Pentax K-500 vs Sony A7S

The Pentax K-500 and the Sony Alpha A7S are two digital cameras that were revealed to the public, respectively, in June 2013 and April 2014. The K-500 is a DSLR, while the A7S is a mirrorless interchangeable lens camera. The cameras are based on an APS-C (K-500) and a full frame (A7S) sensor. The Pentax has a resolution of 16.1 megapixels, whereas the Sony provides 12 MP.

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

Headline Specifications

Pentax K-500		Sony A7S
Digital single lens reflex		Mirrorless system camera
Pentax K mount lenses		Sony E mount lenses
16.1 MP – APS-C sensor		12 MP – Full Frame sensor
1080/30p Video		1080/60p Video
ISO 100-51,200		ISO 100-102,400 (50 - 409,600)
Optical viewfinder		Electronic viewfinder (2400k dots)
3.0" LCD – 921k dots		3.0" LCD – 921k dots
Fixed screen (not touch-sensitive)		Tilting screen (no touchscreen)
6 shutter flaps per second		5 shutter flaps per second
In-body stabilization		Lens stabilization only
not weather sealed		Weathersealed body
710 shots per battery charge		380 shots per battery charge
130 x 97 x 71 mm, 646 g		127 x 94 x 48 mm, 489 g

Check K-500 offers at
ebay.com
Check A7S offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Pentax K-500 and the Sony Alpha A7S? 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 Pentax K-500 and the Sony A7S are illustrated in the side-by-side display below. 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 width, height and depth 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 is notably smaller (5 percent) than the Pentax K-500. Moreover, the A7S is markedly lighter (24 percent) than the K-500. It is noteworthy in this context that the A7S is splash and dust-proof, while the K-500 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 power pack in the A7S 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. 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.		Pentax K-500	130 mm	97 mm	71 mm	646 g	710	n	Jun 2013	549	ebay.com
2.		Sony A7S	127 mm	94 mm	48 mm	489 g	380	Y	Apr 2014	2,499	ebay.com
3.		Olympus E-M10 II	120 mm	83 mm	47 mm	390 g	320	n	Aug 2015	649	ebay.com
4.		Olympus E-M10	119 mm	82 mm	46 mm	396 g	320	n	Jan 2014	699	ebay.com
5.		Olympus E-PL7	115 mm	67 mm	38 mm	357 g	350	n	Aug 2014	599	ebay.com
6.		Olympus E-PL5	111 mm	64 mm	38 mm	325 g	360	n	Sep 2012	599	ebay.com
7.		Olympus E-PM2	110 mm	64 mm	34 mm	269 g	360	n	Sep 2012	499	ebay.com
8.		Pentax K-S1	121 mm	93 mm	70 mm	558 g	410	n	Aug 2014	749	ebay.com
9.		Pentax K-50	130 mm	97 mm	71 mm	650 g	410	Y	Jun 2013	599	ebay.com
10.		Pentax K-30	130 mm	97 mm	71 mm	650 g	410	Y	May 2012	849	ebay.com
11.		Pentax K-5 II	131 mm	97 mm	73 mm	760 g	740	Y	Sep 2012	1,099	ebay.com
12.		Pentax K-5	131 mm	97 mm	73 mm	760 g	740	Y	Sep 2010	1,099	ebay.com
13.		Sony ZV-E1	121 mm	72 mm	54 mm	483 g	570	Y	Mar 2023	2,199	amazon.com
14.		Sony A7S II	127 mm	96 mm	60 mm	627 g	370	Y	Sep 2015	2,999	ebay.com
15.		Sony A7	127 mm	94 mm	48 mm	474 g	340	Y	Oct 2013	1,699	ebay.com
16.		Sony A7R	127 mm	94 mm	48 mm	465 g	340	Y	Oct 2013	2,299	ebay.com
17.		Sony RX1R	113 mm	65 mm	70 mm	482 g	270	n	Jun 2013	2,799	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 K-500 was launched at a markedly lower price (by 78 percent) than the A7S, 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.

Sensor comparison

The size of the imaging sensor is a crucial determinant of image quality. All other things equal, a large sensor will have larger individual pixel-units that offer better low-light sensitivity, wider dynamic range, and 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.

Of the two cameras under consideration, the Pentax K-500 features an APS-C sensor and the Sony A7S a full frame sensor. The sensor area in the A7S is 133 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.5 and 1.0. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

Despite having a smaller sensor, the Pentax K-500 offers a higher resolution of 16.1 megapixels, compared with 12 MP of the Sony A7S. 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 4.77μm versus 8.45μm for the A7S). Moreover, it should be noted that the A7S is a somewhat more recent model (by 9 months) than the K-500, and its sensor might have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixel-units.

The resolution advantage of the Pentax K-500 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the K-500 for good quality output (200 dots per inch) amounts to 24.6 x 16.3 inches or 62.6 x 41.5 cm, for very good quality (250 dpi) 19.7 x 13.1 inches or 50.1 x 33.2 cm, and for excellent quality (300 dpi) 16.4 x 10.9 inches or 41.7 x 27.6 cm. The corresponding values for the Sony A7S are 21.2 x 14.2 inches or 53.8 x 36 cm for good quality, 17 x 11.3 inches or 43.1 x 28.8 cm for very good quality, and 14.1 x 9.4 inches or 35.9 x 24 cm for excellent quality prints.

The Pentax K-500 has a native sensitivity range from ISO 100 to ISO 51200. The corresponding ISO settings for the Sony Alpha A7S 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 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 A7S has a markedly higher DXO score than the K-500 (overall score 8 points higher), which will translate into better image quality. The advantage is based on 0.2 bits higher color depth, 0.1 EV in additional dynamic range, and 1.8 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 K-500	APS-C	16.1	4928	3264	1080/30p	23.7	13.1	1087	79
2.		Sony A7S	Full Frame	12.0	4240	2832	1080/60p	23.9	13.2	3702	87
3.		Olympus E-M10 II	Four Thirds	15.9	4608	3456	1080/60p	23.1	12.5	842	73
4.		Olympus E-M10	Four Thirds	15.9	4608	3456	1080/30p	22.8	12.3	884	72
5.		Olympus E-PL7	Four Thirds	15.9	4608	3456	1080/30p	22.7	12.4	873	72
6.		Olympus E-PL5	Four Thirds	15.9	4608	3456	1080/30p	22.8	12.3	889	72
7.		Olympus E-PM2	Four Thirds	15.9	4608	3456	1080/30p	22.7	12.2	932	72
8.		Pentax K-S1	APS-C	20.0	5472	3648	1080/30p	23.5	13.0	1061	78
9.		Pentax K-50	APS-C	16.1	4928	3264	1080/30p	23.7	13.0	1120	79
10.		Pentax K-30	APS-C	16.1	4928	3264	1080/30p	23.7	13.0	1129	79
11.		Pentax K-5 II	APS-C	16.1	4928	3264	1080/25p	23.8	14.1	1235	82
12.		Pentax K-5	APS-C	16.1	4928	3264	1080/25p	23.7	14.1	1162	82
13.		Sony ZV-E1	Full Frame	12.0	4240	2832	4K/60p	25.4	14.6	3181	96
14.		Sony A7S II	Full Frame	12.0	4240	2832	4K/30p	23.6	13.3	2993	85
15.		Sony A7	Full Frame	24.0	6000	4000	1080/60p	24.8	14.2	2248	90
16.		Sony A7R	Full Frame	36.2	7360	4912	1080/60p	25.6	14.1	2746	95
17.		Sony RX1R	Full Frame	24.0	6000	4000	1080/60p	25.0	13.6	2537	91
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 are equipped with sensors that have a sufficiently high read-out speed for moving images, but the A7S provides a faster frame rate than the K-500. It can shoot movie footage at 1080/60p, while the Pentax is limited to 1080/30p.

Feature comparison

Beyond body and sensor, cameras can and do differ across a range of features. For example, the A7S has an electronic viewfinder (2400k dots), while the K-500 has an optical one. Both systems have their advantages, with the electronic viewfinder making it possible to project supplementary shooting information into the framing view, whereas the optical viewfinder offers lag-free viewing and a very clear framing image. The viewfinders of both cameras offer the same field of view (100%), but the viewfinder of the A7S has a higher magnification than the one of the K-500 (0.71x vs 0.61x), 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 Pentax K-500 and Sony A7S 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-500	optical	n	3.0 / 921	fixed	n	1/6000s	6.0/s	Y	Y
2.		Sony A7S	2400	n	3.0 / 921	tilting	n	1/8000s	5.0/s	n	n
3.		Olympus E-M10 II	2360	n	3.0 / 1040	tilting	Y	1/4000s	8.0/s	Y	Y
4.		Olympus E-M10	1440	n	3.0 / 1037	tilting	Y	1/4000s	8.0/s	Y	Y
5.		Olympus E-PL7	optional	n	3.0 / 1037	tilting	Y	1/4000s	8.0/s	n	Y
6.		Olympus E-PL5	optional	n	3.0 / 460	tilting	Y	1/4000s	8.0/s	n	Y
7.		Olympus E-PM2	optional	n	3.0 / 460	fixed	Y	1/4000s	8.0/s	n	Y
8.		Pentax K-S1	optical	n	3.0 / 921	fixed	n	1/6000s	5.4/s	Y	Y
9.		Pentax K-50	optical	n	3.0 / 921	fixed	n	1/6000s	6.0/s	Y	Y
10.		Pentax K-30	optical	n	3.0 / 921	fixed	n	1/6000s	6.0/s	Y	Y
11.		Pentax K-5 II	optical	Y	3.0 / 921	fixed	n	1/8000s	7.0/s	Y	Y
12.		Pentax K-5	optical	Y	3.0 / 921	fixed	n	1/8000s	7.0/s	Y	Y
13.		Sony ZV-E1	none	n	3.0 / 1037	swivel	Y	1/8000s	10.0/s	n	Y
14.		Sony A7S II	2400	n	3.0 / 1229	tilting	n	1/8000s	5.0/s	n	Y
15.		Sony A7	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	n
16.		Sony A7R	2400	n	3.0 / 1230	tilting	n	1/8000s	4.0/s	n	n
17.		Sony RX1R	optional	n	3.0 / 1229	fixed	n	1/4000s	5.0/s	Y	n
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 K-500 has one, while the A7S does not. While the built-in flash of the K-500 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 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 Pentax K-500 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 K-500 writes its imaging data to SDXC cards, while the A7S uses SDXC or Memory Stick PRO Duo cards. The A7S supports UHS-I cards (Ultra High Speed data transfer of up to 104 MB/s), while the K-500 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 K-500 and Sony Alpha A7S 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-500	Y	mono / mono	-	-	-	2.0	-	-	-
2.		Sony A7S	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
3.		Olympus E-M10 II	Y	stereo / mono	-	-	micro	2.0	Y	-	-
4.		Olympus E-M10	Y	stereo / mono	-	-	micro	2.0	Y	-	-
5.		Olympus E-PL7	Y	stereo / mono	-	-	micro	2.0	Y	-	-
6.		Olympus E-PL5	Y	stereo / mono	-	-	mini	2.0	-	-	-
7.		Olympus E-PM2	Y	stereo / mono	-	-	mini	2.0	-	-	-
8.		Pentax K-S1	Y	stereo / mono	-	-	micro	2.0	-	-	-
9.		Pentax K-50	Y	mono / mono	-	-	micro	2.0	-	-	-
10.		Pentax K-30	Y	mono / mono	-	-	-	2.0	-	-	-
11.		Pentax K-5 II	Y	stereo / mono	Y	-	mini	2.0	-	-	-
12.		Pentax K-5	Y	stereo / mono	Y	-	mini	2.0	-	-	-
13.		Sony ZV-E1	Y	stereo / mono	Y	Y	micro	3.2	Y	-	Y
14.		Sony A7S II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
15.		Sony A7	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
16.		Sony A7R	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
17.		Sony RX1R	Y	stereo / mono	Y	-	mini	2.0	-	-	-

It is notable that the A7S offers wifi support, which can be a very convenient means to transfer image data to an off-camera location. In contrast, the K-500 does not provide wifi capability.

Both the K-500 and the A7S have been discontinued, but can regularly be found used on ebay. The A7S was replaced by the Sony A7S II, while the K-500 does not have a direct successor. Further information on the features and operation of the K-500 and A7S can be found, respectively, in the Pentax K-500 Manual (free pdf) or the online Sony A7S Manual.

Review summary

So what conclusions can be drawn? Is the Pentax K-500 better than the Sony A7S or vice versa? A synthesis of the relative strong points of each of the models is listed below.

Advantages of the Pentax K-500:

• More detail: Offers more megapixels (16.1 vs 12MP) with a 16% higher linear resolution.
• Brighter framing: Features an optical viewfinder for clear, lag-free composition.
• Faster burst: Shoots at higher frequency (6 vs 5 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 (710 versus 380) on a single battery charge.
• Sharper images: Has hand-shake reducing image stabilization built-in.
• Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
• More affordable: Was introduced into a lower priced category (78 percent cheaper at launch).
• More heavily discounted: Has been on the market for longer (launched in June 2013).

Arguments in favor of the Sony Alpha A7S:

• Better image quality: Scores markedly higher (8 points) in the DXO overall evaluation.
• Better low-light sensitivity: Can shoot in dim conditions (1.8 stops ISO advantage).
• Better video: Provides higher movie framerates (1080/60p versus 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.
• More framing info: Has an electronic viewfinder that displays shooting data.
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.71x vs 0.61x).
• More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/6000s) to freeze action.
• Less disturbing: Has an electronic shutter option for completely silent shooting.
• Less heavy: Has a lower weight (by 157g or 24 percent) and is thus easier to take along.
• Easier travel charging: Can be conveniently charged via its USB port.
• Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
• More legacy lens friendly: Can use many non-native lenses via adapters.
• 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: Was introduced somewhat (9 months) more recently.

If the count of individual advantages (bullet points above) is taken as a guide, the A7S is the clear winner of the contest (18 : 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 Pentax K-500 and the Sony A7S place the cameras among the top in their class? Find out in the latest Best DSLR 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 the spec-sheets of cameras can offer a general idea of their imaging potential, it remains incomplete and does no justice, for example, to the way the K-500 or the A7S 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.		Pentax K-500	..	..	..	..	4.5/5	4.5/5	Jun 2013	549	ebay.com
2.		Sony A7S	4/5	..	..	86/100	4.5/5	5/5	Apr 2014	2,499	ebay.com
3.		Olympus E-M10 II	4.5/5	+ +	..	80/100	5/5	5/5	Aug 2015	649	ebay.com
4.		Olympus E-M10	4/5	..	..	80/100	5/5	5/5	Jan 2014	699	ebay.com
5.		Olympus E-PL7	4/5	+	..	..	5/5	4/5	Aug 2014	599	ebay.com
6.		Olympus E-PL5	3/5	+ +	..	..	4.5/5	4.5/5	Sep 2012	599	ebay.com
7.		Olympus E-PM2	3/5	..	..	77/100	5/5	4.5/5	Sep 2012	499	ebay.com
8.		Pentax K-S1	4/5	..	..	..	4.5/5	4/5	Aug 2014	749	ebay.com
9.		Pentax K-50	5/5	..	..	..	5/5	4.5/5	Jun 2013	599	ebay.com
10.		Pentax K-30	4/5	..	..	78/100	4.5/5	4.5/5	May 2012	849	ebay.com
11.		Pentax K-5 II	5/5	..	..	80/100	5/5	4.5/5	Sep 2012	1,099	ebay.com
12.		Pentax K-5	4/5	..	..	83/100	5/5	4.5/5	Sep 2010	1,099	ebay.com
13.		Sony ZV-E1	..	+	4/5	..	..	4.5/5	Mar 2023	2,199	amazon.com
14.		Sony A7S II	5/5	+	..	..	4.5/5	5/5	Sep 2015	2,999	ebay.com
15.		Sony A7	5/5	+ +	..	80/100	5/5	5/5	Oct 2013	1,699	ebay.com
16.		Sony A7R	5/5	+ +	..	82/100	4.5/5	5/5	Oct 2013	2,299	ebay.com
17.		Sony RX1R	5/5	..	..	..	4/5	4.5/5	Jun 2013	2,799	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The above review scores should be interpreted 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 comparing ratings of very distinct cameras or ones that are far apart in terms of their release date have little meaning. 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

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