Pentax K-S1 vs K-S2

The Pentax K-S1 and the Pentax K-S2 are two digital cameras that were announced, respectively, in August 2014 and February 2015. Both are DSLR (Digital Single Lens Reflex) cameras that are equipped with an APS-C sensor. Both cameras offer a resolution of 20 megapixels.

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

Headline Specifications

Pentax K-S1		Pentax K-S2
Digital single lens reflex		Digital single lens reflex
Pentax K mount lenses		Pentax K mount lenses
20 MP – APS-C sensor		20 MP – APS-C sensor
1080/30p Video		1080/30p Video
ISO 100-51,200		ISO 100-51,200
Optical viewfinder		Optical viewfinder
3.0" LCD – 921k dots		3.0" LCD – 921k dots
Fixed screen (not touch-sensitive)		Swivel screen (not touch-sensitive)
5.4 shutter flaps per second		5.4 shutter flaps per second
In-body stabilization		In-body stabilization
not weather sealed		Weathersealed body
410 shots per battery charge		410 shots per battery charge
121 x 93 x 70 mm, 558 g		123 x 91 x 73 mm, 678 g

Check K-S1 offers at
ebay.com
Check K-S2 offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Pentax K-S1 and the Pentax K-S2? 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

An illustration of the physical size and weight of the Pentax K-S1 and the Pentax K-S2 is provided in the side-by-side display below. The two cameras are presented according to their relative size. Three successive views from the front, the top, and the rear 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 K-S2 is available in six color-versions (black, grey, pink, orange, green, white).

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Pentax K-S1 and the Pentax K-S2 are of equal size. However, the K-S2 is markedly heavier (22 percent) than the K-S1. It is noteworthy in this context that the K-S2 is splash and dust-proof, while the K-S1 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 adjacent table lists the principal physical characteristics of the two cameras alongside a wider set of alternatives. 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.		Pentax K-S1	121 mm	93 mm	70 mm	558 g	410	n	Aug 2014	749	ebay.com
2.		Pentax K-S2	123 mm	91 mm	73 mm	678 g	410	Y	Feb 2015	749	ebay.com
3.		Canon 750D	132 mm	101 mm	78 mm	555 g	440	n	Feb 2015	749	ebay.com
4.		Canon 760D	132 mm	101 mm	78 mm	565 g	440	n	Feb 2015	649	ebay.com
5.		Nikon D5300	125 mm	98 mm	76 mm	480 g	600	n	Oct 2013	799	ebay.com
6.		Pentax KP	132 mm	101 mm	76 mm	703 g	390	Y	Jan 2017	1,099	ebay.com
7.		Pentax K-70	126 mm	93 mm	74 mm	688 g	410	Y	Jun 2016	649	ebay.com
8.		Pentax K-3 II	131 mm	100 mm	77 mm	800 g	720	Y	Apr 2015	1,099	ebay.com
9.		Pentax K-50	130 mm	97 mm	71 mm	650 g	410	Y	Jun 2013	599	ebay.com
10.		Pentax K-500	130 mm	97 mm	71 mm	646 g	710	n	Jun 2013	549	ebay.com
11.		Pentax K-3	131 mm	100 mm	77 mm	800 g	560	Y	Oct 2013	1,299	ebay.com
12.		Sony A68	143 mm	104 mm	81 mm	610 g	540	n	Nov 2015	699	ebay.com
13.		Sony A58	129 mm	95 mm	78 mm	492 g	690	n	Feb 2013	599	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 listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. 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.

Sensor comparison

The size of the imaging sensor is a crucial determinant of image quality. A large sensor will generally have larger individual pixels that offer better low-light sensitivity, provide wider dynamic range, and have richer color-depth than smaller pixels 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 and have a format factor (sometimes also referred to as "crop factor") of 1.5. Within the spectrum of camera sensors, this places the review cameras among the medium-sized sensor cameras that aim to strike a balance between image quality and portability. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

The two cameras under review do not only share the same sensor size, but also offer an identical resolution of 20 megapixels. This similarity in sensor specs implies that both the K-S1 and the K-S2 have the same pixel density, as well as the same pixel size. It should, however, be noted that the K-S2 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. Coming back to sensor resolution, it should be mentioned that neither of the two cameras has an anti-alias filter installed, so they are able to capture all the detail the sensor resolves.

The Pentax K-S1 has a native sensitivity range from ISO 100 to ISO 51200. The Pentax K-S2 offers exactly the same ISO settings.

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.

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"). The table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar cameras.

Sensor Characteristics

#		Camera Model	Sensor Class	Resolution (MP)	Horiz. Pixels	Vert. Pixels	Video Format	DXO Portrait	DXO Landscape	DXO Sports	DXO Overall
1.		Pentax K-S1	APS-C	20.0	5472	3648	1080/30p	23.5	13.0	1061	78
2.		Pentax K-S2	APS-C	20.0	5472	3648	1080/30p	23.6	12.9	1514	79
3.		Canon 750D	APS-C	24.0	6000	4000	1080/30p	22.7	12.0	919	71
4.		Canon 760D	APS-C	24.0	6000	4000	1080/30p	22.6	12.0	915	70
5.		Nikon D5300	APS-C	24.0	6000	4000	1080/60p	24.0	13.9	1338	83
6.		Pentax KP	APS-C	24.1	6016	4000	1080/60i	23.9	13.2	1699	81
7.		Pentax K-70	APS-C	24.0	6000	4000	1080/60i	23.8	13.1	1639	80
8.		Pentax K-3 II	APS-C	24.1	6016	4000	1080/60i	23.6	13.6	1106	80
9.		Pentax K-50	APS-C	16.1	4928	3264	1080/30p	23.7	13.0	1120	79
10.		Pentax K-500	APS-C	16.1	4928	3264	1080/30p	23.7	13.1	1087	79
11.		Pentax K-3	APS-C	24.1	6016	4000	1080/60i	23.7	13.4	1216	80
12.		Sony A68	APS-C	24.0	6000	4000	1080/60i	24.1	13.5	701	79
13.		Sony A58	APS-C	19.8	5456	3632	1080/60i	23.3	12.5	753	74
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 are equipped with sensors that have a sufficiently high read-out speed for moving images, and both provide the same movie specifications (1080/30p).

Feature comparison

Beyond body and sensor, cameras can and do differ across a range of features. The K-S1 and the K-S2 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 viewfinders of both cameras offer the same field of view (100%), as well as the same magnification (0.63x). The adjacent table lists some of the other core features of the Pentax K-S1 and Pentax K-S2 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.		Pentax K-S1	optical	n	3.0 / 921	fixed	n	1/6000s	5.4/s	Y	Y
2.		Pentax K-S2	optical	n	3.0 / 921	swivel	n	1/6000s	5.4/s	Y	Y
3.		Canon 750D	optical	n	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
4.		Canon 760D	optical	Y	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
5.		Nikon D5300	optical	n	3.2 / 1037	swivel	n	1/4000s	5.0/s	Y	n
6.		Pentax KP	optical	n	3.0 / 921	tilting	n	1/6000s	7.0/s	Y	Y
7.		Pentax K-70	optical	n	3.0 / 921	swivel	n	1/6000s	6.0/s	Y	Y
8.		Pentax K-3 II	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	n	Y
9.		Pentax K-50	optical	n	3.0 / 921	fixed	n	1/6000s	6.0/s	Y	Y
10.		Pentax K-500	optical	n	3.0 / 921	fixed	n	1/6000s	6.0/s	Y	Y
11.		Pentax K-3	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	Y	Y
12.		Sony A68	1440	Y	2.7 / 460	tilting	n	1/4000s	8.0/s	Y	Y
13.		Sony A58	1440	n	2.7 / 460	tilting	n	1/4000s	5.0/s	Y	Y
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

The Pentax K-S2 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 K-S1 and the K-S2 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 Pentax K-S1 and Pentax K-S2 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.		Pentax K-S1	Y	stereo / mono	-	-	micro	2.0	-	-	-
2.		Pentax K-S2	Y	mono / mono	Y	-	micro	2.0	Y	Y	-
3.		Canon 750D	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
4.		Canon 760D	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
5.		Nikon D5300	Y	stereo / mono	Y	-	mini	2.0	Y	-	-
6.		Pentax KP	Y	stereo / mono	Y	-	-	2.0	Y	-	-
7.		Pentax K-70	Y	stereo / mono	Y	-	mini	2.0	Y	-	-
8.		Pentax K-3 II	Y	mono / mono	Y	Y	mini	3.0	-	-	-
9.		Pentax K-50	Y	mono / mono	-	-	micro	2.0	-	-	-
10.		Pentax K-500	Y	mono / mono	-	-	-	2.0	-	-	-
11.		Pentax K-3	Y	mono / mono	Y	Y	mini	3.0	-	-	-
12.		Sony A68	Y	stereo / mono	Y	-	micro	2.0	-	-	-
13.		Sony A58	Y	stereo / mono	Y	-	mini	2.0	-	-	-

It is notable that the K-S2 offers wifi support, which can be a very convenient means to transfer image data to an off-camera location. In contrast, the K-S1 does not provide wifi capability.

Both the K-S1 and the K-S2 have been discontinued, but can regularly be found used on ebay. The K-S1 was replaced by the Pentax K-S2, while the K-S2 does not have a direct successor. Further information on the features and operation of the K-S1 and K-S2 can be found, respectively, in the Pentax K-S1 Manual (free pdf) or the online Pentax K-S2 Manual.

Review summary

So how do things add up? Is there a clear favorite between the Pentax K-S1 and the Pentax K-S2? Which camera is better? Below is a summary of the relative strengths of each of the two contestants.

Advantages of the Pentax K-S1:

• Less heavy: Is lighter (by 120g or 18 percent) and hence easier to carry around.
• More heavily discounted: Has been on the market for longer (launched in August 2014).

Arguments in favor of the Pentax K-S2:

• Better sound: Can connect to an external microphone for higher quality sound recording.
• 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.
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
• 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: Was introduced somewhat (5 months) more recently.

If the number of relative strengths (bullet points above) is taken as a guide, the K-S2 is the clear winner of the contest (8 : 2 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 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 Pentax K-S1 and the Pentax K-S2 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 says little about, for example, the shooting experience and imaging performance of the K-S1 and the K-S2 in practical situations. 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 hands-on reviews by experts 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.		Pentax K-S1	4/5	..	..	..	4.5/5	4/5	Aug 2014	749	ebay.com
2.		Pentax K-S2	4.5/5	..	..	..	5/5	4.5/5	Feb 2015	749	ebay.com
3.		Canon 750D	5/5	..	..	75/100	4.5/5	4.5/5	Feb 2015	749	ebay.com
4.		Canon 760D	5/5	+	..	77/100	4.5/5	4.5/5	Feb 2015	649	ebay.com
5.		Nikon D5300	4/5	+ +	..	79/100	4.5/5	4.5/5	Oct 2013	799	ebay.com
6.		Pentax KP	4/5	..	3/5	82/100	5/5	4.5/5	Jan 2017	1,099	ebay.com
7.		Pentax K-70	4.5/5	..	4/5	79/100	4.5/5	4.5/5	Jun 2016	649	ebay.com
8.		Pentax K-3 II	4.5/5	..	..	..	5/5	5/5	Apr 2015	1,099	ebay.com
9.		Pentax K-50	5/5	..	..	..	5/5	4.5/5	Jun 2013	599	ebay.com
10.		Pentax K-500	..	..	..	..	4.5/5	4.5/5	Jun 2013	549	ebay.com
11.		Pentax K-3	4/5	..	..	83/100	5/5	5/5	Oct 2013	1,299	ebay.com
12.		Sony A68	3/5	..	..	..	4/5	4/5	Nov 2015	699	ebay.com
13.		Sony A58	3/5	..	..	..	4.5/5	4.5/5	Feb 2013	599	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The review scores listed above should be treated with care, though. The ratings are only valid when referring to cameras in the same category and of the same age. Thus, a score needs to be put into the context of the launch date and the launch price of the camera, and rating-comparisons among cameras that span long time periods or concern very differently equipped models make little sense. Also, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.

Check K-S1 offers at
ebay.com
Check K-S2 offers at
ebay.com

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.

~

Check K-S1 offers at
ebay.com
Check K-S2 offers at
ebay.com

Did you notice an error on this page? If so, please get in touch, so that we can correct the information.