Canon G15 vs Pentax K-3

The Canon PowerShot G15 and the Pentax K-3 are two digital cameras that were announced, respectively, in September 2012 and October 2013. The G15 is a fixed lens compact, while the K-3 is a DSLR. The cameras are based on a 1/1.7-inch (G15) and an APS-C (K-3) sensor. The Canon has a resolution of 12 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

Canon G15		Pentax K-3
Fixed lens compact camera		Digital single lens reflex
28-140mm f/1.8-2.8		Pentax K mount lenses
12 MP – 1/1.7" sensor		24.1 MP – APS-C sensor
1080/24p Video		1080/60i Video
ISO 80-12,800		ISO 100-51,200
Optical viewfinder		Optical viewfinder
3.0" LCD – 922k dots		3.2" LCD – 1037k dots
Fixed screen (not touch-sensitive)		Fixed screen (not touch-sensitive)
2.1 shutter flaps per second		8.3 shutter flaps per second
Lens-based stabilization		In-body stabilization
not weather sealed		Weathersealed body
350 shots per battery charge		560 shots per battery charge
107 x 76 x 40 mm, 352 g		131 x 100 x 77 mm, 800 g

Check G15 offers at
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Check K-3 offers at
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Going beyond this snapshot of core features and characteristics, what are the differences between the Canon PowerShot G15 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 physical size and weight of the Canon G15 and the Pentax K-3 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 measures are rounded to the nearest millimeter.

The K-3 can be obtained in two different colors (black, silver), while the G15 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 Pentax K-3 is considerably larger (61 percent) than the Canon G15. It is noteworthy in this context that the K-3 is splash and dust-proof, while the G15 does not feature any corresponding weather-sealing.

The above size and weight comparisons are to some extent incomplete and possibly misleading, as the G15 has a lens built in, whereas the K-3 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 G15 gets 350 shots out of its Canon NB-10L battery, while the K-3 can take 560 images on a single charge of its Pentax D-LI90 power pack.

The adjacent table lists the principal physical characteristics of the two cameras alongside a wider set of alternatives. If you want to switch the focus of the display and review another camera pair, you can move across to the CAM-parator tool and choose from the broad selection of possible camera comparisons there.

Body Specifications

		Camera Model	Camera Width	Camera Height	Camera Depth	Camera Weight	Battery Life	Weather Sealing	Camera Launch	Launch Price	Street Price
1.		Canon G15	107 mm	76 mm	40 mm	352 g	350	n	Sep 2012	US$ 499	ebay.com
2.		Pentax K-3	131 mm	100 mm	77 mm	800 g	560	Y	Oct 2013	US$ 1 299	ebay.com
3.		Canon 70D	139 mm	104 mm	79 mm	755 g	920	Y	Jul 2013	US$ 1 199	ebay.com
4.		Canon G12	112 mm	76 mm	48 mm	401 g	370	n	Sep 2010	US$ 499	ebay.com
5.		Canon G16	109 mm	76 mm	40 mm	356 g	360	n	Aug 2013	US$ 549	ebay.com
6.		Canon S120	100 mm	59 mm	29 mm	217 g	230	n	Aug 2013	US$ 449	ebay.com
7.		Canon SX50	123 mm	87 mm	106 mm	595 g	315	n	Sep 2012	US$ 429	ebay.com
8.		Canon SX60	128 mm	93 mm	114 mm	650 g	340	n	Sep 2014	US$ 549	ebay.com
9.		Fujifilm X10	117 mm	70 mm	57 mm	350 g	270	n	Sep 2011	US$ 599	ebay.com
10.		Fujifilm X20	117 mm	70 mm	57 mm	353 g	270	n	Jan 2013	US$ 599	ebay.com
11.		Nikon P7800	119 mm	78 mm	50 mm	399 g	350	n	Sep 2013	US$ 549	ebay.com
12.		Panasonic FZ150	124 mm	82 mm	92 mm	528 g	410	n	Aug 2011	US$ 499	ebay.com
13.		Panasonic LX7	111 mm	68 mm	46 mm	298 g	330	n	Jul 2012	US$ 499	ebay.com
14.		Pentax K-3 II	131 mm	100 mm	77 mm	800 g	720	Y	Apr 2015	US$ 1 099	ebay.com
15.		Pentax K-5	131 mm	97 mm	73 mm	760 g	740	Y	Sep 2010	US$ 1 099	ebay.com
16.		Pentax K-5 II	131 mm	97 mm	73 mm	760 g	740	Y	Sep 2012	US$ 1 099	ebay.com
17.		Pentax KP	132 mm	101 mm	76 mm	703 g	390	Y	Jan 2017	US$ 1 099	ebay.com
Note: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.
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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. The G15 was launched at a lower price than the K-3, despite having a lens built in. 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. 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. 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. Further, a large sensor camera will give the photographer additional creative options when using shallow depth-of-field to isolate a subject from its 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 Canon G15 features a 1/1.7-inch sensor and the Pentax K-3 an APS-C sensor. The sensor area in the K-3 is 753 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 4.6 and 1.5. The sensor in the G15 has a native 4:3 aspect ratio, while the one in the K-3 offers a 3:2 aspect.

With 24.1MP, the K-3 offers a higher resolution than the G15 (12MP), but the K-3 nevertheless has larger individual pixels (pixel pitch of 3.90μm versus 1.89μm for the G15) due to its larger sensor. Moreover, the K-3 is a somewhat more recent model (by 1 year) than the G15, and its sensor might have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixel-units. 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 resolution advantage of the Pentax K-3 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the K-3 for good quality output (200 dots per inch) amounts to 30.1 x 20 inches or 76.4 x 50.8 cm, for very good quality (250 dpi) 24.1 x 16 inches or 61.1 x 40.6 cm, and for excellent quality (300 dpi) 20.1 x 13.3 inches or 50.9 x 33.9 cm. The corresponding values for the Canon G15 are 20 x 15 inches or 50.8 x 38.1 cm for good quality, 16 x 12 inches or 40.6 x 30.5 cm for very good quality, and 13.3 x 10 inches or 33.9 x 25.4 cm for excellent quality prints.

The Canon PowerShot G15 has a native sensitivity range from ISO 80 to ISO 12800. 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.

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"). Of the two cameras under consideration, the K-3 offers substantially better image quality than the G15 (overall score 34 points higher). The advantage is based on 3.8 bits higher color depth, 1.9 EV in additional dynamic range, and 2.9 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.		Canon G15	1/1.7	12.0	4000	3000	1080/24p	19.9	11.5	165	46
2.		Pentax K-3	APS-C	24.1	6016	4000	1080/60i	23.7	13.4	1216	80
3.		Canon 70D	APS-C	20.0	5472	3648	1080/30p	22.5	11.6	926	68
4.		Canon G12	1/1.7	10.0	3648	2736	720/24p	20.4	11.2	161	47
5.		Canon G16	1/1.7	12.0	4000	3000	1080/60p	21.0	11.7	230	54
6.		Canon S120	1/1.7	12.0	4000	3000	1080/60p	21.3	11.9	246	56
7.		Canon SX50	1/2.3	12.0	4000	3000	1080/24p	20.3	11.2	179	47
8.		Canon SX60	1/2.3	14.2	4608	3072	1080/60p	19.2	10.8	127	39
9.		Fujifilm X10	2/3	12.0	4000	3000	1080/30p	20.5	11.3	245	50
10.		Fujifilm X20	2/3	12.0	4000	3000	1080/60p	20.1	10.9	-462	46
11.		Nikon P7800	1/1.7	12.0	4000	3000	1080/30p	21.2	11.7	200	54
12.		Panasonic FZ150	1/2.3	12.0	4000	3000	1080/60p	19.4	10.9	132	40
13.		Panasonic LX7	1/1.7	10.0	3648	2736	1080/60p	20.7	11.7	147	50
14.		Pentax K-3 II	APS-C	24.1	6016	4000	1080/60i	23.6	13.6	1106	80
15.		Pentax K-5	APS-C	16.1	4928	3264	1080/25p	23.7	14.1	1162	82
16.		Pentax K-5 II	APS-C	16.1	4928	3264	1080/25p	23.8	14.1	1235	82
17.		Pentax KP	APS-C	24.1	6016	4000	1080/60i	23.9	13.2	1699	81
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 K-3 provides a faster frame rate than the G15. It can shoot movie footage at 1080/60i, while the Canon is limited to 1080/24p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. The G15 and the K-3 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 table below summarizes some of the other core capabilities of the Canon G15 and Pentax K-3 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.		Canon G15	optical	n	3.0 / 922	fixed	n	1/4000s	2.1/s	Y	Y
2.		Pentax K-3	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	Y	Y
3.		Canon 70D	optical	Y	3.0 / 1040	swivel	Y	1/8000s	7.0/s	Y	n
4.		Canon G12	optical	n	2.8 / 461	swivel	n	1/4000s	1.1/s	Y	Y
5.		Canon G16	optical	n	3.0 / 922	fixed	n	1/4000s	2.2/s	Y	Y
6.		Canon S120	none	n	3.0 / 922	fixed	Y	1/2000s	12.1/s	Y	Y
7.		Canon SX50	202	n	3.0 / 461	swivel	n	1/2000s	2.2/s	Y	Y
8.		Canon SX60	922	n	3.0 / 922	swivel	n	1/2000s	6.4/s	Y	Y
9.		Fujifilm X10	optical	n	2.8 / 460	fixed	n	1/4000s	10.0/s	Y	Y
10.		Fujifilm X20	optical	n	2.8 / 460	fixed	n	1/4000s	12.0/s	Y	Y
11.		Nikon P7800	921	n	3.0 / 921	swivel	n	1/4000s	8.0/s	Y	Y
12.		Panasonic FZ150	202	n	3.0 / 460	swivel	n	1/2000s	12.0/s	Y	Y
13.		Panasonic LX7	optional	n	3.0 / 920	fixed	n	1/4000s	11.0/s	Y	Y
14.		Pentax K-3 II	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	n	Y
15.		Pentax K-5	optical	Y	3.0 / 921	fixed	n	1/8000s	7.0/s	Y	Y
16.		Pentax K-5 II	optical	Y	3.0 / 921	fixed	n	1/8000s	7.0/s	Y	Y
17.		Pentax KP	optical	n	3.0 / 921	tilting	n	1/6000s	7.0/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, but is missing on the G15 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 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.

Concerning the storage of imaging data, both the G15 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 G15 only has one slot. The K-3 supports UHS-I cards (Ultra High Speed data transfer of up to 104 MB/s), while the G15 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 Canon PowerShot G15 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.		Canon G15	Y	stereo / mono	-	-	mini	2.0	-	-	-
2.		Pentax K-3	Y	mono / mono	Y	Y	mini	3.0	-	-	-
3.		Canon 70D	Y	stereo / mono	Y	-	mini	2.0	Y	-	-
4.		Canon G12	Y	stereo / mono	-	-	mini	2.0	-	-	-
5.		Canon G16	Y	stereo / mono	-	-	mini	2.0	Y	-	-
6.		Canon S120	-	stereo / mono	-	-	mini	2.0	Y	-	-
7.		Canon SX50	Y	stereo / mono	-	-	mini	2.0	-	-	-
8.		Canon SX60	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
9.		Fujifilm X10	Y	stereo / mono	-	-	mini	2.0	-	-	-
10.		Fujifilm X20	Y	stereo / mono	-	-	micro	2.0	-	-	-
11.		Nikon P7800	Y	stereo / mono	Y	-	mini	2.0	-	-	-
12.		Panasonic FZ150	Y	stereo / -	-	-	mini	2.0	-	-	-
13.		Panasonic LX7	Y	stereo / mono	-	-	mini	2.0	-	-	-
14.		Pentax K-3 II	Y	mono / mono	Y	Y	mini	3.0	-	-	-
15.		Pentax K-5	Y	stereo / mono	Y	-	mini	2.0	-	-	-
16.		Pentax K-5 II	Y	stereo / mono	Y	-	mini	2.0	-	-	-
17.		Pentax KP	Y	stereo / mono	Y	-	-	2.0	Y	-	-

It is notable that the K-3 has a microphone port, which can help to improve the quality of audio recordings by attaching an external microphone. The G15 does not feature such a mic input.

Studio photographers will appreciate that the Pentax K-3 (unlike the G15) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

Both the G15 and the K-3 have been discontinued, but can regularly be found used on ebay. The G15 was replaced by the Canon G16, while the K-3 was followed by the Pentax K-3 II. Further information on the features and operation of the G15 and K-3 can be found, respectively, in the Canon G15 Manual (free pdf) or the online Pentax K-3 Manual.

Review summary

So what conclusions can be drawn? Which of the two cameras – the Canon G15 or the Pentax K-3 – 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 Canon PowerShot G15:

• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• Ready to shoot: Comes with a built-in lens, while the K-3 requires a separate lens.
• More compact: Is smaller (107x76mm vs 131x100mm) and thus needs less room in the bag.
• Less heavy: Is lighter even though it comes with a built-in lens (unlike the K-3).
• More affordable: Was introduced at a lower price, despite coming with a built-in lens.
• More heavily discounted: Has been on the market for longer (launched in September 2012).

Advantages of the Pentax K-3:

• More detail: Has more megapixels (24.1 vs 12MP), which boosts linear resolution by 44%.
• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• Better image quality: Scores substantially higher (34 points) in the DXO overall evaluation.
• Richer colors: Generates noticeably more natural colors (3.8 bits more color depth).
• More dynamic range: Captures a broader range of light and dark details (1.9 EV of extra DR).
• Better low-light sensitivity: Can shoot in dim conditions (2.9 stops ISO advantage).
• Better video: Provides higher movie framerates (1080/60i versus 1080/24p).
• 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 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.
• More detailed LCD: Has a higher resolution rear screen (1037k vs 922k dots).
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
• Faster burst: Shoots at higher frequency (8.3 vs 2.1 flaps/sec) to capture the decisive moment.
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• More flexible: Makes it possible to change lenses and thus to use specialty optics.
• Longer lasting: Gets more shots (560 versus 350) out of a single battery charge.
• Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
• 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.
• Faster buffer clearing: Has an SD card interface that supports the UHS-I standard.
• More modern: Was introduced somewhat (1 year) more recently.

If the count of relative strengths (bullet points above) is taken as a measure, the K-3 is the clear winner of the contest (23 : 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 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 Canon G15 and the Pentax K-3 place the cameras among the top in their class? Find out in the latest Best Travel-Zoom 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 remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the G15 or the K-3. 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.		Canon G15	4/5	+	..	76/100	4.5/5	4.5/5	Sep 2012	US$ 499	ebay.com
2.		Pentax K-3	4/5	..	..	83/100	5/5	5/5	Oct 2013	US$ 1 299	ebay.com
3.		Canon 70D	5/5	+ +	..	83/100	4.5/5	5/5	Jul 2013	US$ 1 199	ebay.com
4.		Canon G12	4/5	+	..	73/100	4.5/5	4.5/5	Sep 2010	US$ 499	ebay.com
5.		Canon G16	4/5	+	..	..	4.5/5	4.5/5	Aug 2013	US$ 549	ebay.com
6.		Canon S120	..	+ +	..	..	4.5/5	4.5/5	Aug 2013	US$ 449	ebay.com
7.		Canon SX50	3/5	+ +	..	72/100	4.5/5	4.5/5	Sep 2012	US$ 429	ebay.com
8.		Canon SX60	3/5	+ +	..	75/100	4/5	4.5/5	Sep 2014	US$ 549	ebay.com
9.		Fujifilm X10	..	..	..	76/100	4/5	4.5/5	Sep 2011	US$ 599	ebay.com
10.		Fujifilm X20	4/5	+ +	..	77/100	4.5/5	5/5	Jan 2013	US$ 599	ebay.com
11.		Nikon P7800	3/5	..	..	..	4/5	4.5/5	Sep 2013	US$ 549	ebay.com
12.		Panasonic FZ150	3/5	+ +	..	76/100	4/5	4.5/5	Aug 2011	US$ 499	ebay.com
13.		Panasonic LX7	3/5	+ +	..	75/100	4/5	4.5/5	Jul 2012	US$ 499	ebay.com
14.		Pentax K-3 II	4.5/5	..	..	..	5/5	5/5	Apr 2015	US$ 1 099	ebay.com
15.		Pentax K-5	4/5	..	..	83/100	5/5	4.5/5	Sep 2010	US$ 1 099	ebay.com
16.		Pentax K-5 II	5/5	..	..	80/100	5/5	4.5/5	Sep 2012	US$ 1 099	ebay.com
17.		Pentax KP	4/5	..	3/5	82/100	5/5	4.5/5	Jan 2017	US$ 1 099	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The above review scores should be interpreted with care, though. The ratings are only valid when referring to cameras in the same category and of the same age. 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, 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

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