Pentax K-3 II vs Canon G1 X Mark III

The Pentax K-3 II and the Canon PowerShot G1 X Mark III are two enthusiast cameras that were announced, respectively, in April 2015 and October 2017. The K-3 II is a DSLR, while the G1X Mark III is a fixed lens compact. Both cameras are equipped with an APS-C sensor. The Pentax has a resolution of 24.1 megapixels, whereas the Canon 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-3 II		Canon G1 X Mark III
Digital single lens reflex		Fixed lens compact camera
Pentax K mount lenses		24-72mm f/2.8-5.6
24.1 MP – APS-C sensor		24 MP – APS-C sensor
1080/60i Video		1080/60p Video
ISO 100-51,200		ISO 100-25,600
Optical viewfinder		Electronic viewfinder (2360k dots)
3.2" LCD – 1037k dots		3.0" LCD – 1040k dots
Fixed screen (not touch-sensitive)		Swivel touchscreen
8.3 shutter flaps per second		9 shutter flaps per second
In-body stabilization		Lens-based stabilization
Weathersealed body		Weathersealed body
720 shots per battery charge		200 shots per battery charge
131 x 100 x 77 mm, 800 g		115 x 78 x 51 mm, 399 g

Check K-3 II offers at
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Check G1X Mark III offers at
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Going beyond this snapshot of core features and characteristics, what are the differences between the Pentax K-3 II and the Canon PowerShot G1 X Mark III? 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-3 II and the Canon G1 X Mark III. 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.

The K-3 II can be obtained in two different colors (black, silver), while the G1X Mark III 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 Canon G1 X Mark III is considerably smaller (32 percent) than the Pentax K-3 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 and possibly misleading, as the G1X Mark III has a lens built in, whereas the K-3 II is an interchangeable lens camera that requires a separate lens. Attaching the latter will add extra weight and bulk to the setup.

Concerning battery life, the K-3 II gets 720 shots out of its Pentax D-LI90 battery, while the G1X Mark III can take 200 images on a single charge of its Canon NB-13L 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-3 II	131 mm	100 mm	77 mm	800 g	720	Y	Apr 2015	1,099	ebay.com
2.		Canon G1 X Mark III	115 mm	78 mm	51 mm	399 g	200	Y	Oct 2017	1,299	ebay.com
3.		Canon 80D	139 mm	105 mm	79 mm	730 g	960	Y	Feb 2016	1,199	ebay.com
4.		Fujifilm X100V	128 mm	75 mm	53 mm	478 g	420	Y	Feb 2020	1,399	ebay.com
5.		Fujifilm X100F	127 mm	75 mm	52 mm	469 g	390	n	Jan 2017	1,299	ebay.com
6.		Nikon D7200	136 mm	107 mm	76 mm	765 g	1110	Y	Mar 2015	1,199	ebay.com
7.		Pentax K-3 III	135 mm	104 mm	74 mm	820 g	800	Y	Mar 2021	1,999	amazon.com
8.		Pentax KP	132 mm	101 mm	76 mm	703 g	390	Y	Jan 2017	1,099	ebay.com
9.		Pentax K-70	126 mm	93 mm	74 mm	688 g	410	Y	Jun 2016	649	ebay.com
10.		Pentax K-S2	123 mm	91 mm	73 mm	678 g	410	Y	Feb 2015	749	ebay.com
11.		Pentax K-S1	121 mm	93 mm	70 mm	558 g	410	n	Aug 2014	749	ebay.com
12.		Pentax K-3	131 mm	100 mm	77 mm	800 g	560	Y	Oct 2013	1,299	ebay.com
13.		Pentax K-5 II	131 mm	97 mm	73 mm	760 g	740	Y	Sep 2012	1,099	ebay.com
14.		Pentax K-5	131 mm	97 mm	73 mm	760 g	740	Y	Sep 2010	1,099	ebay.com
15.		Sony A6300	120 mm	67 mm	49 mm	404 g	400	Y	Feb 2016	999	ebay.com
16.		Sony A6500	120 mm	67 mm	53 mm	453 g	350	Y	Oct 2016	1,399	ebay.com
17.		Sony A77 II	143 mm	104 mm	81 mm	647 g	480	Y	May 2014	1,199	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 manufacturer’s suggested retail prices give an idea on the placement of the camera in the maker’s lineup and the broader market. 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. 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. 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.

Both cameras under consideration feature an APS-C sensor, but their sensors differ slightly in size. The sensor area in the G1X Mark III is 10 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.

With 24.1MP, the K-3 II offers a slightly higher resolution than the G1X Mark III (24MP), but the K-3 II nevertheless has larger individual pixels (pixel pitch of 3.90μm versus 3.72μm for the G1X Mark III) due to its larger sensor. However, the G1X Mark III is a much more recent model (by 2 years and 5 months) than the K-3 II, 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 II has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

The G1X Mark III has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.

Unlike the G1X Mark III, the K-3 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-3 II has a native sensitivity range from ISO 100 to ISO 51200. The corresponding ISO settings for the Canon PowerShot G1 X Mark III are ISO 100 to ISO 25600 (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.

For many cameras, data on sensor performance has been reported by DXO Mark. 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"). 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-3 II	APS-C	24.1	6016	4000	1080/60i	23.6	13.6	1106	80
2.		Canon G1 X Mark III	APS-C	24.0	6000	4000	1080/60p	23.8	13.2	1649	81
3.		Canon 80D	APS-C	24.0	6000	4000	1080/60p	23.6	13.2	1135	79
4.		Fujifilm X100V	APS-C	26.0	6240	4160	4K/30p	24.2	13.6	1996	84
5.		Fujifilm X100F	APS-C	24.0	6000	4000	1080/60p	23.9	13.2	1704	81
6.		Nikon D7200	APS-C	24.0	6000	4000	1080/60p	24.5	14.6	1333	87
7.		Pentax K-3 III	APS-C	25.6	6192	4128	4K/30p	24.2	13.7	2083	85
8.		Pentax KP	APS-C	24.1	6016	4000	1080/60i	23.9	13.2	1699	81
9.		Pentax K-70	APS-C	24.0	6000	4000	1080/60i	23.8	13.1	1639	80
10.		Pentax K-S2	APS-C	20.0	5472	3648	1080/30p	23.6	12.9	1514	79
11.		Pentax K-S1	APS-C	20.0	5472	3648	1080/30p	23.5	13.0	1061	78
12.		Pentax K-3	APS-C	24.1	6016	4000	1080/60i	23.7	13.4	1216	80
13.		Pentax K-5 II	APS-C	16.1	4928	3264	1080/25p	23.8	14.1	1235	82
14.		Pentax K-5	APS-C	16.1	4928	3264	1080/25p	23.7	14.1	1162	82
15.		Sony A6300	APS-C	24.0	6000	4000	4K/30p	24.4	13.7	1437	85
16.		Sony A6500	APS-C	24.0	6000	4000	4K/30p	24.5	13.7	1405	85
17.		Sony A77 II	APS-C	24.0	6000	4000	1080/60p	24.4	13.4	1013	82
Note: DXO values in italics represent estimates based on sensor size and age.

Many modern cameras cannot only take still pictures, but also record videos. The two cameras under consideration both have sensors whose read-out speed is fast enough to capture moving pictures, but the G1X Mark III provides a faster frame rate than the K-3 II. It can shoot movie 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 G1X Mark III has an electronic viewfinder (2360k dots), while the K-3 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 table below summarizes some of the other core capabilities of the Pentax K-3 II and Canon G1 X Mark III 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-3 II	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	n	Y
2.		Canon G1 X Mark III	2360	n	3.0 / 1040	swivel	Y	1/2000s	9.0/s	Y	Y
3.		Canon 80D	optical	Y	3.0 / 1040	swivel	Y	1/8000s	7.0/s	Y	n
4.		Fujifilm X100V	3690	n	3.0 / 1620	tilting	Y	1/4000s	11.0/s	n	n
5.		Fujifilm X100F	2360	n	3.0 / 1040	fixed	n	1/4000s	8.0/s	Y	n
6.		Nikon D7200	optical	Y	3.2 / 1229	fixed	n	1/8000s	6.0/s	Y	n
7.		Pentax K-3 III	optical	Y	3.2 / 1620	fixed	Y	1/8000s	12.0/s	n	Y
8.		Pentax KP	optical	n	3.0 / 921	tilting	n	1/6000s	7.0/s	Y	Y
9.		Pentax K-70	optical	n	3.0 / 921	swivel	n	1/6000s	6.0/s	Y	Y
10.		Pentax K-S2	optical	n	3.0 / 921	swivel	n	1/6000s	5.4/s	Y	Y
11.		Pentax K-S1	optical	n	3.0 / 921	fixed	n	1/6000s	5.4/s	Y	Y
12.		Pentax K-3	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	Y	Y
13.		Pentax K-5 II	optical	Y	3.0 / 921	fixed	n	1/8000s	7.0/s	Y	Y
14.		Pentax K-5	optical	Y	3.0 / 921	fixed	n	1/8000s	7.0/s	Y	Y
15.		Sony A6300	2359	n	3.0 / 922	tilting	n	1/4000s	11.0/s	Y	n
16.		Sony A6500	2359	n	3.0 / 922	tilting	Y	1/4000s	11.0/s	Y	Y
17.		Sony A77 II	2359	Y	3.0 / 1229	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 feature that is present on the K-3 II, but is missing on the G1X Mark III is a top-level LCD. While being, of course, smaller than the rear screen, the control panel conveys some of the essential shooting information and can be convenient for quick and easy settings verification.

The Pentax K-3 II and the Canon G1 X Mark III 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 K-3 II and the G1X Mark III write their files to SDXC cards. The K-3 II features dual card slots, which can be very useful in case a memory card fails. In contrast, the G1X Mark III 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 Pentax K-3 II and Canon PowerShot G1 X Mark III 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-3 II	Y	mono / mono	Y	Y	mini	3.0	-	-	-
2.		Canon G1 X Mark III	Y	stereo / mono	-	-	micro	2.0	Y	Y	Y
3.		Canon 80D	Y	stereo / mono	Y	Y	mini	2.0	Y	Y	-
4.		Fujifilm X100V	Y	stereo / mono	Y	-	micro	3.1	Y	-	Y
5.		Fujifilm X100F	Y	stereo / mono	Y	-	micro	2.0	Y	-	-
6.		Nikon D7200	Y	stereo / mono	Y	Y	mini	2.0	Y	Y	-
7.		Pentax K-3 III	Y	stereo / mono	Y	Y	micro	3.2	Y	-	Y
8.		Pentax KP	Y	stereo / mono	Y	-	-	2.0	Y	-	-
9.		Pentax K-70	Y	stereo / mono	Y	-	mini	2.0	Y	-	-
10.		Pentax K-S2	Y	mono / mono	Y	-	micro	2.0	Y	Y	-
11.		Pentax K-S1	Y	stereo / mono	-	-	micro	2.0	-	-	-
12.		Pentax K-3	Y	mono / mono	Y	Y	mini	3.0	-	-	-
13.		Pentax K-5 II	Y	stereo / mono	Y	-	mini	2.0	-	-	-
14.		Pentax K-5	Y	stereo / mono	Y	-	mini	2.0	-	-	-
15.		Sony A6300	Y	stereo / mono	Y	-	micro	2.0	Y	Y	-
16.		Sony A6500	Y	stereo / mono	Y	-	micro	2.0	Y	Y	-
17.		Sony A77 II	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-

It is notable that the K-3 II has a microphone port, which is missing on the G1X Mark III. Such an external microphone input can help to substantially improve the quality of audio recordings when a good external microphone is used.

Studio photographers will appreciate that the Pentax K-3 II (unlike the G1X Mark III) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

Travel and landscape photographers will find it useful that the K-3 II has an internal geolocalization sensor and can record GPS coordinates in its EXIF data.

Both the K-3 II and the G1X Mark III have been discontinued, but can regularly be found used on ebay. The K-3 II was replaced by the Pentax K-3 III, while the G1X Mark III does not have a direct successor. Further information on the features and operation of the K-3 II and G1X Mark III can be found, respectively, in the Pentax K-3 II Manual (free pdf) or the online Canon G1 X Mark III Manual.

Review summary

So how do things add up? Is there a clear favorite between the Pentax K-3 II and the Canon G1 X Mark III? Which camera is better? Below is a summary of the relative strengths of each of the two contestants.

Reasons to prefer the Pentax K-3 II:

• 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.
• 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.
• Brighter framing: Features an optical viewfinder for clear, lag-free composition.
• Easier setting verification: Features an LCD display on top to control 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 1/2000s) to freeze action.
• More flexible: Can take a variety of interchangeable lenses, including specialty optics.
• Longer lasting: Can take more shots (720 versus 200) on a single battery charge.
• Easier geotagging: Features an internal GPS sensor to log localization data.
• 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 available for much longer (launched in April 2015).

Advantages of the Canon PowerShot G1 X Mark III:

• 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).
• Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
• More framing info: Has an electronic viewfinder that displays shooting data.
• More flexible LCD: Has a swivel screen for odd-angle shots in portrait or landscape orientation.
• Fewer buttons to press: Has a touchscreen to facilitate handling and shooting adjustments.
• More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
• Ready to shoot: Comes with an integrated lens, while the K-3 II requires a separate lens.
• More compact: Is smaller (115x78mm vs 131x100mm) and will fit more readily into a bag.
• Less heavy: Has a lower weight even though it has a lens built in (unlike the K-3 II).
• Easier fill-in: Has a small integrated flash to brighten shadows of backlit subjects.
• 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.
• Easier wireless transfer: Supports Bluetooth for image sharing without cables.
• More modern: Reflects 2 years and 5 months of technical progress since the K-3 II launch.

If the count of relative strengths (bullet points above) is taken as a measure, the match-up finishes in a tie (15 points each). However, the relative importance of the various individual camera aspects will vary according to personal preferences and needs, so that you might like to apply corresponding weights to the particular features before making a decision 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-3 II and the Canon G1 X Mark III place the cameras among the top in their class? Find out in the latest Best DSLR Camera and Best Travel-Zoom Camera listings 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 partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the K-3 II or the G1X Mark III. At times, user reviews, such as those published at amazon, address these issues in a useful manner, but such feedback is on many occasions incomplete, inconsistent, and unreliable.

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 K-3 II	4.5/5	..	..	..	5/5	5/5	Apr 2015	1,099	ebay.com
2.		Canon G1 X Mark III	5/5	+	4/5	79/100	4.5/5	4.5/5	Oct 2017	1,299	ebay.com
3.		Canon 80D	4/5	+ +	4.5/5	84/100	4.5/5	4.5/5	Feb 2016	1,199	ebay.com
4.		Fujifilm X100V	5/5	+ +	4.5/5	86/100	5/5	4.5/5	Feb 2020	1,399	ebay.com
5.		Fujifilm X100F	5/5	+	3.9/5	83/100	4.5/5	4.5/5	Jan 2017	1,299	ebay.com
6.		Nikon D7200	4/5	+ +	..	84/100	4.5/5	4.5/5	Mar 2015	1,199	ebay.com
7.		Pentax K-3 III	4/5	..	3/5	..	4.5/5	..	Mar 2021	1,999	amazon.com
8.		Pentax KP	4/5	..	3/5	82/100	5/5	4.5/5	Jan 2017	1,099	ebay.com
9.		Pentax K-70	4.5/5	..	4/5	79/100	4.5/5	4.5/5	Jun 2016	649	ebay.com
10.		Pentax K-S2	4.5/5	..	..	..	5/5	4.5/5	Feb 2015	749	ebay.com
11.		Pentax K-S1	4/5	..	..	..	4.5/5	4/5	Aug 2014	749	ebay.com
12.		Pentax K-3	4/5	..	..	83/100	5/5	5/5	Oct 2013	1,299	ebay.com
13.		Pentax K-5 II	5/5	..	..	80/100	5/5	4.5/5	Sep 2012	1,099	ebay.com
14.		Pentax K-5	4/5	..	..	83/100	5/5	4.5/5	Sep 2010	1,099	ebay.com
15.		Sony A6300	4.5/5	+	..	85/100	5/5	5/5	Feb 2016	999	ebay.com
16.		Sony A6500	5/5	+ +	3.5/5	85/100	4.5/5	4.5/5	Oct 2016	1,399	ebay.com
17.		Sony A77 II	4/5	..	..	80/100	4.5/5	5/5	May 2014	1,199	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The review scores listed above should be treated 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 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

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