Pentax K-1 II vs Sony A900

The Pentax K-1 II and the Sony Alpha A900 are two digital cameras that were announced, respectively, in February 2018 and September 2008. Both are DSLR (Digital Single Lens Reflex) cameras that are equipped with a full frame sensor. The Pentax has a resolution of 36.2 megapixels, whereas the Sony provides 24.4 MP.

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

Headline Specifications

Pentax K-1 II		Sony A900
Digital single lens reflex		Digital single lens reflex
Pentax K mount lenses		Sony A mount lenses
36.2 MP – Full Frame sensor		24.4 MP – Full Frame sensor
1080/60i Video		no Video
ISO 100-819,200		ISO 200-3,200 (100 - 6,400)
Optical viewfinder		Optical viewfinder
3.2" LCD – 1037k dots		3.0" LCD – 922k dots
Fully flexible screen (no touchscreen)		Fixed screen (not touch-sensitive)
4.4 shutter flaps per second		5 shutter flaps per second
In-body stabilization		In-body stabilization
Weathersealed body		Weathersealed body
670 shots per battery charge		880 shots per battery charge
137 x 110 x 86 mm, 1010 g		156 x 117 x 82 mm, 895 g

Check K-1 II price at
amazon.com
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ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Pentax K-1 II and the Sony Alpha A900? 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 K-1 II and the Sony A900. The two cameras are presented according to their relative size. Three successive views from the front, the top, and the rear are shown. All width, height and depth measures are rounded to the nearest millimeter.

The K-1 II can be obtained in two different colors (black, silver), while the A900 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 Sony A900 is notably larger (21 percent) than the Pentax K-1 II. However, the A900 is markedly lighter (11 percent) than the K-1 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-1 II gets 670 shots out of its Pentax D-LI90 battery, while the A900 can take 880 images on a single charge of its Sony NP-FM500H power pack.

The following table provides a synthesis of the main physical specifications of the two cameras and other similar ones. 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-1 II	137 mm	110 mm	86 mm	1010 g	670	Y	Feb 2018	1,999	amazon.com
2.		Sony A900	156 mm	117 mm	82 mm	895 g	880	Y	Sep 2008	2,999	ebay.com
3.		Canon R	139 mm	98 mm	84 mm	660 g	370	Y	Sep 2018	2,299	ebay.com
4.		Nikon Z6	134 mm	101 mm	67 mm	675 g	310	Y	Aug 2018	1,999	ebay.com
5.		Panasonic S1	149 mm	110 mm	97 mm	1017 g	400	Y	Feb 2019	2,499	amazon.com
6.		Panasonic S1R	149 mm	110 mm	97 mm	1016 g	380	Y	Feb 2019	3,699	amazon.com
7.		Panasonic S1H	151 mm	114 mm	110 mm	1052 g	400	Y	May 2019	3,999	amazon.com
8.		Pentax K-1	137 mm	110 mm	86 mm	1010 g	760	Y	Feb 2016	1,799	ebay.com
9.		Sony A7 III	127 mm	96 mm	74 mm	650 g	610	Y	Feb 2018	1,999	amazon.com
10.		Sony A7R III	127 mm	96 mm	74 mm	650 g	650	Y	Oct 2017	3,199	ebay.com
11.		Sony A9	127 mm	96 mm	63 mm	673 g	650	Y	Apr 2017	4,499	ebay.com
12.		Sony A99 II	143 mm	104 mm	76 mm	849 g	490	Y	Sep 2016	3,199	ebay.com
13.		Sony A7S II	127 mm	96 mm	60 mm	627 g	370	Y	Sep 2015	2,999	ebay.com
14.		Sony A99	147 mm	111 mm	78 mm	812 g	500	Y	Sep 2012	2,799	ebay.com
15.		Sony A850	156 mm	117 mm	82 mm	895 g	880	Y	Aug 2009	1,999	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

Any camera decision will obviously take relative prices into account. The listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The K-1 II was launched at a markedly lower price (by 33 percent) than the A900, 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 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 associated with larger, more expensive camera bodies and lenses.

Both cameras under consideration feature a full frame sensor and have a format factor (sometimes also referred to as "crop factor") of 1.0. Within the spectrum of camera sensors, this places the review cameras among the large-sensor cameras that aim for top notch image quality. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

While the two cameras under review share the same sensor size, the K-1 II offers a higher resolution of 36.2 megapixels, compared with 24.4 MP of the A900. This megapixels advantage translates into a 22 percent gain in linear resolution. On the other hand, these sensor specs imply that the K-1 II has a higher pixel density and a smaller size of the individual pixel (with a pixel pitch of 4.88μm versus 5.94μm for the A900). In this context, it should be noted, however, that the K-1 II is much more recent (by 9 years and 5 months) than the A900, and its sensor will have benefitted from technological advances during this time that compensate for the smaller pixel size. Coming back to sensor resolution, it should be mentioned that the K-1 II has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

The resolution advantage of the Pentax K-1 II implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the K-1 II for good quality output (200 dots per inch) amounts to 36.8 x 24.6 inches or 93.5 x 62.4 cm, for very good quality (250 dpi) 29.4 x 19.6 inches or 74.8 x 49.9 cm, and for excellent quality (300 dpi) 24.5 x 16.4 inches or 62.3 x 41.6 cm. The corresponding values for the Sony A900 are 30.2 x 20.2 inches or 76.8 x 51.2 cm for good quality, 24.2 x 16.1 inches or 61.4 x 41 cm for very good quality, and 20.2 x 13.4 inches or 51.2 x 34.1 cm for excellent quality prints.

Unlike the A900, the K-1 II has the capacity to capture high quality composite images by combining multiple shots after shifting its sensor by miniscule distances. This multi-shot, pixel-shift mode is most suitable for photography of stationary objects (landscapes, studio scenes).

The Pentax K-1 II has a native sensitivity range from ISO 100 to ISO 819200. The corresponding ISO settings for the Sony Alpha A900 are ISO 200 to ISO 3200, with the possibility to increase the ISO range to 100-6400.

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 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 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-1 II	Full Frame	36.2	7360	4912	1080/60i	25.1	14.0	2698	93
2.		Sony A900	Full Frame	24.4	6048	4032	none	23.7	12.3	1431	79
3.		Canon R	Full Frame	30.1	6720	4480	4K/30p	24.5	13.5	2742	89
4.		Nikon Z6	Full Frame	24.3	6048	4024	4K/30p	25.3	14.3	3299	95
5.		Panasonic S1	Full Frame	24.0	6000	4000	4K/60p	25.2	14.5	3333	95
6.		Panasonic S1R	Full Frame	46.7	8368	5584	4K/60p	26.4	14.1	3525	100
7.		Panasonic S1H	Full Frame	24.0	6000	4000	6K/30p	25.2	14.2	2805	94
8.		Pentax K-1	Full Frame	36.2	7360	4912	1080/60i	25.4	14.6	3280	96
9.		Sony A7 III	Full Frame	24.0	6000	4000	4K/30p	25.0	14.7	3730	96
10.		Sony A7R III	Full Frame	42.2	7952	5304	4K/30p	26.0	14.7	3523	100
11.		Sony A9	Full Frame	24.0	6000	4000	4K/30p	24.9	13.3	3517	92
12.		Sony A99 II	Full Frame	42.2	7952	5304	4K/30p	25.4	13.4	2317	92
13.		Sony A7S II	Full Frame	12.0	4240	2832	4K/30p	23.6	13.3	2993	85
14.		Sony A99	Full Frame	24.0	6000	4000	1080/60p	25.0	14.0	1555	89
15.		Sony A850	Full Frame	24.4	6048	4032	none	23.8	12.2	1415	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 can also record movies. The K-1 II indeed provides movie recording capabilities, while the A900 does not. The highest resolution format that the K-1 II can use is 1080/60i.

Feature comparison

Apart from body and sensor, cameras can and do differ across a range of features. The K-1 II and the A900 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%), but the viewfinder of the A900 has a higher magnification than the one of the K-1 II (0.74x vs 0.70x), 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-1 II and Sony A900 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-1 II	optical	Y	3.2 / 1037	full-flex	n	1/8000s	4.4/s	n	Y
2.		Sony A900	optical	Y	3.0 / 922	fixed	n	1/8000s	5.0/s	n	Y
3.		Canon R	3690	Y	3.2 / 2100	swivel	Y	1/8000s	8.0/s	n	n
4.		Nikon Z6	3690	Y	3.2 / 2100	tilting	Y	1/8000s	12.0/s	n	Y
5.		Panasonic S1	5760	Y	3.2 / 2100	full-flex	Y	1/8000s	9.0/s	n	Y
6.		Panasonic S1R	5760	Y	3.2 / 2100	full-flex	Y	1/8000s	9.0/s	n	Y
7.		Panasonic S1H	5760	Y	3.2 / 2330	swivel	Y	1/8000s	9.0/s	n	Y
8.		Pentax K-1	optical	Y	3.2 / 1037	full-flex	n	1/8000s	4.4/s	n	Y
9.		Sony A7 III	2359	n	3.0 / 922	tilting	Y	1/8000s	10.0/s	n	Y
10.		Sony A7R III	3686	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
11.		Sony A9	3686	n	3.0 / 1440	tilting	Y	1/8000s	20.0/s	n	Y
12.		Sony A99 II	2400	Y	3.0 / 1229	full-flex	n	1/8000s	12.0/s	n	Y
13.		Sony A7S II	2400	n	3.0 / 1229	tilting	n	1/8000s	5.0/s	n	Y
14.		Sony A99	2359	Y	3.0 / 1229	full-flex	n	1/8000s	6.0/s	n	Y
15.		Sony A850	optical	Y	3.0 / 922	fixed	n	1/8000s	3.0/s	n	Y
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

The Pentax K-1 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-1 II writes its imaging data to SDXC cards, while the A900 uses Compact Flash or Memory Stick PRO Duo cards. Both cameras feature dual card slots, which can be very useful in case a memory card fails.

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-1 II and Sony Alpha A900 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-1 II	Y	stereo / mono	Y	Y	micro	2.0	Y	-	-
2.		Sony A900	Y	- / -	-	-	mini	2.0	-	-	-
3.		Canon R	Y	stereo / mono	Y	Y	mini	3.1	Y	-	Y
4.		Nikon Z6	Y	stereo / mono	Y	Y	micro	3.1	Y	-	Y
5.		Panasonic S1	Y	stereo / mono	Y	Y	full	3.1	Y	-	Y
6.		Panasonic S1R	Y	stereo / mono	Y	Y	full	3.1	Y	-	Y
7.		Panasonic S1H	Y	stereo / mono	Y	Y	full	3.1	Y	-	Y
8.		Pentax K-1	Y	stereo / mono	Y	Y	micro	2.0	Y	-	-
9.		Sony A7 III	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
10.		Sony A7R III	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
11.		Sony A9	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	Y
12.		Sony A99 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	Y
13.		Sony A7S II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
14.		Sony A99	Y	stereo / mono	Y	Y	mini	2.0	-	-	-
15.		Sony A850	Y	- / -	-	-	mini	2.0	-	-	-

It is notable that the K-1 II offers wifi support, while the A900 does not. Wifi can be a very convenient means to transfer image data to an off-camera location.

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 K-1 II has an internal geolocalization sensor and can record GPS coordinates in its EXIF data.

The K-1 II is a recent model that features in the current product line-up of Pentax. In contrast, the A900 has been discontinued (but can be found pre-owned on ebay). As a replacement in the same line of cameras, the A900 was succeeded by the Sony A99. Further information on the features and operation of the K-1 II and A900 can be found, respectively, in the Pentax K-1 II Manual (free pdf) or the online Sony A900 Manual.

Review summary

So what is the bottom line? Is there a clear favorite between the Pentax K-1 II and the Sony A900? Which camera is better? A synthesis of the relative strong points of each of the models is listed below.

Advantages of the Pentax K-1 II:

• More detail: Offers more megapixels (36.2 vs 24.4MP) with a 22% higher linear resolution.
• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• High quality composites: Can combine several shots after pixel-shifting its sensor.
• Broader imaging potential: Can record not only still images but also 1080/60i movies.
• Larger screen: Has a bigger rear LCD (3.2" vs 3.0") for image review and settings control.
• More detailed LCD: Has a higher resolution rear screen (1037k vs 922k dots).
• More flexible LCD: Has a full-flex screen for odd-angle shots in portrait or landscape orientation.
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• More compact: Is smaller (137x110mm vs 156x117mm) and thus needs less room in the bag.
• Easier geotagging: Features an internal GPS sensor to log localization data.
• Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
• More affordable: Was introduced into a lower priced category (33 percent cheaper at launch).
• More modern: Reflects 9 years and 5 months of technical progress since the A900 launch.

Reasons to prefer the Sony Alpha A900:

• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.74x vs 0.70x).
• Faster burst: Shoots at higher frequency (5 vs 4.4 flaps/sec) to capture the decisive moment.
• Less heavy: Has a lower weight (by 115g or 11 percent) and is thus easier to take along.
• Longer lasting: Gets more shots (880 versus 670) out of a single battery charge.
• More heavily discounted: Has been around for much longer (launched in September 2008).

If the count of relative strengths (bullet points above) is taken as a measure, the K-1 II is the clear winner of the match-up (13 : 6 points). However, the pertinence of the various camera strengths will differ across photographers, so that you might want to weigh individual camera traits according to their importance for your own imaging needs before making a camera decision. 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 Pentax K-1 II and the Sony A900 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 remains incomplete and does no justice, for example, to the way the K-1 II or the A900 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 hands-on reviews by experts are important. 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 (USD)	Street Price
1.		Pentax K-1 II	..	..	4.5/5	79/100	4.5/5	4.5/5	Feb 2018	1,999	amazon.com
2.		Sony A900	..	+ +	..	+ +	4.5/5	5/5	Sep 2008	2,999	ebay.com
3.		Canon R	4/5	o	4/5	79/100	4.5/5	4/5	Sep 2018	2,299	ebay.com
4.		Nikon Z6	5/5	..	5/5	89/100	4.5/5	5/5	Aug 2018	1,999	ebay.com
5.		Panasonic S1	4.5/5	+ +	4.5/5	88/100	4.5/5	4/5	Feb 2019	2,499	amazon.com
6.		Panasonic S1R	4.5/5	..	4.6/5	89/100	4.5/5	4.5/5	Feb 2019	3,699	amazon.com
7.		Panasonic S1H	..	..	4/5	90/100	..	..	May 2019	3,999	amazon.com
8.		Pentax K-1	5/5	..	..	84/100	5/5	5/5	Feb 2016	1,799	ebay.com
9.		Sony A7 III	..	+ +	4.5/5	89/100	5/5	5/5	Feb 2018	1,999	amazon.com
10.		Sony A7R III	..	+ +	4/5	90/100	4.5/5	5/5	Oct 2017	3,199	ebay.com
11.		Sony A9	5/5	+ +	4.8/5	89/100	5/5	5/5	Apr 2017	4,499	ebay.com
12.		Sony A99 II	..	..	4.5/5	85/100	4.5/5	4.5/5	Sep 2016	3,199	ebay.com
13.		Sony A7S II	5/5	+	..	..	4.5/5	5/5	Sep 2015	2,999	ebay.com
14.		Sony A99	5/5	..	..	84/100	4.5/5	4.5/5	Sep 2012	2,799	ebay.com
15.		Sony A850	3/5	..	..	75/100	..	4.5/5	Aug 2009	1,999	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.

Check K-1 II price at
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Check A900 offers at
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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. 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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