Pentax MX-1 vs Sony A7S II

The Pentax MX-1 and the Sony Alpha 7S II are two digital cameras that were officially introduced, respectively, in January 2013 and September 2015. The MX-1 is a fixed lens compact, while the A7S II is a mirrorless interchangeable lens camera. The cameras are based on a 1/1.7-inch (MX-1) and a full frame (A7S II) sensor. Both cameras offer a resolution of 12 megapixels.

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

Headline Specifications

Pentax MX-1		Sony A7S II
Fixed lens compact camera		Mirrorless system camera
28-112mm f/1.8-2.5		Sony E mount lenses
12 MP – 1/1.7" sensor		12 MP – Full Frame sensor
1080/30p Video		4K/30p Video
ISO 100-12,800		ISO 100-102,400 (50 - 409,600)
No viewfinder, LCD framing		Electronic viewfinder (2400k dots)
3.0" LCD – 920k dots		3.0" LCD – 1229k dots
Tilting screen (no touchscreen)		Tilting screen (no touchscreen)
1 shutter flaps per second		5 shutter flaps per second
In-body stabilization		In-body stabilization
not weather sealed		Weathersealed body
290 shots per battery charge		370 shots per battery charge
122 x 61 x 51 mm, 391 g		127 x 96 x 60 mm, 627 g

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Going beyond this snapshot of core features and characteristics, what are the differences between the Pentax MX-1 and the Sony Alpha 7S II? 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 Pentax MX-1 and the Sony A7S II. 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.

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Sony A7S II is considerably larger (64 percent) than the Pentax MX-1. It is noteworthy in this context that the A7S II is splash and dust-proof, while the MX-1 does not feature any corresponding weather-sealing.

The above size and weight comparisons are to some extent incomplete and possibly misleading, as the MX-1 has a lens built in, whereas the A7S II is an interchangeable lens camera that requires a separate lens. Attaching the latter will add extra weight and bulk to the setup. You can compare the optics available for the A7S II and their specifications in the Sony FE Lens Catalog.

The power pack in the A7S II can be charged via the USB port, which can be very convenient when travelling.

The table below summarizes the key physical specs of the two cameras alongside a broader set of comparators. 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.

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 MX-1	122 mm	61 mm	51 mm	391 g	290	n	Jan 2013	499	ebay.com
2.		Sony A7S II	127 mm	96 mm	60 mm	627 g	370	Y	Sep 2015	2,999	ebay.com
3.		Canon G15	107 mm	76 mm	40 mm	352 g	350	n	Sep 2012	499	ebay.com
4.		Canon G16	109 mm	76 mm	40 mm	356 g	360	n	Aug 2013	549	ebay.com
5.		Canon S120	100 mm	59 mm	29 mm	217 g	230	n	Aug 2013	449	ebay.com
6.		Fujifilm X10	117 mm	70 mm	57 mm	350 g	270	n	Sep 2011	599	ebay.com
7.		Fujifilm X20	117 mm	70 mm	57 mm	353 g	270	n	Jan 2013	599	ebay.com
8.		Fujifilm X30	119 mm	72 mm	60 mm	423 g	470	n	Aug 2014	599	ebay.com
9.		Nikon P7800	119 mm	78 mm	50 mm	399 g	350	n	Sep 2013	549	ebay.com
10.		Olympus Stylus 1	116 mm	87 mm	57 mm	402 g	410	n	Oct 2013	699	ebay.com
11.		Olympus XZ-2	113 mm	65 mm	48 mm	346 g	340	n	Sep 2012	599	ebay.com
12.		Panasonic LF1	103 mm	62 mm	28 mm	192 g	250	n	Apr 2013	499	ebay.com
13.		Sony A7 IV	131 mm	96 mm	80 mm	659 g	580	Y	Oct 2021	2,499	amazon.com
14.		Sony A7R II	127 mm	96 mm	60 mm	625 g	290	Y	Jun 2015	3,199	ebay.com
15.		Sony A7R IV	129 mm	96 mm	78 mm	665 g	670	Y	Jul 2019	3,499	ebay.com
16.		Sony A7S	127 mm	94 mm	48 mm	489 g	380	Y	Apr 2014	2,499	ebay.com
17.		Sony A7S III	127 mm	97 mm	81 mm	699 g	600	Y	Jul 2020	3,499	amazon.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 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 MX-1 was launched at a lower price than the A7S II, despite having a lens built in. 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.

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. 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 are more costly to manufacture and tend to lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the Pentax MX-1 features a 1/1.7-inch sensor and the Sony A7S II a full frame sensor. The sensor area in the A7S II is 1870 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 4.5 and 1.0. The sensor in the MX-1 has a native 4:3 aspect ratio, while the one in the A7S II offers a 3:2 aspect.

Even though the A7S II has a larger sensor, both cameras offer the same resolution of 12 megapixels. This implies that the A7S II has a lower pixel density and larger individual pixels (with a pixel pitch of 8.40μm versus 1.89μm for the MX-1), which gives it a potential advantage in terms of light gathering capacity. In addition, the A7S II is much more recent (by 2 years and 8 months) than the MX-1, and its sensor will have benefitted from technological advances during this time.

The Pentax MX-1 has a native sensitivity range from ISO 100 to ISO 12800. The corresponding ISO settings for the Sony Alpha 7S II are ISO 100 to ISO 102400, with the possibility to increase the ISO range to 50-409600.

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 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 A7S II offers substantially better image quality than the MX-1 (overall score 36 points higher). The advantage is based on 3.2 bits higher color depth, 2 EV in additional dynamic range, and 3.8 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.

Sensor Characteristics

		Camera Model	Sensor Class	Resolution (MP)	Horiz. Pixels	Vert. Pixels	Video Format	DXO Portrait	DXO Landscape	DXO Sports	DXO Overall
1.		Pentax MX-1	1/1.7	12.0	4000	3000	1080/30p	20.4	11.3	208	49
2.		Sony A7S II	Full Frame	12.0	4240	2832	4K/30p	23.6	13.3	2993	85
3.		Canon G15	1/1.7	12.0	4000	3000	1080/24p	19.9	11.5	165	46
4.		Canon G16	1/1.7	12.0	4000	3000	1080/60p	21.0	11.7	230	54
5.		Canon S120	1/1.7	12.0	4000	3000	1080/60p	21.3	11.9	246	56
6.		Fujifilm X10	2/3	12.0	4000	3000	1080/30p	20.5	11.3	245	50
7.		Fujifilm X20	2/3	12.0	4000	3000	1080/60p	20.1	10.9	-462	46
8.		Fujifilm X30	2/3	12.0	4000	3000	1080/60p	20.4	11.2	-312	49
9.		Nikon P7800	1/1.7	12.0	4000	3000	1080/30p	21.2	11.7	200	54
10.		Olympus Stylus 1	1/1.7	11.8	3968	2976	1080/30p	20.7	11.6	179	51
11.		Olympus XZ-2	1/1.7	11.8	3968	2976	1080/30p	20.4	11.3	216	49
12.		Panasonic LF1	1/1.7	12.0	4000	3000	1080/60i	20.8	11.6	211	52
13.		Sony A7 IV	Full Frame	32.7	7008	4672	4K/60p	25.4	14.7	3379	97
14.		Sony A7R II	Full Frame	42.2	7952	5304	4K/30p	26.0	13.9	3434	98
15.		Sony A7R IV	Full Frame	60.2	9504	6336	4K/30p	26.0	14.8	3344	99
16.		Sony A7S	Full Frame	12.0	4240	2832	1080/60p	23.9	13.2	3702	87
17.		Sony A7S III	Full Frame	12.0	4240	2832	4K/120p	23.7	13.9	2520	86
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. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, but the A7S II provides a better video resolution than the MX-1. It can shoot movie footage at 4K/30p, 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. For example, the A7S II has an electronic viewfinder (2400k dots), which can be very helpful when shooting in bright sunlight. In contrast, the MX-1 relies on live view and the rear LCD for framing. The adjacent table lists some of the other core features of the Pentax MX-1 and Sony A7S II 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 MX-1	none	n	3.0 / 920	tilting	n	1/8000s	1.0/s	Y	Y
2.		Sony A7S II	2400	n	3.0 / 1229	tilting	n	1/8000s	5.0/s	n	Y
3.		Canon G15	optical	n	3.0 / 922	fixed	n	1/4000s	2.1/s	Y	Y
4.		Canon G16	optical	n	3.0 / 922	fixed	n	1/4000s	2.2/s	Y	Y
5.		Canon S120	none	n	3.0 / 922	fixed	Y	1/2000s	12.1/s	Y	Y
6.		Fujifilm X10	optical	n	2.8 / 460	fixed	n	1/4000s	10.0/s	Y	Y
7.		Fujifilm X20	optical	n	2.8 / 460	fixed	n	1/4000s	12.0/s	Y	Y
8.		Fujifilm X30	2360	n	3.0 / 920	tilting	n	1/4000s	12.0/s	Y	Y
9.		Nikon P7800	921	n	3.0 / 921	swivel	n	1/4000s	8.0/s	Y	Y
10.		Olympus Stylus 1	1440	n	3.0 / 1040	tilting	Y	1/2000s	7.0/s	Y	Y
11.		Olympus XZ-2	optional	n	3.0 / 920	tilting	Y	1/2000s	5.0/s	Y	Y
12.		Panasonic LF1	200	n	3.0 / 920	fixed	n	1/4000s	10.0/s	Y	Y
13.		Sony A7 IV	3686	n	3.0 / 1037	swivel	Y	1/8000s	10.0/s	n	Y
14.		Sony A7R II	2400	n	3.0 / 1229	tilting	n	1/8000s	5.0/s	n	Y
15.		Sony A7R IV	5760	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
16.		Sony A7S	2400	n	3.0 / 921	tilting	n	1/8000s	5.0/s	n	n
17.		Sony A7S III	9440	n	3.0 / 1440	swivel	Y	1/8000s	10.0/s	n	Y
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One difference between the cameras concerns the presence of an on-board flash. The MX-1 has one, while the A7S II does not. While the built-in flash of the MX-1 is not very powerful, it can at times be useful as a fill-in light.

The reported shutter speed information refers to the use of the mechanical shutter. Yet, some cameras only have an electronic shutter, while others have an electronic shutter in addition to a mechanical one. In fact, the A7S II is one of those camera that have an additional electronic shutter, which makes completely silent shooting possible. However, this mode is less suitable for photographing moving objects (risk of rolling shutter) or shooting under artificial light sources (risk of flickering).

The MX-1 writes its imaging data to SDXC cards, while the A7S II uses SDXC or Memory Stick PRO Duo cards. The A7S II supports UHS-I cards (Ultra High Speed data transfer of up to 104 MB/s), while the MX-1 cannot take advantage of Ultra High Speed SD cards.

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 MX-1 and Sony Alpha 7S II 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 MX-1	-	stereo / mono	-	-	mini	2.0	-	-	-
2.		Sony A7S II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
3.		Canon G15	Y	stereo / mono	-	-	mini	2.0	-	-	-
4.		Canon G16	Y	stereo / mono	-	-	mini	2.0	Y	-	-
5.		Canon S120	-	stereo / mono	-	-	mini	2.0	Y	-	-
6.		Fujifilm X10	Y	stereo / mono	-	-	mini	2.0	-	-	-
7.		Fujifilm X20	Y	stereo / mono	-	-	micro	2.0	-	-	-
8.		Fujifilm X30	Y	stereo / mono	-	-	micro	2.0	Y	-	-
9.		Nikon P7800	Y	stereo / mono	Y	-	mini	2.0	-	-	-
10.		Olympus Stylus 1	Y	stereo / mono	-	-	micro	2.0	Y	-	-
11.		Olympus XZ-2	Y	stereo / mono	-	-	mini	2.0	-	-	-
12.		Panasonic LF1	-	stereo / mono	-	-	mini	2.0	Y	Y	-
13.		Sony A7 IV	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
14.		Sony A7R II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
15.		Sony A7R IV	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
16.		Sony A7S	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
17.		Sony A7S III	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y

It is notable that the A7S II offers wifi support, which can be a very convenient means to transfer image data to an off-camera location. In contrast, the MX-1 does not provide wifi capability.

Both the MX-1 and the A7S II have been discontinued, but can regularly be found used on ebay. The A7S II was replaced by the Sony A7S III, while the MX-1 does not have a direct successor. Further information on the features and operation of the MX-1 and A7S II can be found, respectively, in the Pentax MX-1 Manual (free pdf) or the online Sony A7S II Manual.

Review summary

So what conclusions can be drawn? Is there a clear favorite between the Pentax MX-1 and the Sony A7S II? Which camera is better? Below is a summary of the relative strengths of each of the two contestants.

Advantages of the Pentax MX-1:

• Ready to shoot: Has a lens built-in, whereas the A7S II requires a separate lens.
• More compact: Is smaller (122x61mm vs 127x96mm) and thus needs less room in the bag.
• Less heavy: Is lighter even though it comes with a built-in lens (unlike the A7S II).
• Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
• More affordable: Was introduced at a lower price, despite coming with a built-in lens.
• More heavily discounted: Has been available for much longer (launched in January 2013).

Arguments in favor of the Sony Alpha 7S II:

• Better image quality: Scores substantially higher (36 points) in the DXO overall evaluation.
• Richer colors: Generates noticeably more natural colors (3.2 bits more color depth).
• More dynamic range: Captures a broader range of light and dark details (2 EV of extra DR).
• Better low-light sensitivity: Can shoot in dim conditions (3.8 stops ISO advantage).
• Better video: Provides higher definition movie capture (4K/30p vs 1080/30p).
• Better sound: Can connect to an external microphone for higher quality sound recording.
• Better sound control: Has a headphone port that enables audio monitoring while recording.
• Easier framing: Has an electronic viewfinder for image composition and settings control.
• More detailed LCD: Has a higher resolution rear screen (1229k vs 920k dots).
• Faster burst: Shoots at higher frequency (5 vs 1 flaps/sec) to capture the decisive moment.
• Less disturbing: Has an electronic shutter option for completely silent shooting.
• More flexible: Takes interchangeable lenses and can thus be used with specialty optics.
• Longer lasting: Gets more shots (370 versus 290) out of a single battery charge.
• Easier travel charging: Can be conveniently charged via its USB port.
• Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
• Better lighting: Features a hotshoe and can thus hold and trigger an external flash gun.
• 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.
• Faster buffer clearing: Has an SD card interface that supports the UHS-I standard.
• More modern: Reflects 2 years and 8 months of technical progress since the MX-1 launch.

If the number of relative strengths (bullet points above) is taken as a guide, the A7S II is the clear winner of the contest (20 : 6 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 MX-1 and the Sony A7S II place the cameras among the top in their class? Find out in the latest Best Travel-Zoom Camera and Best Mirrorless Interchangeable Lens Camera listings 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 MX-1 or the A7S II. User reviews that are available, for instance, at amazon can sometimes shed light on these issues, but such feedback is all too often partial, inconsistent, and inaccurate.

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.		Pentax MX-1	3/5	..	..	74/100	4/5	4/5	Jan 2013	499	ebay.com
2.		Sony A7S II	5/5	+	..	..	4.5/5	5/5	Sep 2015	2,999	ebay.com
3.		Canon G15	4/5	+	..	76/100	4.5/5	4.5/5	Sep 2012	499	ebay.com
4.		Canon G16	4/5	+	..	..	4.5/5	4.5/5	Aug 2013	549	ebay.com
5.		Canon S120	..	+ +	..	..	4.5/5	4.5/5	Aug 2013	449	ebay.com
6.		Fujifilm X10	..	..	..	76/100	4/5	4.5/5	Sep 2011	599	ebay.com
7.		Fujifilm X20	4/5	+ +	..	77/100	4.5/5	5/5	Jan 2013	599	ebay.com
8.		Fujifilm X30	4/5	..	..	76/100	4.5/5	4.5/5	Aug 2014	599	ebay.com
9.		Nikon P7800	3/5	..	..	..	4/5	4.5/5	Sep 2013	549	ebay.com
10.		Olympus Stylus 1	..	+ +	..	..	4.5/5	4.5/5	Oct 2013	699	ebay.com
11.		Olympus XZ-2	4/5	+	..	..	4.5/5	4.5/5	Sep 2012	599	ebay.com
12.		Panasonic LF1	3/5	+	..	..	4/5	4.5/5	Apr 2013	499	ebay.com
13.		Sony A7 IV	5/5	+ +	4.5/5	89/100	4.5/5	4.5/5	Oct 2021	2,499	amazon.com
14.		Sony A7R II	5/5	+ +	5/5	90/100	5/5	5/5	Jun 2015	3,199	ebay.com
15.		Sony A7R IV	5/5	+	4.5/5	91/100	4.5/5	5/5	Jul 2019	3,499	ebay.com
16.		Sony A7S	4/5	..	..	86/100	4.5/5	5/5	Apr 2014	2,499	ebay.com
17.		Sony A7S III	4.5/5	+ +	5/5	91/100	4.5/5	5/5	Jul 2020	3,499	amazon.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The above review scores should be interpreted 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, please note that some of the review sites have changed their methodology and reporting over time.

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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 your choice using the following search menu. As an alternative, you can also directly jump to any one of the listed comparisons that were previously generated by the CAM-parator tool.

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