Pentax K-5 II vs Sony A99

The Pentax K-5 II and the Sony Alpha SLT-A99 are two digital cameras that were officially introduced in September 2012. Both are DSLR (Digital Single Lens Reflex) cameras that are based on an APS-C (K-5 II) and a full frame (A99) sensor. The Pentax has a resolution of 16.1 megapixels, whereas the Sony provides 24 MP.

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

Headline Specifications

Pentax K-5 II		Sony A99
Digital single lens reflex		Digital single lens reflex
Pentax K mount lenses		Sony A mount lenses
16.1 MP – APS-C sensor		24 MP – Full Frame sensor
1080/25p Video		1080/60p Video
ISO 100-12,800 (80 - 51,200)		ISO 100-25,600
Optical viewfinder		Electronic viewfinder (2359k dots)
3.0" LCD – 921k dots		3.0" LCD – 1229k dots
Fixed screen (not touch-sensitive)		Fully flexible screen (no touchscreen)
7 shutter flaps per second		6 shutter flaps per second
In-body stabilization		In-body stabilization
Weathersealed body		Weathersealed body
740 shots per battery charge		500 shots per battery charge
131 x 97 x 73 mm, 760 g		147 x 111 x 78 mm, 812 g

Check K-5 II offers at
ebay.com
Check A99 offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Pentax K-5 II and the Sony Alpha SLT-A99? 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-5 II and the Sony A99 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.

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Sony A99 is notably larger (28 percent) than the Pentax K-5 II. Moreover, the A99 is markedly heavier (7 percent) than the K-5 II. In this context, it is worth noting that both cameras are splash and dust-proof and can, hence, be used in inclement weather conditions or harsh environments.

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 K-5 II gets 740 shots out of its Pentax D-LI90 battery, while the A99 can take 500 images on a single charge of its Sony NP-FM500H power pack.

The adjacent table lists the principal physical characteristics of the two cameras alongside a wider set of alternatives. 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	Street Price
1.		Pentax K-5 II	131 mm	97 mm	73 mm	760 g	740	Y	Sep 2012	US$ 1 099	ebay.com
2.		Sony A99	147 mm	111 mm	78 mm	812 g	500	Y	Sep 2012	US$ 2 799	ebay.com
3.		Nikon Df	144 mm	110 mm	67 mm	760 g	1400	Y	Nov 2013	US$ 2 749	ebay.com
4.		Olympus E-M5	122 mm	89 mm	43 mm	425 g	360	Y	Feb 2012	US$ 1 299	ebay.com
5.		Olympus E-M5 II	124 mm	85 mm	45 mm	469 g	310	Y	Feb 2015	US$ 1 099	ebay.com
6.		Pentax K-3	131 mm	100 mm	77 mm	800 g	560	Y	Oct 2013	US$ 1 299	ebay.com
7.		Pentax K-3 II	131 mm	100 mm	77 mm	800 g	720	Y	Apr 2015	US$ 1 099	ebay.com
8.		Pentax K-5	131 mm	97 mm	73 mm	760 g	740	Y	Sep 2010	US$ 1 099	ebay.com
9.		Pentax K-30	130 mm	97 mm	71 mm	650 g	410	Y	May 2012	US$ 849	ebay.com
10.		Pentax K-50	130 mm	97 mm	71 mm	650 g	410	Y	Jun 2013	US$ 599	ebay.com
11.		Pentax K-500	130 mm	97 mm	71 mm	646 g	710	n	Jun 2013	US$ 549	ebay.com
12.		Pentax KP	132 mm	101 mm	76 mm	703 g	390	Y	Jan 2017	US$ 1 099	ebay.com
13.		Sony A9	127 mm	96 mm	63 mm	673 g	650	Y	Apr 2017	US$ 4 499	ebay.com
14.		Sony A77	143 mm	104 mm	81 mm	732 g	470	Y	Aug 2011	US$ 1 399	ebay.com
15.		Sony A99 II	143 mm	104 mm	76 mm	849 g	490	Y	Sep 2016	US$ 3 199	ebay.com
16.		Sony A850	156 mm	117 mm	82 mm	895 g	880	Y	Aug 2009	US$ 1 999	ebay.com
17.		Sony A900	156 mm	117 mm	82 mm	895 g	880	Y	Sep 2008	US$ 2 999	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 K-5 II was launched at a markedly lower price (by 61 percent) than the A99, which puts it into a different 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 imaging sensor is at the core of digital cameras and its size is one of the main determining factors 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. 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.

Of the two cameras under consideration, the Pentax K-5 II features an APS-C sensor and the Sony A99 a full frame sensor. The sensor area in the A99 is 129 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.

With 24MP, the A99 offers a higher resolution than the K-5 II (16.1MP), but the A99 nevertheless has larger individual pixels (pixel pitch of 5.96μm versus 4.81μm for the K-5 II) due to its larger sensor. It is noteworthy in this context that the two cameras were released in close succession, so that their sensors are from the same technological generation.

The resolution advantage of the Sony A99 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A99 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-5 II are 24.6 x 16.3 inches or 62.6 x 41.5 cm for good quality, 19.7 x 13.1 inches or 50.1 x 33.2 cm for very good quality, and 16.4 x 10.9 inches or 41.7 x 27.6 cm for excellent quality prints.

The Pentax K-5 II has a native sensitivity range from ISO 100 to ISO 12800, which can be extended to ISO 80-51200. The corresponding ISO settings for the Sony Alpha SLT-A99 are ISO 100 to ISO 25600, with the possibility to increase the ISO range to 50-25600.

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 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 A99 has a markedly higher DXO score than the K-5 II (overall score 7 points higher), which will translate into better image quality. The advantage is based on 1.2 bits higher color depth, 0.1 EV of lower dynamic range, and 0.3 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.		Pentax K-5 II	APS-C	16.1	4928	3264	1080/25p	23.8	14.1	1235	82
2.		Sony A99	Full Frame	24.0	6000	4000	1080/60p	25.0	14.0	1555	89
3.		Nikon Df	Full Frame	16.2	4928	3280	none	24.6	13.1	3279	89
4.		Olympus E-M5	Four Thirds	15.9	4608	3456	1080/60i	22.8	12.3	826	71
5.		Olympus E-M5 II	Four Thirds	15.9	4608	3456	1080/60p	23.0	12.5	842	73
6.		Pentax K-3	APS-C	24.1	6016	4000	1080/60i	23.7	13.4	1216	80
7.		Pentax K-3 II	APS-C	24.1	6016	4000	1080/60i	23.6	13.6	1106	80
8.		Pentax K-5	APS-C	16.1	4928	3264	1080/25p	23.7	14.1	1162	82
9.		Pentax K-30	APS-C	16.1	4928	3264	1080/30p	23.7	13.0	1129	79
10.		Pentax K-50	APS-C	16.1	4928	3264	1080/30p	23.7	13.0	1120	79
11.		Pentax K-500	APS-C	16.1	4928	3264	1080/30p	23.7	13.1	1087	79
12.		Pentax KP	APS-C	24.1	6016	4000	1080/60i	23.9	13.2	1699	81
13.		Sony A9	Full Frame	24.0	6000	4000	4K/30p	24.9	13.3	3517	92
14.		Sony A77	APS-C	24.0	6000	4000	1080/60p	24.0	13.2	801	78
15.		Sony A99 II	Full Frame	42.2	7952	5304	4K/30p	25.4	13.4	2317	92
16.		Sony A850	Full Frame	24.4	6048	4032	none	23.8	12.2	1415	79
17.		Sony A900	Full Frame	24.4	6048	4032	none	23.7	12.3	1431	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. Both cameras under consideration are equipped with sensors that have a sufficiently high read-out speed for moving images, but the A99 provides a faster frame rate than the K-5 II. It can shoot movie footage at 1080/60p, while the Pentax is limited to 1080/25p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a range of features. For example, the A99 has an electronic viewfinder (2359k dots), while the K-5 II 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 A99 has a higher magnification than the one of the K-5 II (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 table below summarizes some of the other core capabilities of the Pentax K-5 II and Sony A99 in connection with corresponding information for a sample of similar cameras.

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-5 II	optical	Y	3.0 / 921	fixed	n	1/8000s	7.0/s	Y	Y
2.		Sony A99	2359	Y	3.0 / 1229	full-flex	n	1/8000s	6.0/s	n	Y
3.		Nikon Df	optical	Y	3.2 / 921	fixed	n	1/4000s	5.5/s	n	n
4.		Olympus E-M5	1440	n	3.0 / 610	tilting	Y	1/4000s	9.0/s	n	Y
5.		Olympus E-M5 II	2360	n	3.0 / 1037	swivel	Y	1/8000s	10.0/s	n	Y
6.		Pentax K-3	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	Y	Y
7.		Pentax K-3 II	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	n	Y
8.		Pentax K-5	optical	Y	3.0 / 921	fixed	n	1/8000s	7.0/s	Y	Y
9.		Pentax K-30	optical	n	3.0 / 921	fixed	n	1/6000s	6.0/s	Y	Y
10.		Pentax K-50	optical	n	3.0 / 921	fixed	n	1/6000s	6.0/s	Y	Y
11.		Pentax K-500	optical	n	3.0 / 921	fixed	n	1/6000s	6.0/s	Y	Y
12.		Pentax KP	optical	n	3.0 / 921	tilting	n	1/6000s	7.0/s	Y	Y
13.		Sony A9	3686	n	3.0 / 1440	tilting	Y	1/8000s	20.0/s	n	Y
14.		Sony A77	2359	Y	3.0 / 921	full-flex	n	1/8000s	12.0/s	Y	Y
15.		Sony A99 II	2400	Y	3.0 / 1229	full-flex	n	1/8000s	12.0/s	n	Y
16.		Sony A850	optical	Y	3.0 / 922	fixed	n	1/8000s	3.0/s	n	Y
17.		Sony A900	optical	Y	3.0 / 922	fixed	n	1/8000s	5.0/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 K-5 II has one, while the A99 does not. While the built-in flash of the K-5 II is not very powerful, it can at times be useful as a fill-in light.

The Pentax K-5 II 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-5 II writes its imaging data to SDXC cards, while the A99 uses SDXC or Memory Stick PRO Duo cards. The A99 features dual card slots, which can be very useful in case a memory card fails. In contrast, the K-5 II only has one slot. The A99 supports UHS-I cards (Ultra High Speed data transfer of up to 104 MB/s), while the K-5 II 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-5 II and Sony Alpha SLT-A99 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-5 II	Y	stereo / mono	Y	-	mini	2.0	-	-	-
2.		Sony A99	Y	stereo / mono	Y	Y	mini	2.0	-	-	-
3.		Nikon Df	Y	- / -	-	-	mini	2.0	-	-	-
4.		Olympus E-M5	Y	stereo / mono	-	-	mini	2.0	-	-	-
5.		Olympus E-M5 II	Y	stereo / mono	Y	-	micro	2.0	Y	-	-
6.		Pentax K-3	Y	mono / mono	Y	Y	mini	3.0	-	-	-
7.		Pentax K-3 II	Y	mono / mono	Y	Y	mini	3.0	-	-	-
8.		Pentax K-5	Y	stereo / mono	Y	-	mini	2.0	-	-	-
9.		Pentax K-30	Y	mono / mono	-	-	-	2.0	-	-	-
10.		Pentax K-50	Y	mono / mono	-	-	micro	2.0	-	-	-
11.		Pentax K-500	Y	mono / mono	-	-	-	2.0	-	-	-
12.		Pentax KP	Y	stereo / mono	Y	-	-	2.0	Y	-	-
13.		Sony A9	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	Y
14.		Sony A77	Y	stereo / mono	Y	-	mini	2.0	-	-	-
15.		Sony A99 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	Y
16.		Sony A850	Y	- / -	-	-	mini	2.0	-	-	-
17.		Sony A900	Y	- / -	-	-	mini	2.0	-	-	-

It is notable that the A99 has a headphone jack, which makes it possible to attach external headphones and monitor the quality of sound during the recording process. The K-5 II lacks such a headphone port.

Both cameras feature a PC Sync terminal to control professional strobe lights, which will be appreciated by studio photographers.

Travel and landscape photographers will find it useful that the A99 has an internal geolocalization sensor and can record GPS coordinates in its EXIF data.

Both the K-5 II and the A99 have been discontinued, but can regularly be found used on ebay. The K-5 II was replaced by the Pentax K-3, while the A99 was followed by the Sony A99. Further information on the features and operation of the K-5 II and A99 can be found, respectively, in the Pentax K-5 II Manual (free pdf) or the online Sony A99 Manual.

Review summary

So what conclusions can be drawn? Which of the two cameras – the Pentax K-5 II or the Sony A99 – has the upper hand? Is one clearly better than the other? A synthesis of the relative strong points of each of the models is listed below.

Reasons to prefer the Pentax K-5 II:

• Brighter framing: Features an optical viewfinder for clear, lag-free composition.
• Faster burst: Shoots at higher frequency (7 vs 6 flaps/sec) to capture the decisive moment.
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• More compact: Is smaller (131x97mm vs 147x111mm) and thus needs less room in the bag.
• Longer lasting: Can take more shots (740 versus 500) on a single battery charge.
• Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
• More affordable: Was introduced into a lower priced category (61 percent cheaper at launch).

Advantages of the Sony Alpha SLT-A99:

• More detail: Has more megapixels (24 vs 16.1MP), which boosts linear resolution by 22%.
• Better image quality: Scores markedly higher (7 points) in the DXO overall evaluation.
• Richer colors: Generates noticeably more natural colors (1.2 bits more color depth).
• Better low-light sensitivity: Can shoot in dim conditions (0.3 stops ISO advantage).
• Better video: Provides higher movie framerates (1080/60p versus 1080/25p).
• 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 detailed LCD: Has a higher resolution rear screen (1229k vs 921k dots).
• More flexible LCD: Has a full-flex 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 geotagging: Features an internal GPS sensor to log localization data.
• Greater peace of mind: Features a second card slot as a backup in case of memory card failure.
• Faster buffer clearing: Has an SD card interface that supports the UHS-I standard.

If the count of relative strengths (bullet points above) is taken as a measure, the A99 is the clear winner of the contest (14 : 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 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-5 II and the Sony A99 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 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 K-5 II or the A99. 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 where reviews by experts come in. The table below provides a synthesis of the camera assessments of some of the best known photo-gear 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	Street Price
1.		Pentax K-5 II	5/5	..	..	80/100	5/5	4.5/5	Sep 2012	US$ 1 099	ebay.com
2.		Sony A99	5/5	..	..	84/100	4.5/5	4.5/5	Sep 2012	US$ 2 799	ebay.com
3.		Nikon Df	4/5	..	..	81/100	4/5	4/5	Nov 2013	US$ 2 749	ebay.com
4.		Olympus E-M5	4/5	+ +	..	80/100	4.5/5	5/5	Feb 2012	US$ 1 299	ebay.com
5.		Olympus E-M5 II	5/5	+ +	4.5/5	81/100	5/5	5/5	Feb 2015	US$ 1 099	ebay.com
6.		Pentax K-3	4/5	..	..	83/100	5/5	5/5	Oct 2013	US$ 1 299	ebay.com
7.		Pentax K-3 II	4.5/5	..	..	..	5/5	5/5	Apr 2015	US$ 1 099	ebay.com
8.		Pentax K-5	4/5	..	..	83/100	5/5	4.5/5	Sep 2010	US$ 1 099	ebay.com
9.		Pentax K-30	4/5	..	..	78/100	4.5/5	4.5/5	May 2012	US$ 849	ebay.com
10.		Pentax K-50	5/5	..	..	..	5/5	4.5/5	Jun 2013	US$ 599	ebay.com
11.		Pentax K-500	..	..	..	..	4.5/5	4.5/5	Jun 2013	US$ 549	ebay.com
12.		Pentax KP	4/5	..	3/5	82/100	5/5	4.5/5	Jan 2017	US$ 1 099	ebay.com
13.		Sony A9	5/5	+ +	4.8/5	89/100	5/5	5/5	Apr 2017	US$ 4 499	ebay.com
14.		Sony A77	5/5	91/100	..	81/100	..	5/5	Aug 2011	US$ 1 399	ebay.com
15.		Sony A99 II	..	..	4.5/5	85/100	4.5/5	4.5/5	Sep 2016	US$ 3 199	ebay.com
16.		Sony A850	3/5	..	..	75/100	..	4.5/5	Aug 2009	US$ 1 999	ebay.com
17.		Sony A900	..	+ +	..	+ +	4.5/5	5/5	Sep 2008	US$ 2 999	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. Thus, a score needs to be put into the context of the launch date and the launch price 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? In case you are interested in seeing how other cameras pair up, 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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