Canon G9 X Mark II vs Sony A77

The Canon PowerShot G9 X Mark II and the Sony Alpha SLT-A77 are two digital cameras that were announced, respectively, in January 2017 and August 2011. The G9X Mark II is a fixed lens compact, while the A77 is a DSLR. The cameras are based on an one-inch (G9X Mark II) and an APS-C (A77) sensor. The Canon has a resolution of 20 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

Canon G9 X Mark II		Sony A77
Fixed lens compact camera		Digital single lens reflex
28-84mm f/2.0-4.9		Sony A mount lenses
20 MP – 1" sensor		24 MP – APS-C sensor
1080/60p Video		1080/60p Video
ISO 125-12,800		ISO 100-16,000 (50 - 25,600)
No viewfinder, LCD framing		Electronic viewfinder (2359k dots)
3.0" LCD – 1040k dots		3.0" LCD – 921k dots
Fixed touchscreen		Fully flexible screen (no touchscreen)
8.2 shutter flaps per second		12 shutter flaps per second
Lens-based stabilization		In-body stabilization
not weather sealed		Weathersealed body
235 shots per battery charge		470 shots per battery charge
98 x 58 x 31 mm, 206 g		143 x 104 x 81 mm, 732 g

Check G9X Mark II offers at
ebay.com
Check A77 offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Canon PowerShot G9 X Mark II and the Sony Alpha SLT-A77? 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 Canon G9 X Mark II and the Sony A77 is provided in the side-by-side display below. The two cameras are presented according to their relative size. Three consecutive perspectives from the front, the top, and the back are available. All size dimensions are rounded to the nearest millimeter.

The G9X Mark II can be obtained in two different colors (black, silver), while the A77 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 A77 is considerably larger (162 percent) than the Canon G9 X Mark II. It is noteworthy in this context that the A77 is splash and dust-proof, while the G9X Mark II does not feature any corresponding weather-sealing.

The above size and weight comparisons are to some extent incomplete and possibly misleading, as the G9X Mark II has a lens built in, whereas the A77 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 G9X Mark II gets 235 shots out of its Canon NB-13L battery, while the A77 can take 470 images on a single charge of its Sony NP-FM500H power pack. The power pack in the G9X Mark II can be charged via the USB port, so that it is not always necessary to take the battery charger along when travelling.

The table below summarizes the key physical specs of the two cameras alongside a broader set of comparators. 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.		Canon G9 X Mark II	98 mm	58 mm	31 mm	206 g	235	n	Jan 2017	529	ebay.com
2.		Sony A77	143 mm	104 mm	81 mm	732 g	470	Y	Aug 2011	1,399	ebay.com
3.		Canon 2000D	129 mm	101 mm	78 mm	475 g	500	n	Feb 2018	449	amazon.com
4.		Canon SX70	127 mm	91 mm	117 mm	608 g	325	n	Sep 2018	549	amazon.com
5.		Canon 200D	122 mm	93 mm	70 mm	453 g	650	n	Jun 2017	549	ebay.com
6.		Canon M100	108 mm	67 mm	35 mm	302 g	295	n	Aug 2017	499	ebay.com
7.		Canon 1300D	129 mm	101 mm	78 mm	485 g	500	n	Mar 2016	449	ebay.com
8.		Canon SX620	97 mm	57 mm	28 mm	182 g	295	n	May 2016	279	ebay.com
9.		Canon G9 X	98 mm	58 mm	31 mm	209 g	220	n	Oct 2015	529	ebay.com
10.		Canon S120	100 mm	59 mm	29 mm	217 g	230	n	Aug 2013	449	ebay.com
11.		Panasonic GH5	139 mm	98 mm	87 mm	725 g	410	Y	Jan 2017	1,999	ebay.com
12.		Sony HX99	102 mm	58 mm	36 mm	242 g	370	n	Aug 2018	449	ebay.com
13.		Sony HX95	102 mm	58 mm	36 mm	242 g	370	n	Aug 2018	429	ebay.com
14.		Sony A9	127 mm	96 mm	63 mm	673 g	650	Y	Apr 2017	4,499	ebay.com
15.		Sony A7 II	127 mm	96 mm	60 mm	599 g	350	Y	Nov 2014	1,999	ebay.com
16.		Sony A77 II	143 mm	104 mm	81 mm	647 g	480	Y	May 2014	1,199	ebay.com
17.		Sony A99	147 mm	111 mm	78 mm	812 g	500	Y	Sep 2012	2,799	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 G9X Mark II was launched at a lower price than the A77, 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. 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. 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 are more costly to manufacture and tend to lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the Canon G9 X Mark II features an one-inch sensor and the Sony A77 an APS-C sensor. The sensor area in the A77 is 216 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 2.7 and 1.5. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

With 24MP, the A77 offers a higher resolution than the G9X Mark II (20MP), but the A77 nevertheless has larger individual pixels (pixel pitch of 3.91μm versus 2.41μm for the G9X Mark II) due to its larger sensor. However, the G9X Mark II is a much more recent model (by 5 years and 4 months) than the A77, and its sensor will have benefitted from technological advances during this time that enhance the light gathering capacity of its pixel-units.

The resolution advantage of the Sony A77 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A77 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 Canon G9 X Mark II are 27.4 x 18.2 inches or 69.5 x 46.3 cm for good quality, 21.9 x 14.6 inches or 55.6 x 37.1 cm for very good quality, and 18.2 x 12.2 inches or 46.3 x 30.9 cm for excellent quality prints.

The Canon PowerShot G9 X Mark II has a native sensitivity range from ISO 125 to ISO 12800. The corresponding ISO settings for the Sony Alpha SLT-A77 are ISO 100 to ISO 16000, with the possibility to increase the ISO range to 50-25600.

In terms of underlying technology, the G9X Mark II is build around a BSI-CMOS sensor, while the A77 uses a CMOS imager. 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"). Of the two cameras under consideration, the A77 offers substantially better image quality than the G9X Mark II (overall score 13 points higher). The advantage is based on 2.1 bits higher color depth, 0.7 EV in additional dynamic range, and 0.6 stops in additional low light sensitivity. 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.		Canon G9 X Mark II	1-inch	20.0	5472	3648	1080/60p	21.9	12.5	522	65
2.		Sony A77	APS-C	24.0	6000	4000	1080/60p	24.0	13.2	801	78
3.		Canon 2000D	APS-C	24.0	6000	4000	1080/30p	22.6	11.9	1009	71
4.		Canon SX70	1/2.3	20.2	5184	3888	4K/30p	20.6	12.1	1063	51
5.		Canon 200D	APS-C	24.0	6000	4000	1080/60p	23.6	13.4	1041	79
6.		Canon M100	APS-C	24.0	6000	4000	1080/60p	23.5	12.9	1272	78
7.		Canon 1300D	APS-C	17.9	5184	3456	1080/30p	22.0	11.7	781	66
8.		Canon SX620	1/2.3	20.2	5184	3888	1080/30p	20.4	11.8	838	49
9.		Canon G9 X	1-inch	20.0	5472	3648	1080/60p	21.5	12.3	495	63
10.		Canon S120	1/1.7	12.0	4000	3000	1080/60p	21.3	11.9	246	56
11.		Panasonic GH5	Four Thirds	20.2	5184	3888	4K/60p	23.9	13.0	807	77
12.		Sony HX99	1/2.3	18.0	4896	3672	4K/30p	20.6	12.1	1058	51
13.		Sony HX95	1/2.3	18.0	4896	3672	4K/30p	20.6	12.1	1057	51
14.		Sony A9	Full Frame	24.0	6000	4000	4K/30p	24.9	13.3	3517	92
15.		Sony A7 II	Full Frame	24.0	6000	4000	1080/60p	24.9	13.6	2449	90
16.		Sony A77 II	APS-C	24.0	6000	4000	1080/60p	24.4	13.4	1013	82
17.		Sony A99	Full Frame	24.0	6000	4000	1080/60p	25.0	14.0	1555	89
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. Both cameras under consideration are equipped with sensors that have a sufficiently high read-out speed for moving images, and both provide the same movie specifications (1080/60p).

Feature comparison

Apart from body and sensor, cameras can and do differ across a range of features. For example, the A77 has an electronic viewfinder (2359k dots), which can be very helpful when shooting in bright sunlight. In contrast, the G9X Mark II relies on live view and the rear LCD for framing. The adjacent table lists some of the other core features of the Canon G9 X Mark II and Sony A77 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.		Canon G9 X Mark II	none	n	3.0 / 1040	fixed	Y	1/2000s	8.2/s	Y	Y
2.		Sony A77	2359	Y	3.0 / 921	full-flex	n	1/8000s	12.0/s	Y	Y
3.		Canon 2000D	optical	n	3.0 / 920	fixed	n	1/4000s	3.0/s	Y	n
4.		Canon SX70	2360	n	3.0 / 922	swivel	n	1/2000s	10.0/s	Y	Y
5.		Canon 200D	optical	n	3.0 / 1040	swivel	Y	1/4000s	5.0/s	Y	n
6.		Canon M100	none	n	3.0 / 1040	tilting	Y	1/4000s	6.1/s	Y	n
7.		Canon 1300D	optical	n	3.0 / 920	fixed	n	1/4000s	3.0/s	Y	n
8.		Canon SX620	none	n	3.0 / 922	fixed	n	1/2000s	2.5/s	Y	Y
9.		Canon G9 X	none	n	3.0 / 1040	fixed	Y	1/2000s	6.0/s	Y	Y
10.		Canon S120	none	n	3.0 / 922	fixed	Y	1/2000s	12.1/s	Y	Y
11.		Panasonic GH5	3680	n	3.2 / 1620	swivel	Y	1/8000s	12.0/s	n	Y
12.		Sony HX99	638	n	3.0 / 922	tilting	Y	1/2000s	10.0/s	Y	Y
13.		Sony HX95	638	n	3.0 / 922	tilting	n	1/2000s	10.0/s	Y	Y
14.		Sony A9	3686	n	3.0 / 1440	tilting	Y	1/8000s	20.0/s	n	Y
15.		Sony A7 II	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	Y
16.		Sony A77 II	2359	Y	3.0 / 1229	full-flex	n	1/8000s	12.0/s	Y	Y
17.		Sony A99	2359	Y	3.0 / 1229	full-flex	n	1/8000s	6.0/s	n	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 G9X Mark II has a touchscreen, while the A77 has a conventional panel. Touch control can be particularly helpful, for example, for setting the focus point.

The Canon G9 X Mark 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 G9X Mark II writes its imaging data to SDXC cards, while the A77 uses SDXC or Memory Stick PRO Duo cards. 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 Canon PowerShot G9 X Mark II and Sony Alpha SLT-A77 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 G9 X Mark II	-	stereo / mono	-	-	micro	2.0	Y	Y	Y
2.		Sony A77	Y	stereo / mono	Y	-	mini	2.0	-	-	-
3.		Canon 2000D	Y	mono / mono	-	-	mini	2.0	Y	Y	-
4.		Canon SX70	-	stereo / mono	Y	-	micro	2.0	Y	-	Y
5.		Canon 200D	Y	stereo / mono	Y	-	mini	2.0	Y	Y	Y
6.		Canon M100	-	stereo / mono	-	-	micro	2.0	Y	Y	Y
7.		Canon 1300D	Y	mono / mono	-	-	mini	2.0	Y	Y	-
8.		Canon SX620	-	mono / mono	-	-	micro	2.0	Y	Y	-
9.		Canon G9 X	-	stereo / mono	-	-	micro	2.0	Y	Y	-
10.		Canon S120	-	stereo / mono	-	-	mini	2.0	Y	-	-
11.		Panasonic GH5	Y	stereo / mono	Y	Y	full	3.1	Y	-	Y
12.		Sony HX99	-	stereo / mono	-	-	micro	2.0	Y	Y	Y
13.		Sony HX95	-	stereo / mono	-	-	micro	2.0	Y	Y	Y
14.		Sony A9	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	Y
15.		Sony A7 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
16.		Sony A77 II	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
17.		Sony A99	Y	stereo / mono	Y	Y	mini	2.0	-	-	-

It is notable that the G9X Mark II offers wifi support, while the A77 does not. Wifi can be a very convenient means to transfer image data to an off-camera location.

Studio photographers will appreciate that the Sony A77 (unlike the G9X Mark II) 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 A77 has an internal geolocalization sensor and can record GPS coordinates in its EXIF data.

Both the G9X Mark II and the A77 have been discontinued, but can regularly be found used on ebay. The A77 was replaced by the Sony A77 II, while the G9X Mark II does not have a direct successor. Further information on the features and operation of the G9X Mark II and A77 can be found, respectively, in the Canon G9 X Mark II Manual (free pdf) or the online Sony A77 Manual.

Review summary

So what conclusions can be drawn? Is there a clear favorite between the Canon G9 X Mark II and the Sony A77? Which camera is better? A synthesis of the relative strong points of each of the models is listed below.

Reasons to prefer the Canon PowerShot G9 X Mark II:

• More detailed LCD: Has a higher resolution rear screen (1040k vs 921k dots).
• Fewer buttons to press: Is equipped with a touch-sensitive rear screen to facilitate handling.
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• Ready to shoot: Comes with a built-in lens, while the A77 requires a separate lens.
• More compact: Is smaller (98x58mm vs 143x104mm) and thus needs less room in the bag.
• Less heavy: Is lighter even though it comes with a built-in lens (unlike the A77).
• Easier travel charging: Can be conveniently charged via its USB port.
• 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 affordable: Was introduced at a lower price, despite coming with a built-in lens.
• More modern: Reflects 5 years and 4 months of technical progress since the A77 launch.

Arguments in favor of the Sony Alpha SLT-A77:

• More detail: Has more megapixels (24 vs 20MP), which boosts linear resolution by 10%.
• Better image quality: Scores substantially higher (13 points) in the DXO overall evaluation.
• Richer colors: Generates noticeably more natural colors (2.1 bits more color depth).
• More dynamic range: Captures a broader range of light and dark details (0.7 EV of extra DR).
• Better low-light sensitivity: Can shoot in dim conditions (0.6 stops ISO advantage).
• Better sound: Can connect to an external microphone for higher quality sound recording.
• Easier framing: Has an electronic viewfinder for image composition and settings control.
• Easier setting verification: Features a control panel on top to check shooting parameters.
• 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.
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/2000s) to freeze action.
• Faster burst: Shoots at higher frequency (12 vs 8.2 flaps/sec) to capture the decisive moment.
• More flexible: Makes it possible to change lenses and thus to use specialty optics.
• Longer lasting: Gets more shots (470 versus 235) out of a single battery charge.
• Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
• Better lighting: Features a hotshoe and can thus hold and trigger an external flash gun.
• Easier geotagging: Features an internal GPS sensor to log localization data.
• Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
• More heavily discounted: Has been around for much longer (launched in August 2011).

If the count of individual advantages (bullet points above) is taken as a guide, the A77 is the clear winner of the contest (19 : 12 points). 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 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 G9 X Mark II and the Sony A77 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 the spec-sheets of cameras can offer a general idea of their imaging potential, it remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the G9X Mark II or the A77. 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.		Canon G9 X Mark II	4/5	..	4/5	75/100	4.5/5	4.5/5	Jan 2017	529	ebay.com
2.		Sony A77	5/5	91/100	..	81/100	..	5/5	Aug 2011	1,399	ebay.com
3.		Canon 2000D	3/5	o	3.5/5	..	3.5/5	3.5/5	Feb 2018	449	amazon.com
4.		Canon SX70	..	+ +	3.5/5	..	3.5/5	3.5/5	Sep 2018	549	amazon.com
5.		Canon 200D	4/5	+ +	4/5	78/100	4.5/5	4.5/5	Jun 2017	549	ebay.com
6.		Canon M100	3/5	+	..	..	4/5	3.5/5	Aug 2017	499	ebay.com
7.		Canon 1300D	4/5	o	4/5	73/100	4/5	4/5	Mar 2016	449	ebay.com
8.		Canon SX620	..	..	..	..	..	4/5	May 2016	279	ebay.com
9.		Canon G9 X	3.5/5	+ +	..	..	4.5/5	4.5/5	Oct 2015	529	ebay.com
10.		Canon S120	..	+ +	..	..	4.5/5	4.5/5	Aug 2013	449	ebay.com
11.		Panasonic GH5	4.5/5	+ +	..	85/100	4.5/5	5/5	Jan 2017	1,999	ebay.com
12.		Sony HX99	..	..	..	..	4/5	4.5/5	Aug 2018	449	ebay.com
13.		Sony HX95	..	..	..	..	..	..	Aug 2018	429	ebay.com
14.		Sony A9	5/5	+ +	4.8/5	89/100	5/5	5/5	Apr 2017	4,499	ebay.com
15.		Sony A7 II	5/5	+	4/5	82/100	4.5/5	5/5	Nov 2014	1,999	ebay.com
16.		Sony A77 II	4/5	..	..	80/100	4.5/5	5/5	May 2014	1,199	ebay.com
17.		Sony A99	5/5	..	..	84/100	4.5/5	4.5/5	Sep 2012	2,799	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

Care should be taken when interpreting the review scores above, though. The ratings are only valid when referring to cameras in the same category and of the same age. Hence, a score should always be seen in the context of the camera's market launch date and its price, 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

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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