Sony A77 vs Panasonic G9

The Sony Alpha SLT-A77 and the Panasonic Lumix DC-G9 are two enthusiast cameras that were announced, respectively, in August 2011 and November 2017. The A77 is a DSLR, while the G9 is a mirrorless interchangeable lens camera. The cameras are based on an APS-C (A77) and a Four Thirds (G9) sensor. The Sony has a resolution of 24 megapixels, whereas the Panasonic provides 20.2 MP.

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

Headline Specifications

Sony A77		Panasonic G9
Digital single lens reflex		Mirrorless system camera
Sony A mount lenses		Micro Four Thirds lenses
24 MP – APS-C sensor		20.2 MP – Four Thirds sensor
1080/60p Video		4K/60p Video
ISO 100-16,000 (50 - 25,600)		ISO 200-25,600
Electronic viewfinder (2359k dots)		Electronic viewfinder (3680k dots)
3.0" LCD – 921k dots		3.0" LCD – 1040k dots
Fully flexible screen (no touchscreen)		Swivel touchscreen
12 shutter flaps per second		20 shutter flaps per second
In-body stabilization		In-body stabilization
Weathersealed body		Weathersealed body
470 shots per battery charge		400 shots per battery charge
143 x 104 x 81 mm, 732 g		137 x 97 x 92 mm, 658 g

Check A77 offers at
ebay.com
Check G9 offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Sony Alpha SLT-A77 and the Panasonic Lumix DC-G9? 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 Sony A77 and the Panasonic G9 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.

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Panasonic G9 is notably smaller (11 percent) than the Sony A77. Moreover, the G9 is markedly lighter (10 percent) than the A77. 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 A77 gets 470 shots out of its Sony NP-FM500H battery, while the G9 can take 400 images on a single charge of its Panasonic DMW-BLF19 power pack. The power pack in the G9 can be charged via the USB port, which can be very convenient when travelling.

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 (USD)	Street Price
1.		Sony A77	143 mm	104 mm	81 mm	732 g	470	Y	Aug 2011	1,399	ebay.com
2.		Panasonic G9	137 mm	97 mm	92 mm	658 g	400	Y	Nov 2017	1,699	ebay.com
3.		Canon 6D	145 mm	111 mm	71 mm	770 g	1090	Y	Sep 2012	2,099	ebay.com
4.		Olympus E-M1 II	134 mm	91 mm	67 mm	574 g	440	Y	Sep 2016	1,999	ebay.com
5.		Panasonic G9 II	134 mm	102 mm	90 mm	658 g	390	Y	Sep 2023	1,899	amazon.com
6.		Panasonic G85	128 mm	89 mm	74 mm	505 g	330	Y	Sep 2016	899	ebay.com
7.		Panasonic GH5	139 mm	98 mm	87 mm	725 g	410	Y	Jan 2017	1,999	ebay.com
8.		Panasonic GH5 II	139 mm	98 mm	87 mm	727 g	400	Y	May 2021	1,699	amazon.com
9.		Pentax K-3	131 mm	100 mm	77 mm	800 g	560	Y	Oct 2013	1,299	ebay.com
10.		Sony A7 II	127 mm	96 mm	60 mm	599 g	350	Y	Nov 2014	1,999	ebay.com
11.		Sony A9	127 mm	96 mm	63 mm	673 g	650	Y	Apr 2017	4,499	ebay.com
12.		Sony A68	143 mm	104 mm	81 mm	610 g	540	n	Nov 2015	699	ebay.com
13.		Sony A77 II	143 mm	104 mm	81 mm	647 g	480	Y	May 2014	1,199	ebay.com
14.		Sony A99	147 mm	111 mm	78 mm	812 g	500	Y	Sep 2012	2,799	ebay.com
15.		Sony A6500	120 mm	67 mm	53 mm	453 g	350	Y	Oct 2016	1,399	ebay.com
16.		Sony A6600	120 mm	67 mm	69 mm	503 g	810	Y	Aug 2019	1,399	amazon.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 manufacturer’s suggested retail prices give an idea on the placement of the camera in the maker’s lineup and the broader market. The A77 was launched at a somewhat lower price (by 18 percent) than the G9, which makes it more attractive for photographers on a tight budget. 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 more expensive and lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the Sony A77 features an APS-C sensor and the Panasonic G9 a Four Thirds sensor. The sensor area in the G9 is 39 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.5 and 2.0. The sensor in the A77 has a native 3:2 aspect ratio, while the one in the G9 offers a 4:3 aspect.

With 24MP, the A77 offers a higher resolution than the G9 (20.2MP), but the A77 nevertheless has larger individual pixels (pixel pitch of 3.91μm versus 3.34μm for the G9) due to its larger sensor. However, the G9 is a much more recent model (by 6 years and 2 months) than the A77, 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 G9 has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

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 Panasonic G9 are 25.9 x 19.4 inches or 65.8 x 49.4 cm for good quality, 20.7 x 15.6 inches or 52.7 x 39.5 cm for very good quality, and 17.3 x 13 inches or 43.9 x 32.9 cm for excellent quality prints.

Unlike the A77, the G9 has the capacity to capture high quality composite images (80.6MP) 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 Sony Alpha SLT-A77 has a native sensitivity range from ISO 100 to ISO 16000, which can be extended to ISO 50-25600. The corresponding ISO settings for the Panasonic Lumix DC-G9 are ISO 200 to ISO 25600, with the possibility to increase the ISO range to 100-25600.

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 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.		Sony A77	APS-C	24.0	6000	4000	1080/60p	24.0	13.2	801	78
2.		Panasonic G9	Four Thirds	20.2	5184	3888	4K/60p	23.1	12.8	1138	74
3.		Canon 6D	Full Frame	20.0	5472	3648	1080/30p	23.8	12.1	2340	82
4.		Olympus E-M1 II	Four Thirds	20.2	5184	3888	4K/30p	23.7	12.8	1312	80
5.		Panasonic G9 II	Four Thirds	25.0	5776	4336	5.7K/60p	23.4	13.5	1710	78
6.		Panasonic G85	Four Thirds	15.8	4592	3448	4K/30p	22.8	12.5	656	71
7.		Panasonic GH5	Four Thirds	20.2	5184	3888	4K/60p	23.9	13.0	807	77
8.		Panasonic GH5 II	Four Thirds	20.2	5184	3888	4K/60p	23.7	13.1	1136	79
9.		Pentax K-3	APS-C	24.1	6016	4000	1080/60i	23.7	13.4	1216	80
10.		Sony A7 II	Full Frame	24.0	6000	4000	1080/60p	24.9	13.6	2449	90
11.		Sony A9	Full Frame	24.0	6000	4000	4K/30p	24.9	13.3	3517	92
12.		Sony A68	APS-C	24.0	6000	4000	1080/60i	24.1	13.5	701	79
13.		Sony A77 II	APS-C	24.0	6000	4000	1080/60p	24.4	13.4	1013	82
14.		Sony A99	Full Frame	24.0	6000	4000	1080/60p	25.0	14.0	1555	89
15.		Sony A6500	APS-C	24.0	6000	4000	4K/30p	24.5	13.7	1405	85
16.		Sony A6600	APS-C	24.0	6000	4000	4K/30p	23.8	13.4	1497	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 G9 provides a better video resolution than the A77. It can shoot movie footage at 4K/60p, while the Sony is limited to 1080/60p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. The two cameras under review are similar with respect to both having an electronic viewfinder. However, the one in the G9 offers a substantially higher resolution than the one in the A77 (3680k vs 2359k dots). The table below summarizes some of the other core capabilities of the Sony A77 and Panasonic G9 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.		Sony A77	2359	Y	3.0 / 921	full-flex	n	1/8000s	12.0/s	Y	Y
2.		Panasonic G9	3680	Y	3.0 / 1040	swivel	Y	1/8000s	20.0/s	n	Y
3.		Canon 6D	optical	Y	3.0 / 1040	fixed	n	1/4000s	4.5/s	n	n
4.		Olympus E-M1 II	2360	n	3.0 / 1037	swivel	Y	1/8000s	18.0/s	n	Y
5.		Panasonic G9 II	3680	n	3.0 / 1840	swivel	Y	1/8000s	10.0/s	n	Y
6.		Panasonic G85	2360	n	3.0 / 1040	swivel	Y	1/4000s	9.0/s	Y	Y
7.		Panasonic GH5	3680	n	3.2 / 1620	swivel	Y	1/8000s	12.0/s	n	Y
8.		Panasonic GH5 II	3680	n	3.0 / 1840	swivel	Y	1/8000s	12.0/s	n	Y
9.		Pentax K-3	optical	Y	3.2 / 1037	fixed	n	1/8000s	8.3/s	Y	Y
10.		Sony A7 II	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	Y
11.		Sony A9	3686	n	3.0 / 1440	tilting	Y	1/8000s	20.0/s	n	Y
12.		Sony A68	1440	Y	2.7 / 460	tilting	n	1/4000s	8.0/s	Y	Y
13.		Sony A77 II	2359	Y	3.0 / 1229	full-flex	n	1/8000s	12.0/s	Y	Y
14.		Sony A99	2359	Y	3.0 / 1229	full-flex	n	1/8000s	6.0/s	n	Y
15.		Sony A6500	2359	n	3.0 / 922	tilting	Y	1/4000s	11.0/s	Y	Y
16.		Sony A6600	2359	n	3.0 / 922	tilting	Y	1/4000s	11.0/s	n	Y
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One difference between the cameras concerns the presence of an on-board flash. The A77 has one, while the G9 does not. While the built-in flash of the A77 is not very powerful, it can at times be useful as a fill-in light.

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 G9 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 Panasonic G9 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 A77 writes its imaging data to SDXC or Memory Stick PRO Duo cards, while the G9 uses SDXC cards. The G9 features dual card slots, which can be very useful in case a memory card fails. In contrast, the A77 only has one slot. The G9 supports UHS-II cards (on both slots), while the A77 can use UHS-I 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 Sony Alpha SLT-A77 and Panasonic Lumix DC-G9 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.		Sony A77	Y	stereo / mono	Y	-	mini	2.0	-	-	-
2.		Panasonic G9	Y	stereo / mono	Y	Y	full	3.0	Y	-	Y
3.		Canon 6D	Y	mono / mono	Y	-	mini	2.0	Y	-	-
4.		Olympus E-M1 II	Y	stereo / mono	Y	Y	micro	3.0	Y	-	-
5.		Panasonic G9 II	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
6.		Panasonic G85	Y	stereo / mono	Y	-	micro	2.0	Y	-	-
7.		Panasonic GH5	Y	stereo / mono	Y	Y	full	3.1	Y	-	Y
8.		Panasonic GH5 II	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
9.		Pentax K-3	Y	mono / mono	Y	Y	mini	3.0	-	-	-
10.		Sony A7 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
11.		Sony A9	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	Y
12.		Sony A68	Y	stereo / mono	Y	-	micro	2.0	-	-	-
13.		Sony A77 II	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
14.		Sony A99	Y	stereo / mono	Y	Y	mini	2.0	-	-	-
15.		Sony A6500	Y	stereo / mono	Y	-	micro	2.0	Y	Y	-
16.		Sony A6600	Y	stereo / mono	Y	Y	YES	2.0	Y	Y	Y

It is notable that the G9 offers wifi support, which can be a very convenient means to transfer image data to an off-camera location. In contrast, the A77 does not provide wifi capability.

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 A77 has an internal geolocalization sensor and can record GPS coordinates in its EXIF data.

Both the A77 and the G9 have been discontinued, but can regularly be found used on ebay. The A77 was replaced by the Sony A77 II, while the G9 was followed by the Panasonic G9 II. Further information on the features and operation of the A77 and G9 can be found, respectively, in the Sony A77 Manual (free pdf) or the online Panasonic G9 Manual.

Review summary

So what conclusions can be drawn? Which of the two cameras – the Sony A77 or the Panasonic G9 – 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 Sony Alpha SLT-A77:

• More detail: Offers more megapixels (24 vs 20.2MP) with a 11% higher linear resolution.
• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• Longer lasting: Can take more shots (470 versus 400) on a single battery charge.
• Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
• Easier geotagging: Features an internal GPS sensor to log localization data.
• More affordable: Was introduced into a lower priced segment (18 percent cheaper at launch).
• More heavily discounted: Has been available for much longer (launched in August 2011).

Advantages of the Panasonic Lumix DC-G9:

• 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 video: Provides higher definition movie capture (4K/60p vs 1080/60p).
• Better sound control: Has a headphone port that enables audio monitoring while recording.
• More detailed viewfinder: Has higher resolution electronic viewfinder (3680k vs 2359k dots).
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.83x vs 0.73x).
• More detailed LCD: Has a higher resolution rear screen (1040k vs 921k dots).
• Fewer buttons to press: Has a touchscreen to facilitate handling and shooting adjustments.
• Faster burst: Shoots at higher frequency (20 vs 12 flaps/sec) to capture the decisive moment.
• Less disturbing: Has an electronic shutter option for completely silent shooting.
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• More compact: Is smaller (137x97mm vs 143x104mm) and will fit more readily into a bag.
• Easier travel charging: Can be conveniently charged via its USB port.
• More legacy lens friendly: Can use many non-native lenses via adapters.
• Faster data transfer: Supports a more advanced USB protocol (3.0 vs 2.0).
• Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
• Easier wireless transfer: Supports Bluetooth for image sharing without cables.
• Greater peace of mind: Features a second card slot as a backup in case of memory card failure.
• Faster buffer clearing: Supports a more advanced SD data transfer standard (UHS-II vs UHS-I).
• More modern: Reflects 6 years and 2 months of technical progress since the A77 launch.

If the count of relative strengths (bullet points above) is taken as a measure, the G9 is the clear winner of the contest (21 : 7 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 Sony A77 and the Panasonic G9 place the cameras among the top in their class? Find out in the latest Best DSLR Camera and Best Mirrorless Interchangeable Lens 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 A77 or the G9. 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 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.		Sony A77	5/5	91/100	..	81/100	..	5/5	Aug 2011	1,399	ebay.com
2.		Panasonic G9	..	+ +	5/5	85/100	5/5	5/5	Nov 2017	1,699	ebay.com
3.		Canon 6D	5/5	+ +	..	83/100	4.5/5	4.5/5	Sep 2012	2,099	ebay.com
4.		Olympus E-M1 II	5/5	+ +	5/5	85/100	4.5/5	4.5/5	Sep 2016	1,999	ebay.com
5.		Panasonic G9 II	5/5	..	4.5/5	87/100	..	4.5/5	Sep 2023	1,899	amazon.com
6.		Panasonic G85	..	+ +	..	84/100	5/5	4.5/5	Sep 2016	899	ebay.com
7.		Panasonic GH5	4.5/5	+ +	..	85/100	4.5/5	5/5	Jan 2017	1,999	ebay.com
8.		Panasonic GH5 II	4.5/5	..	4.5/5	85/100	4.5/5	5/5	May 2021	1,699	amazon.com
9.		Pentax K-3	4/5	..	..	83/100	5/5	5/5	Oct 2013	1,299	ebay.com
10.		Sony A7 II	5/5	+	4/5	82/100	4.5/5	5/5	Nov 2014	1,999	ebay.com
11.		Sony A9	5/5	+ +	4.8/5	89/100	5/5	5/5	Apr 2017	4,499	ebay.com
12.		Sony A68	3/5	..	..	..	4/5	4/5	Nov 2015	699	ebay.com
13.		Sony A77 II	4/5	..	..	80/100	4.5/5	5/5	May 2014	1,199	ebay.com
14.		Sony A99	5/5	..	..	84/100	4.5/5	4.5/5	Sep 2012	2,799	ebay.com
15.		Sony A6500	5/5	+ +	3.5/5	85/100	4.5/5	4.5/5	Oct 2016	1,399	ebay.com
16.		Sony A6600	4/5	+	4/5	83/100	4.5/5	4/5	Aug 2019	1,399	amazon.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.

Check A77 offers at
ebay.com
Check G9 offers at
ebay.com

Other camera comparisons

Did this review help to inform your camera decision process? In case you are interested in seeing how other cameras pair up, just make your choice using the following search menu. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.

~

Check A77 offers at
ebay.com
Check G9 offers at
ebay.com

Did you notice an error on this page? If so, please get in touch, so that we can correct the information.