Canon 850D vs Pentax K-S1

The Canon EOS 850D (called Canon T8i in some regions) and the Pentax K-S1 are two digital cameras that were announced, respectively, in February 2020 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 850D		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
4K/24p Video		1080/30p Video
ISO 100-25,600 (100 - 51,200)		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)
7.5 shutter flaps per second		5.4 shutter flaps per second
Lens stabilization only		In-body stabilization
800 shots per battery charge		410 shots per battery charge
131 x 103 x 76 mm, 515 g		121 x 93 x 70 mm, 558 g

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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 850D 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 physical size and weight of the Canon 850D and the Pentax K-S1 are illustrated in the side-by-side display below. The two cameras are presented according to their relative size. Three consecutive perspectives from the front, the top, and the back are available. 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 850D 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 (17 percent) than the Canon 850D. However, the K-S1 is markedly heavier (8 percent) than the 850D. In this context, it is worth noting that neither the 850D 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 850D gets 800 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. In case you want to display and compare another camera duo, you can use the CAM-parator app to select your camera combination among a large number of options.

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 850D	131 mm	103 mm	76 mm	515 g	800	n	Feb 2020	749	ebay.com
2.		Pentax K-S1	121 mm	93 mm	70 mm	558 g	410	n	Aug 2014	749	ebay.com
3.		Canon RP	133 mm	85 mm	70 mm	485 g	250	n	Feb 2019	1,299	amazon.com
4.		Canon 250D	122 mm	93 mm	70 mm	449 g	1070	n	Apr 2019	599	amazon.com
5.		Canon G5 X Mark II	111 mm	61 mm	46 mm	340 g	230	n	Jul 2019	899	ebay.com
6.		Canon G7 X Mark III	105 mm	61 mm	41 mm	304 g	235	n	Jul 2019	749	amazon.com
7.		Canon 2000D	129 mm	101 mm	78 mm	475 g	500	n	Feb 2018	449	amazon.com
8.		Canon 77D	131 mm	100 mm	76 mm	540 g	600	n	Feb 2017	899	ebay.com
9.		Canon 200D	122 mm	93 mm	70 mm	453 g	650	n	Jun 2017	549	ebay.com
10.		Canon 800D	131 mm	100 mm	76 mm	532 g	600	n	Feb 2017	749	ebay.com
11.		Canon 750D	132 mm	101 mm	78 mm	555 g	440	n	Feb 2015	749	ebay.com
12.		Canon 760D	132 mm	101 mm	78 mm	565 g	440	n	Feb 2015	649	ebay.com
13.		Nikon D5300	125 mm	98 mm	76 mm	480 g	600	n	Oct 2013	799	ebay.com
14.		Pentax K-S2	123 mm	91 mm	73 mm	678 g	410	Y	Feb 2015	749	ebay.com
15.		Pentax K-500	130 mm	97 mm	71 mm	646 g	710	n	Jun 2013	549	ebay.com
16.		Pentax K-3	131 mm	100 mm	77 mm	800 g	560	Y	Oct 2013	1,299	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

The price is, of course, an important factor in any camera decision. 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 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 sensor inside a digital camera is one of the key determinants 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 tend to be associated with larger, more expensive camera bodies 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 (850D) 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 850D 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 850D is much more recent (by 5 years and 5 months) than the K-S1, and its sensor will have benefitted from technological advances during this time that make it possible to gather light more efficiently. 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 850D implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the 850D 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 850D has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.

The Canon EOS 850D has a native sensitivity range from ISO 100 to ISO 25600, which can be extended to ISO 100-51200. 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.

Since 2007, DXO Mark has published sensor performance measurements that have been derived using a consistent methodology. This service assesses and scores the color depth ("DXO Portrait"), dynamic range ("DXO Landscape"), and low-light sensitivity ("DXO Sports") of camera sensors, and also publishes an overall camera score. 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 850D	APS-C	24.0	6000	4000	4K/24p	24.0	13.5	1873	83
2.		Pentax K-S1	APS-C	20.0	5472	3648	1080/30p	23.5	13.0	1061	78
3.		Canon RP	Full Frame	26.0	6240	4160	4K/30p	24.3	11.9	2977	85
4.		Canon 250D	APS-C	24.0	6000	4000	4K/25p	23.9	13.4	1791	82
5.		Canon G5 X Mark II	1-inch	20.0	5472	3648	4K/30p	22.2	12.4	583	65
6.		Canon G7 X Mark III	1-inch	20.0	5472	3648	4K/30p	22.2	12.4	583	65
7.		Canon 2000D	APS-C	24.0	6000	4000	1080/30p	22.6	11.9	1009	71
8.		Canon 77D	APS-C	24.0	6000	4000	1080/60p	23.6	13.3	971	78
9.		Canon 200D	APS-C	24.0	6000	4000	1080/60p	23.6	13.4	1041	79
10.		Canon 800D	APS-C	24.0	6000	4000	1080/60p	23.7	13.1	1586	80
11.		Canon 750D	APS-C	24.0	6000	4000	1080/30p	22.7	12.0	919	71
12.		Canon 760D	APS-C	24.0	6000	4000	1080/30p	22.6	12.0	915	70
13.		Nikon D5300	APS-C	24.0	6000	4000	1080/60p	24.0	13.9	1338	83
14.		Pentax K-S2	APS-C	20.0	5472	3648	1080/30p	23.6	12.9	1514	79
15.		Pentax K-500	APS-C	16.1	4928	3264	1080/30p	23.7	13.1	1087	79
16.		Pentax K-3	APS-C	24.1	6016	4000	1080/60i	23.7	13.4	1216	80
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 cannot only take still pictures, but also record videos. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, but the 850D provides a higher video resolution than the K-S1. It can shoot video footage at 4K/24p, while the Pentax is limited to 1080/30p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. The 850D 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 850D (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 850D 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 850D	optical	n	3.0 / 1040	swivel	Y	1/4000s	7.5/s	Y	n
2.		Pentax K-S1	optical	n	3.0 / 921	fixed	n	1/6000s	5.4/s	Y	Y
3.		Canon RP	2360	n	3.0 / 1040	swivel	Y	1/4000s	5.0/s	n	n
4.		Canon 250D	optical	n	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
5.		Canon G5 X Mark II	2360	n	3.0 / 1040	tilting	Y	1/2000s	30/s	Y	Y
6.		Canon G7 X Mark III	none	n	3.0 / 1040	tilting	Y	1/2000s	30/s	Y	Y
7.		Canon 2000D	optical	n	3.0 / 920	fixed	n	1/4000s	3.0/s	Y	n
8.		Canon 77D	optical	Y	3.0 / 1040	swivel	Y	1/4000s	6.0/s	Y	n
9.		Canon 200D	optical	n	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
10.		Canon 800D	optical	n	3.0 / 1040	swivel	Y	1/4000s	6.0/s	Y	n
11.		Canon 750D	optical	n	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
12.		Canon 760D	optical	Y	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
13.		Nikon D5300	optical	n	3.2 / 1037	swivel	n	1/4000s	5.0/s	Y	n
14.		Pentax K-S2	optical	n	3.0 / 921	swivel	n	1/6000s	5.4/s	Y	Y
15.		Pentax K-500	optical	n	3.0 / 921	fixed	n	1/6000s	6.0/s	Y	Y
16.		Pentax K-3	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/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 850D has a touchscreen, while the K-S1 has a conventional panel. Touch control can be particularly helpful, for example, for setting the focus point.

The Canon 850D 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 850D 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 850D 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 850D	Y	stereo / mono	Y	-	mini	2.0	Y	-	Y
2.		Pentax K-S1	Y	stereo / mono	-	-	micro	2.0	-	-	-
3.		Canon RP	Y	stereo / mono	Y	Y	micro	2.0	Y	-	Y
4.		Canon 250D	Y	stereo / mono	Y	-	mini	2.0	Y	-	Y
5.		Canon G5 X Mark II	-	stereo / mono	-	-	micro	3.1	Y	-	Y
6.		Canon G7 X Mark III	-	stereo / mono	Y	-	micro	3.1	Y	-	Y
7.		Canon 2000D	Y	mono / mono	-	-	mini	2.0	Y	Y	-
8.		Canon 77D	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
9.		Canon 200D	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
10.		Canon 800D	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
11.		Canon 750D	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
12.		Canon 760D	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
13.		Nikon D5300	Y	stereo / mono	Y	-	mini	2.0	Y	-	-
14.		Pentax K-S2	Y	mono / mono	Y	-	micro	2.0	Y	Y	-
15.		Pentax K-500	Y	mono / mono	-	-	-	2.0	-	-	-
16.		Pentax K-3	Y	mono / mono	Y	Y	mini	3.0	-	-	-
17.		Sony A68	Y	stereo / mono	Y	-	micro	2.0	-	-	-

It is notable that the 850D 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 850D 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 850D does not have a direct successor. Further information on the features and operation of the 850D and K-S1 can be found, respectively, in the Canon 850D Manual (free pdf) or the online Pentax K-S1 Manual.

Review summary

So what conclusions can be drawn? Is there a clear favorite between the Canon 850D and the Pentax K-S1? Which camera is better? Below is a summary of the relative strengths of each of the two contestants.

Arguments in favor of the Canon EOS 850D:

• 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 video: Provides higher definition movie capture (4K/24p vs 1080/30p).
• 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.
• Faster burst: Shoots at higher frequency (7.5 vs 5.4 flaps/sec) to capture the decisive moment.
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• Longer lasting: Can take more shots (800 versus 410) on a single battery charge.
• Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
• Easier wireless transfer: Supports Bluetooth for image sharing without cables.
• More modern: Reflects 5 years and 5 months of technical progress since the K-S1 launch.

Advantages of the Pentax K-S1:

• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• 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 131x103mm) 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 around for much longer (launched in August 2014).

If the count of individual advantages (bullet points above) is taken as a guide, the 850D is the clear winner of the match-up (15 : 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 850D 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 comparison of the spec-sheets of cameras can offer a general idea of their imaging potential, it says little about, for example, the shooting experience and imaging performance of the 850D and the K-S1 in practical situations. 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.

Expert reviews

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], 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 850D	4/5	+	3/5	80/100	4/5	3.5/5	Feb 2020	749	ebay.com
2.		Pentax K-S1	4/5	..	..	..	4.5/5	4/5	Aug 2014	749	ebay.com
3.		Canon RP	4/5	+	4/5	..	4.5/5	4/5	Feb 2019	1,299	amazon.com
4.		Canon 250D	4/5	o	4.5/5	79/100	4/5	4/5	Apr 2019	599	amazon.com
5.		Canon G5 X Mark II	4/5	+	4/5	82/100	..	4/5	Jul 2019	899	ebay.com
6.		Canon G7 X Mark III	..	+ +	4/5	81/100	4/5	..	Jul 2019	749	amazon.com
7.		Canon 2000D	3/5	o	3.5/5	..	3.5/5	3.5/5	Feb 2018	449	amazon.com
8.		Canon 77D	4.5/5	..	4/5	82/100	4.5/5	4/5	Feb 2017	899	ebay.com
9.		Canon 200D	4/5	+ +	4/5	78/100	4.5/5	4.5/5	Jun 2017	549	ebay.com
10.		Canon 800D	4.5/5	..	3.5/5	80/100	4.5/5	4/5	Feb 2017	749	ebay.com
11.		Canon 750D	5/5	..	..	75/100	4.5/5	4.5/5	Feb 2015	749	ebay.com
12.		Canon 760D	5/5	+	..	77/100	4.5/5	4.5/5	Feb 2015	649	ebay.com
13.		Nikon D5300	4/5	+ +	..	79/100	4.5/5	4.5/5	Oct 2013	799	ebay.com
14.		Pentax K-S2	4.5/5	..	..	..	5/5	4.5/5	Feb 2015	749	ebay.com
15.		Pentax K-500	..	..	..	..	4.5/5	4.5/5	Jun 2013	549	ebay.com
16.		Pentax K-3	4/5	..	..	83/100	5/5	5/5	Oct 2013	1,299	ebay.com
17.		Sony A68	3/5	..	..	..	4/5	4/5	Nov 2015	699	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

Care should be taken when interpreting the review scores above, 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 comparing ratings of very distinct cameras or ones that are far apart in terms of their release date have little meaning. Also, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.

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Other camera comparisons

Did this review help to inform your camera decision process? If you would like to see a different side-by-side camera review, 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.

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