.

Sensor Characteristics

#		Camera Model	Sensor Class	Resolution (MP)	Horiz. Pixels	Vert. Pixels	Video Format	DXO Portrait	DXO Landscape	DXO Sports	DXO Overall
1.		Canon T6i	APS-C	24.0	6000	4000	1080/30p	22.7	12.0	919	71
2.		Pentax K-S1	APS-C	20.0	5472	3648	1080/30p	23.5	13.0	1061	78
3.		Canon 77D	APS-C	24.0	6000	4000	1080/60p	23.6	13.3	971	78
4.		Canon T7i	APS-C	24.0	6000	4000	1080/60p	23.7	13.1	1586	80
5.		Canon T6s	APS-C	24.0	6000	4000	1080/30p	22.6	12.0	915	70
6.		Canon T5	APS-C	17.9	5184	3456	1080/30p	21.9	11.3	724	63
7.		Canon T5i	APS-C	17.9	5184	3456	1080/30p	21.7	11.2	681	61
8.		Canon T4i	APS-C	17.9	5184	3456	1080/30p	21.7	11.2	722	62
9.		Canon T1i	APS-C	15.1	4752	3168	1080/20p	21.7	11.5	663	63
10.		Canon XSi	APS-C	12.2	4272	2848	none	21.9	10.8	692	61
11.		Canon XTi	APS-C	10.1	3888	2592	none	22.1	11.0	664	62
12.		Canon XT	APS-C	8.0	3456	2304	none	21.8	10.8	637	60
13.		Nikon D5500	APS-C	24.0	6000	4000	1080/60p	24.1	14.0	1438	84
14.		Nikon D5300	APS-C	24.0	6000	4000	1080/60p	24.0	13.9	1338	83
15.		Pentax K-S2	APS-C	20.0	5472	3648	1080/30p	23.6	12.9	1514	79
16.		Pentax K-500	APS-C	16.1	4928	3264	1080/30p	23.7	13.1	1087	79
17.		Sony A68	APS-C	24.0	6000	4000	1080/60i	24.1	13.5	701	79
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 also of capturing video footage. The two cameras under consideration both have sensors whose read-out speed is fast enough to capture moving pictures, and both provide the same movie specifications (1080/30p).

Feature comparison

Apart from body and sensor, cameras can and do differ across a range of features. The T6i and the K-S1 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-S1 offers a wider field of view (100%) than the one in the T6i (95%), so that a larger proportion of the captured image is visible in the finder. In addition, the viewfinder of the K-S1 has a higher magnification (0.63x vs 0.51x), 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 T6i and Pentax K-S1 along with similar information for a selection of comparators.

Core Features

#		Camera Model	Viewfinder (Type or 000 dots)	Control Panel (yes/no)	LCD Specifications (inch/000 dots)	LCD Attach- ment	Touch Screen (yes/no)	Max Shutter Speed *	Max Shutter Flaps *	Built-in Flash (yes/no)	Built-in Image Stab
1.		Canon T6i	optical	n	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
2.		Pentax K-S1	optical	n	3.0 / 921	fixed	n	1/6000s	5.4/s	Y	Y
3.		Canon 77D	optical	Y	3.0 / 1040	swivel	Y	1/4000s	6.0/s	Y	n
4.		Canon T7i	optical	n	3.0 / 1040	swivel	Y	1/4000s	6.0/s	Y	n
5.		Canon T6s	optical	Y	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
6.		Canon T5	optical	n	3.0 / 460	fixed	n	1/4000s	3.0/s	Y	n
7.		Canon T5i	optical	n	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
8.		Canon T4i	optical	n	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
9.		Canon T1i	optical	n	3.0 / 920	fixed	n	1/4000s	3.4/s	Y	n
10.		Canon XSi	optical	n	3.0 / 230	fixed	n	1/4000s	3.5/s	Y	n
11.		Canon XTi	optical	n	2.5 / 230	fixed	n	1/4000s	3.0/s	Y	n
12.		Canon XT	optical	n	1.8 / 115	fixed	n	1/4000s	3.0/s	Y	n
13.		Nikon D5500	optical	n	3.2 / 1037	swivel	Y	1/4000s	5.0/s	Y	n
14.		Nikon D5300	optical	n	3.2 / 1037	swivel	n	1/4000s	5.0/s	Y	n
15.		Pentax K-S2	optical	n	3.0 / 921	swivel	n	1/6000s	5.4/s	Y	Y
16.		Pentax K-500	optical	n	3.0 / 921	fixed	n	1/6000s	6.0/s	Y	Y
17.		Sony A68	1440	Y	2.7 / 460	tilting	n	1/4000s	8.0/s	Y	Y
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One differentiating feature between the two cameras concerns the touch sensitivity of the rear screen. The T6i has a touchscreen, while the K-S1 has a conventional panel. Touch control can be particularly helpful, for example, for setting the focus point.

Concerning the storage of imaging data, both the T6i and the K-S1 write their files to SDXC cards. Both cameras can use UHS-I cards, which provide for Ultra High Speed data transfer of up to 104 MB/s.

Connectivity comparison

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 T6i and Pentax K-S1 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.

Input-Output Connections

#		Camera Model	Hotshoe Port	Internal Mic / Speaker	Microphone Port	Headphone Port	HDMI Port	USB Port	WiFi Support	NFC Support	Bluetooth Support
1.		Canon T6i	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
2.		Pentax K-S1	Y	stereo / mono	-	-	micro	2.0	-	-	-
3.		Canon 77D	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
4.		Canon T7i	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
5.		Canon T6s	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
6.		Canon T5	Y	mono / mono	-	-	mini	2.0	-	-	-
7.		Canon T5i	Y	stereo / mono	Y	-	mini	2.0	-	-	-
8.		Canon T4i	Y	stereo / mono	Y	-	mini	2.0	-	-	-
9.		Canon T1i	Y	mono / mono	-	-	mini	2.0	-	-	-
10.		Canon XSi	Y	- / -	-	-	mini	2.0	-	-	-
11.		Canon XTi	Y	- / -	-	-	-	2.0	-	-	-
12.		Canon XT	Y	- / -	-	-	-	2.0	-	-	-
13.		Nikon D5500	Y	stereo / mono	Y	-	mini	2.0	Y	-	-
14.		Nikon D5300	Y	stereo / mono	Y	-	mini	2.0	Y	-	-
15.		Pentax K-S2	Y	mono / mono	Y	-	micro	2.0	Y	Y	-
16.		Pentax K-500	Y	mono / mono	-	-	-	2.0	-	-	-
17.		Sony A68	Y	stereo / mono	Y	-	micro	2.0	-	-	-

It is notable that the T6i has a microphone port, which is missing on the K-S1. Such an external microphone input can help to substantially improve the quality of audio recordings when a good external microphone is used.

Both the T6i and the K-S1 have been discontinued, but can regularly be found used on ebay. The K-S1 was replaced by the Pentax K-S2, while the T6i was followed by the Canon T7i. Further information on the features and operation of the T6i and K-S1 can be found, respectively, in the Canon T6i Manual (free pdf) or the online Pentax K-S1 Manual.

Review summary

So what conclusions can be drawn? Is the Canon T6i better than the Pentax K-S1 or vice versa? A synthesis of the relative strong points of each of the models is listed below.

Advantages of the Canon EOS Rebel T6i:

• More detail: Offers more megapixels (24 vs 20MP) with a 10% higher linear resolution.
• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• 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.
• More detailed LCD: Has a higher resolution rear screen (1040k vs 921k dots).
• More flexible LCD: Has a swivel screen for odd-angle shots in portrait or landscape orientation.
• Fewer buttons to press: Is equipped with a touch-sensitive rear screen to facilitate handling.
• More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
• 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.
• More modern: Is somewhat more recent (announced 5 months after the K-S1).

Arguments in favor of the Pentax K-S1:

• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• Better image quality: Scores markedly higher (7 points) in the DXO overall evaluation.
• More dynamic range: Captures a broader range of light and dark details (1 EV of extra DR).
• 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 0.51x).
• Faster shutter: Has higher mechanical shutter speed (1/6000s vs 1/4000s) to freeze action.
• More compact: Is smaller (121x93mm vs 132x101mm) and will fit more readily into a bag.
• Sharper images: Has stabilization technology built-in to reduce the impact of hand-shake.
• More heavily discounted: Has been on the market for longer (launched in August 2014).

If the count of individual advantages (bullet points above) is taken as a guide, the T6i emerges as the winner of the contest (11 : 9 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 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 Canon T6i and the Pentax K-S1 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 incomplete and does no justice, for example, to the way the T6i or the K-S1 perform in practice. User reviews, such as those found at amazon, can sometimes inform about these issues, but such feedback is often incomplete, inconsistent, and biased.

Expert reviews

This is why expert reviews are important. The following table reports the overall ratings of the cameras as published by some of the major camera 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.

Expert Camera Reviews

#		Camera   Model	AP   score	CL   score	DCW   score	DPR   score	EPZ   score	PB   score	Camera Launch	Launch Price (USD)	Street Price
1.		Canon T6i	5/5	..	..	75/100	4.5/5	4.5/5	Feb 2015	749	ebay.com
2.		Pentax K-S1	4/5	..	..	..	4.5/5	4/5	Aug 2014	749	ebay.com
3.		Canon 77D	4.5/5	..	4/5	82/100	4.5/5	4/5	Feb 2017	899	ebay.com
4.		Canon T7i	4.5/5	..	3.5/5	80/100	4.5/5	4/5	Feb 2017	749	ebay.com
5.		Canon T6s	5/5	+	..	77/100	4.5/5	4.5/5	Feb 2015	649	ebay.com
6.		Canon T5	3/5	+	..	..	4/5	4.5/5	Feb 2014	449	ebay.com
7.		Canon T5i	..	..	..	76/100	4.5/5	4.5/5	Mar 2013	649	ebay.com
8.		Canon T4i	4/5	+ +	..	77/100	4.5/5	4.5/5	Jun 2012	849	ebay.com
9.		Canon T1i	..	+ +	..	74/100	4.5/5	4.5/5	Mar 2009	799	ebay.com
10.		Canon XSi	..	+ +	..	+ +	4/5	4.5/5	Jan 2008	799	ebay.com
11.		Canon XTi	..	+ +	..	+ +	o	4/5	Aug 2006	799	ebay.com
12.		Canon XT	..	80/100	..	+ +	o	..	Feb 2005	899	ebay.com
13.		Nikon D5500	5/5	+	..	79/100	4.5/5	4.5/5	Jan 2015	899	ebay.com
14.		Nikon D5300	4/5	+ +	..	79/100	4.5/5	4.5/5	Oct 2013	799	ebay.com
15.		Pentax K-S2	4.5/5	..	..	..	5/5	4.5/5	Feb 2015	749	ebay.com
16.		Pentax K-500	..	..	..	..	4.5/5	4.5/5	Jun 2013	549	ebay.com
17.		Sony A68	3/5	..	..	..	4/5	4/5	Nov 2015	699	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The review scores listed above should be treated 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. A score, therefore, has to be seen in close connection to the price and market introduction time 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.

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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 make your choice using the following search menu. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.

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