Fujifilm X-A3 vs Pentax K-3

The Fujifilm X-A3 and the Pentax K-3 are two digital cameras that were announced, respectively, in August 2016 and October 2013. The X-A3 is a mirrorless interchangeable lens camera, while the K-3 is a DSLR. Both cameras are equipped with an APS-C sensor. The Fujifilm has a resolution of 24 megapixels, whereas the Pentax provides 24.1 MP.

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

Headline Specifications

Fujifilm X-A3		Pentax K-3
Mirrorless system camera		Digital single lens reflex
Fujifilm X mount lenses		Pentax K mount lenses
24 MP – APS-C sensor		24.1 MP – APS-C sensor
1080/60p Video		1080/60i Video
ISO 200-6,400 (100 - 25,600)		ISO 100-51,200
No viewfinder, LCD framing		Optical viewfinder
3.0" LCD – 1040k dots		3.2" LCD – 1037k dots
Tilting touchscreen		Fixed screen (not touch-sensitive)
6 shutter flaps per second		8.3 shutter flaps per second
Lens stabilization only		In-body stabilization
not weather sealed		Weathersealed body
410 shots per battery charge		560 shots per battery charge
117 x 67 x 40 mm, 339 g		131 x 100 x 77 mm, 800 g

Check X-A3 offers at
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Check K-3 offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Fujifilm X-A3 and the Pentax K-3? 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 Fujifilm X-A3 and the Pentax K-3. 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 size dimensions are rounded to the nearest millimeter.

The X-A3 can be obtained in three different colors (silver, brown, pink), while the K-3 is available in two color-versions (black, silver).

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Pentax K-3 is considerably larger (67 percent) than the Fujifilm X-A3. Moreover, the K-3 is substantially heavier (136 percent) than the X-A3. It is noteworthy in this context that the K-3 is splash and dust-proof, while the X-A3 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.

Concerning battery life, the X-A3 gets 410 shots out of its Fujifilm NP-W126S battery, while the K-3 can take 560 images on a single charge of its Pentax D-LI90 power pack. The power pack in the X-A3 can be charged via the USB port, so that it is not always necessary to take the battery charger along when travelling.

The following table provides a synthesis of the main physical specifications of the two cameras and other similar ones. 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.		Fujifilm X-A3	117 mm	67 mm	40 mm	339 g	410	n	Aug 2016	399	ebay.com
2.		Pentax K-3	131 mm	100 mm	77 mm	800 g	560	Y	Oct 2013	1,299	ebay.com
3.		Fujifilm X-T200	121 mm	84 mm	55 mm	370 g	270	n	Jan 2020	699	ebay.com
4.		Fujifilm X-T30	118 mm	83 mm	47 mm	383 g	380	n	Feb 2019	899	ebay.com
5.		Fujifilm X-A7	119 mm	68 mm	41 mm	320 g	440	n	Sep 2019	499	ebay.com
6.		Fujifilm X-A5	117 mm	68 mm	40 mm	361 g	450	n	Jan 2018	399	ebay.com
7.		Fujifilm X-E3	121 mm	74 mm	43 mm	337 g	350	n	Sep 2017	899	ebay.com
8.		Fujifilm X-T20	118 mm	83 mm	41 mm	383 g	350	n	Jan 2017	899	ebay.com
9.		Fujifilm X-A10	117 mm	67 mm	40 mm	331 g	410	n	Dec 2016	399	ebay.com
10.		Fujifilm X-A2	117 mm	67 mm	40 mm	350 g	410	n	Jan 2015	399	ebay.com
11.		Fujifilm X-T10	118 mm	83 mm	41 mm	381 g	350	n	May 2015	799	ebay.com
12.		Fujifilm X-A1	117 mm	67 mm	39 mm	330 g	350	n	Sep 2013	399	ebay.com
13.		Nikon D7100	136 mm	107 mm	76 mm	765 g	950	Y	Feb 2013	1,199	ebay.com
14.		Pentax KP	132 mm	101 mm	76 mm	703 g	390	Y	Jan 2017	1,099	ebay.com
15.		Pentax K-3 II	131 mm	100 mm	77 mm	800 g	720	Y	Apr 2015	1,099	ebay.com
16.		Pentax K-5 II	131 mm	97 mm	73 mm	760 g	740	Y	Sep 2012	1,099	ebay.com
17.		Sony A77	143 mm	104 mm	81 mm	732 g	470	Y	Aug 2011	1,399	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 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 X-A3 was launched at a markedly lower price (by 69 percent) than the K-3, 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. Then, after the new model is out, very good deals can frequently be found on the pre-owned market.

Sensor comparison

The size of the sensor inside a digital camera is one of the key determinants 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 associated with larger, more expensive camera bodies and lenses.

Both cameras under consideration feature an APS-C sensor, but their sensors differ slightly in size. The sensor area in the K-3 is 1 percent smaller. They nevertheless have the same format factor of 1.5. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

Despite having a slightly smaller sensor, the K-3 offers a slightly higher resolution of 24.1 megapixels, compared with 24 MP of the X-A3. 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 3.90μm versus 3.92μm for the X-A3). Moreover, it should be noted that the X-A3 is much more recent (by 2 years and 10 months) than the K-3, and its sensor will have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixels. Coming back to sensor resolution, it should be mentioned that the K-3 has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

The Fujifilm X-A3 has a native sensitivity range from ISO 200 to ISO 6400, which can be extended to ISO 100-25600. The corresponding ISO settings for the Pentax K-3 are ISO 100 to ISO 51200 (no boost).

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"). 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.		Fujifilm X-A3	APS-C	24.0	6000	4000	1080/60p	23.8	13.1	1664	81
2.		Pentax K-3	APS-C	24.1	6016	4000	1080/60i	23.7	13.4	1216	80
3.		Fujifilm X-T200	APS-C	24.0	6000	4000	4K/30p	24.1	13.6	1991	84
4.		Fujifilm X-T30	APS-C	26.0	6240	4160	4K/30p	24.1	13.5	1895	83
5.		Fujifilm X-A7	APS-C	24.0	6000	4000	4K/30p	24.1	13.6	1955	84
6.		Fujifilm X-A5	APS-C	24.0	6000	4000	4K/15p	24.0	13.3	1800	82
7.		Fujifilm X-E3	APS-C	24.0	6000	4000	4K/30p	23.9	13.3	1764	82
8.		Fujifilm X-T20	APS-C	24.0	6000	4000	4K/30p	23.9	13.2	1704	81
9.		Fujifilm X-A10	APS-C	16.0	4896	3264	1080/30p	23.9	13.2	1691	81
10.		Fujifilm X-A2	APS-C	16.0	4896	3264	1080/30p	23.6	12.8	1515	79
11.		Fujifilm X-T10	APS-C	16.0	4896	3264	1080/60p	23.7	12.9	1546	79
12.		Fujifilm X-A1	APS-C	16.0	4896	3264	1080/30p	23.4	12.6	1390	76
13.		Nikon D7100	APS-C	24.0	6000	4000	1080/60p	24.2	13.7	1256	83
14.		Pentax KP	APS-C	24.1	6016	4000	1080/60i	23.9	13.2	1699	81
15.		Pentax K-3 II	APS-C	24.1	6016	4000	1080/60i	23.6	13.6	1106	80
16.		Pentax K-5 II	APS-C	16.1	4928	3264	1080/25p	23.8	14.1	1235	82
17.		Sony A77	APS-C	24.0	6000	4000	1080/60p	24.0	13.2	801	78
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 have a sensor with sufficiently fast read-out times for moving pictures, but the X-A3 provides a higher frame rate than the K-3. It can shoot video footage at 1080/60p, while the Pentax is limited to 1080/60i.

Feature comparison

Apart from body and sensor, cameras can and do differ across a range of features. For example, the K-3 has an optical viewfinder, which can be very useful when shooting in bright sunlight. In contrast, the X-A3 relies on live view and the rear LCD for framing. The adjacent table lists some of the other core features of the Fujifilm X-A3 and Pentax K-3 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.		Fujifilm X-A3	none	n	3.0 / 1040	tilting	Y	1/4000s	6.0/s	Y	n
2.		Pentax K-3	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	Y	Y
3.		Fujifilm X-T200	2360	n	3.5 / 2780	swivel	Y	1/4000s	8.0/s	Y	n
4.		Fujifilm X-T30	2360	n	3.0 / 1040	tilting	Y	1/4000s	8.0/s	Y	n
5.		Fujifilm X-A7	none	n	3.5 / 2760	swivel	Y	1/4000s	6.0/s	Y	n
6.		Fujifilm X-A5	none	n	3.0 / 1040	tilting	Y	1/4000s	6.0/s	Y	n
7.		Fujifilm X-E3	2360	n	3.0 / 1040	fixed	Y	1/4000s	8.0/s	n	n
8.		Fujifilm X-T20	2360	n	3.0 / 1040	tilting	Y	1/4000s	8.0/s	Y	n
9.		Fujifilm X-A10	none	n	3.0 / 1040	tilting	n	1/4000s	6.0/s	Y	n
10.		Fujifilm X-A2	none	n	3.0 / 920	tilting	n	1/4000s	5.6/s	Y	n
11.		Fujifilm X-T10	2360	n	3.0 / 920	tilting	n	1/4000s	8.0/s	Y	n
12.		Fujifilm X-A1	none	n	3.0 / 920	tilting	n	1/4000s	5.6/s	Y	n
13.		Nikon D7100	optical	Y	3.2 / 1229	fixed	n	1/8000s	6.0/s	Y	n
14.		Pentax KP	optical	n	3.0 / 921	tilting	n	1/6000s	7.0/s	Y	Y
15.		Pentax K-3 II	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	n	Y
16.		Pentax K-5 II	optical	Y	3.0 / 921	fixed	n	1/8000s	7.0/s	Y	Y
17.		Sony A77	2359	Y	3.0 / 921	full-flex	n	1/8000s	12.0/s	Y	Y
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One differentiating feature between the two cameras concerns the touch sensitivity of the rear screen. The X-A3 has a touchscreen, while the K-3 has a conventional panel. Touch control can be particularly helpful, for example, for setting the focus point.

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 X-A3 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 Fujifilm X-A3 and the Pentax K-3 both have 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 X-A3 and the K-3 write their files to SDXC cards. The K-3 features dual card slots, which can be very useful in case a memory card fails. In contrast, the X-A3 only has one slot. 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 Fujifilm X-A3 and Pentax K-3 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.		Fujifilm X-A3	Y	stereo / mono	-	-	micro	2.0	Y	-	-
2.		Pentax K-3	Y	mono / mono	Y	Y	mini	3.0	-	-	-
3.		Fujifilm X-T200	Y	stereo / mono	Y	Y	micro	3.1	Y	-	Y
4.		Fujifilm X-T30	Y	stereo / mono	Y	-	micro	3.1	Y	-	Y
5.		Fujifilm X-A7	Y	stereo / mono	Y	-	micro	2.0	Y	-	Y
6.		Fujifilm X-A5	Y	stereo / mono	Y	-	micro	2.0	Y	-	Y
7.		Fujifilm X-E3	Y	stereo / mono	Y	-	micro	2.0	Y	-	Y
8.		Fujifilm X-T20	Y	stereo / mono	Y	-	micro	2.0	Y	-	-
9.		Fujifilm X-A10	-	stereo / mono	-	-	micro	2.0	Y	-	-
10.		Fujifilm X-A2	Y	stereo / mono	-	-	mini	2.0	Y	-	-
11.		Fujifilm X-T10	Y	stereo / mono	Y	-	micro	2.0	Y	-	-
12.		Fujifilm X-A1	Y	stereo / mono	-	-	mini	2.0	Y	-	-
13.		Nikon D7100	Y	stereo / mono	Y	Y	mini	2.0	-	-	-
14.		Pentax KP	Y	stereo / mono	Y	-	-	2.0	Y	-	-
15.		Pentax K-3 II	Y	mono / mono	Y	Y	mini	3.0	-	-	-
16.		Pentax K-5 II	Y	stereo / mono	Y	-	mini	2.0	-	-	-
17.		Sony A77	Y	stereo / mono	Y	-	mini	2.0	-	-	-

It is notable that the X-A3 offers wifi support, while the K-3 does not. Wifi can be a very convenient means to transfer image data to an off-camera location.

Studio photographers will appreciate that the Pentax K-3 (unlike the X-A3) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

Both the X-A3 and the K-3 have been discontinued, but can regularly be found used on ebay. The K-3 was replaced by the Pentax K-3 II, while the X-A3 was followed by the Fujifilm X-A5. Further information on the features and operation of the X-A3 and K-3 can be found, respectively, in the Fujifilm X-A3 Manual (free pdf) or the online Pentax K-3 Manual.

Review summary

So what is the bottom line? Which of the two cameras – the Fujifilm X-A3 or the Pentax K-3 – has the upper hand? Is one clearly better than the other? Below is a summary of the relative strengths of each of the two contestants.

Arguments in favor of the Fujifilm X-A3:

• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• Better video: Provides higher movie framerates (1080/60p versus 1080/60i).
• More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
• Fewer buttons to press: Is equipped with a touch-sensitive rear screen to facilitate handling.
• More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
• Less disturbing: Has an electronic shutter option for completely silent shooting.
• More compact: Is smaller (117x67mm vs 131x100mm) and thus needs less room in the bag.
• Less heavy: Is lighter (by 461g or 58 percent) and hence easier to carry around.
• Easier travel charging: Can be conveniently charged via its USB port.
• More legacy lens friendly: Can take a broad range of non-native lenses via adapters.
• 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 (69 percent cheaper at launch).
• More modern: Reflects 2 years and 10 months of technical progress since the K-3 launch.

Advantages of the Pentax K-3:

• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• 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 optical viewfinder for image composition and settings control.
• Easier setting verification: Features a control panel on top to check shooting parameters.
• Larger screen: Has a bigger rear LCD (3.2" vs 3.0") for image review and settings control.
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
• Faster burst: Shoots at higher frequency (8.3 vs 6 flaps/sec) to capture the decisive moment.
• Longer lasting: Gets more shots (560 versus 410) out of a single battery charge.
• Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
• Sharper images: Has stabilization technology built-in to reduce the impact of hand-shake.
• Faster data transfer: Supports a more advanced USB protocol (3.0 vs 2.0).
• Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
• Greater peace of mind: Features a second card slot as a backup in case of memory card failure.
• More heavily discounted: Has been around for much longer (launched in October 2013).

If the number of relative strengths (bullet points above) is taken as a guide, the K-3 emerges as the winner of the match-up (15 : 13 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 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 Fujifilm X-A3 and the Pentax K-3 place the cameras among the top in their class? Find out in the latest Best Mirrorless Interchangeable Lens Camera and Best DSLR 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 says little about, for example, the shooting experience and imaging performance of the X-A3 and the K-3 in practical situations. 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 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.		Fujifilm X-A3	..	..	..	74/100	4.5/5	4/5	Aug 2016	399	ebay.com
2.		Pentax K-3	4/5	..	..	83/100	5/5	5/5	Oct 2013	1,299	ebay.com
3.		Fujifilm X-T200	3.5/5	..	4/5	82/100	4/5	4.5/5	Jan 2020	699	ebay.com
4.		Fujifilm X-T30	5/5	+ +	5/5	84/100	4.5/5	4.5/5	Feb 2019	899	ebay.com
5.		Fujifilm X-A7	3/5	..	3.5/5	81/100	4/5	3.5/5	Sep 2019	499	ebay.com
6.		Fujifilm X-A5	..	+	4.1/5	..	4/5	3.5/5	Jan 2018	399	ebay.com
7.		Fujifilm X-E3	4.5/5	+	4.5/5	84/100	4.5/5	4.5/5	Sep 2017	899	ebay.com
8.		Fujifilm X-T20	5/5	+ +	5/5	82/100	5/5	4.5/5	Jan 2017	899	ebay.com
9.		Fujifilm X-A10	..	..	..	..	4/5	4/5	Dec 2016	399	ebay.com
10.		Fujifilm X-A2	4/5	..	..	..	4.5/5	4.5/5	Jan 2015	399	ebay.com
11.		Fujifilm X-T10	4.5/5	+ +	..	80/100	5/5	5/5	May 2015	799	ebay.com
12.		Fujifilm X-A1	..	..	..	..	4.5/5	4.5/5	Sep 2013	399	ebay.com
13.		Nikon D7100	5/5	+ +	..	85/100	4.5/5	4.5/5	Feb 2013	1,199	ebay.com
14.		Pentax KP	4/5	..	3/5	82/100	5/5	4.5/5	Jan 2017	1,099	ebay.com
15.		Pentax K-3 II	4.5/5	..	..	..	5/5	5/5	Apr 2015	1,099	ebay.com
16.		Pentax K-5 II	5/5	..	..	80/100	5/5	4.5/5	Sep 2012	1,099	ebay.com
17.		Sony A77	5/5	91/100	..	81/100	..	5/5	Aug 2011	1,399	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The above review scores should be interpreted with care, though. The assessments were made in relation to similar cameras of the same technological generation. Thus, a score needs to be put into the context of the launch date and the launch price of the camera, and comparisons of ratings among very different cameras or across long time periods have little meaning. 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 would like to check on the differences and similarities of other camera models, just make your choice using the following search menu. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.

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