Panasonic GX9 vs Sony A5100

The Panasonic Lumix DC-GX9 and the Sony Alpha A5100 are two digital cameras that were announced, respectively, in February 2018 and August 2014. Both the GX9 and the A5100 are mirrorless interchangeable lens cameras that are based on a Four Thirds (GX9) and an APS-C (A5100) sensor. The Panasonic has a resolution of 20.2 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

Panasonic GX9		Sony A5100
Mirrorless system camera		Mirrorless system camera
Micro Four Thirds lenses		Sony E mount lenses
20.2 MP – Four Thirds sensor		24 MP – APS-C sensor
4K/30p Video		1080/60p Video
ISO 200-25,600		ISO 100-25,600
Electronic viewfinder (2760k dots)		No viewfinder, LCD framing
3.0" LCD – 1240k dots		3.0" LCD – 922k dots
Tilting touchscreen		Tilting touchscreen
9 shutter flaps per second		6 shutter flaps per second
In-body stabilization		Lens stabilization only
260 shots per battery charge		400 shots per battery charge
124 x 72 x 47 mm, 407 g		110 x 63 x 36 mm, 283 g

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Check A5100 offers at
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Going beyond this snapshot of core features and characteristics, what are the differences between the Panasonic Lumix DC-GX9 and the Sony Alpha A5100? 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 Panasonic GX9 and the Sony A5100 are illustrated 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 width, height and depth dimensions are rounded to the nearest millimeter.

The GX9 can be obtained in two different colors (black, silver), while the A5100 is also available in two color-versions, but different ones (black, white).

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Sony A5100 is notably smaller (22 percent) than the Panasonic GX9. Moreover, the A5100 is markedly lighter (30 percent) than the GX9. In this context, it is worth noting that neither the GX9 nor the A5100 are weather-sealed.

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. A larger imaging sensor will tend to go along with bigger and heavier lenses, although exceptions exist. You can compare the optics available for the two cameras in the Micro Four Thirds Lens Catalog (GX9) and the Sony E-Mount Lens Catalog (A5100). Mirrorless cameras, such as the two under consideration, have the additional advantage of having a short flange to focal plane distance, which makes it possible to mount many lenses from other systems onto the camera via adapters.

Concerning battery life, the GX9 gets 260 shots out of its Panasonic DMW-BLG10 battery, while the A5100 can take 400 images on a single charge of its Sony NP-FW50 power pack. The battery packs of both cameras can be charged via USB, which can be very convenient when travelling.

The table below summarizes the key physical specs of the two cameras alongside a broader set of comparators. 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.		Panasonic GX9	124 mm	72 mm	47 mm	407 g	260	n	Feb 2018	849	ebay.com
2.		Sony A5100	110 mm	63 mm	36 mm	283 g	400	n	Aug 2014	549	ebay.com
3.		Olympus E-M10 II	120 mm	83 mm	47 mm	390 g	320	n	Aug 2015	649	ebay.com
4.		Olympus E-M10 III	122 mm	84 mm	50 mm	410 g	330	n	Aug 2017	649	ebay.com
5.		Olympus E-M10 IV	122 mm	84 mm	49 mm	383 g	360	n	Aug 2020	699	amazon.com
6.		Olympus E-P7	118 mm	69 mm	38 mm	337 g	360	n	Jun 2021	799	amazon.com
7.		Panasonic G95	130 mm	94 mm	77 mm	536 g	290	Y	Apr 2019	999	ebay.com
8.		Panasonic GX7	123 mm	71 mm	55 mm	402 g	350	n	Aug 2013	999	ebay.com
9.		Panasonic GX8	133 mm	78 mm	63 mm	487 g	330	Y	Jul 2015	1,199	ebay.com
10.		Panasonic GX85	122 mm	71 mm	44 mm	426 g	290	n	Apr 2016	799	amazon.com
11.		Panasonic LX100 II	115 mm	66 mm	65 mm	392 g	300	n	Aug 2018	999	ebay.com
12.		Panasonic ZS200	111 mm	65 mm	45 mm	340 g	370	n	Feb 2018	799	amazon.com
13.		Sony A3000	128 mm	91 mm	85 mm	411 g	470	n	Aug 2013	329	ebay.com
14.		Sony A5000	110 mm	63 mm	36 mm	269 g	420	n	Jan 2014	449	ebay.com
15.		Sony A6000	120 mm	67 mm	45 mm	344 g	360	n	Feb 2014	599	ebay.com
16.		Sony NEX-3	117 mm	62 mm	33 mm	297 g	330	n	May 2010	599	ebay.com
17.		Sony NEX-3N	110 mm	62 mm	35 mm	269 g	480	n	Feb 2013	499	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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Any camera decision will naturally be influenced heavily by the price. 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 A5100 was launched at a markedly lower price (by 35 percent) than the GX9, which puts it into a different market segment. 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 imaging sensor is at the core of digital cameras and its size is one of the main determining factors 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 Panasonic GX9 features a Four Thirds sensor and the Sony A5100 an APS-C sensor. The sensor area in the A5100 is 63 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 2.0 and 1.5. The sensor in the GX9 has a native 4:3 aspect ratio, while the one in the A5100 offers a 3:2 aspect.

With 24MP, the A5100 offers a higher resolution than the GX9 (20.2MP), but the A5100 nevertheless has larger individual pixels (pixel pitch of 3.91μm versus 3.34μm for the GX9) due to its larger sensor. However, the GX9 is a much more recent model (by 3 years and 5 months) than the A5100, and its sensor will have benefitted from technological advances during this time that enhance the light gathering capacity of its pixel-units. Coming back to sensor resolution, it should be mentioned that the GX9 has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

The resolution advantage of the Sony A5100 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A5100 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 GX9 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.

The A5100 has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.

The Panasonic Lumix DC-GX9 has a native sensitivity range from ISO 200 to ISO 25600, which can be extended to ISO 100-25600. The corresponding ISO settings for the Sony Alpha A5100 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.

Consistent information on actual sensor performance is available from DXO Mark for many cameras. 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.		Panasonic GX9	Four Thirds	20.2	5184	3888	4K/30p	23.1	12.8	1163	74
2.		Sony A5100	APS-C	24.0	6000	4000	1080/60p	23.8	12.7	1347	80
3.		Olympus E-M10 II	Four Thirds	15.9	4608	3456	1080/60p	23.1	12.5	842	73
4.		Olympus E-M10 III	Four Thirds	15.9	4608	3456	4K/30p	23.1	12.8	1120	74
5.		Olympus E-M10 IV	Four Thirds	20.2	5184	3888	4K/30p	23.3	13.2	1402	76
6.		Olympus E-P7	Four Thirds	20.2	5184	3888	4K/30p	23.4	13.3	1494	77
7.		Panasonic G95	Four Thirds	20.2	5184	3888	4K/30p	23.2	13.0	1273	75
8.		Panasonic GX7	Four Thirds	15.8	4592	3448	1080/60p	22.6	12.2	718	70
9.		Panasonic GX8	Four Thirds	20.2	5184	3888	4K/30p	23.5	12.6	806	75
10.		Panasonic GX85	Four Thirds	15.8	4592	3448	4K/30p	22.9	12.6	662	71
11.		Panasonic LX100 II	Four Thirds	16.8	4736	3552	4K/30p	22.8	12.7	979	72
12.		Panasonic ZS200	1-inch	20.0	5472	3648	4K/30p	22.0	12.2	449	64
13.		Sony A3000	APS-C	19.8	5456	3632	1080/60i	23.7	12.8	1068	78
14.		Sony A5000	APS-C	19.8	5456	3632	1080/60i	23.8	13.0	1089	79
15.		Sony A6000	APS-C	24.0	6000	4000	1080/60p	24.1	13.1	1347	82
16.		Sony NEX-3	APS-C	14.0	4592	3056	720/30p	22.1	12.0	830	68
17.		Sony NEX-3N	APS-C	16.0	4912	3264	1080/60i	22.8	12.5	1067	74
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 are equipped with sensors that have a sufficiently high read-out speed for moving images, but the GX9 provides a higher video resolution than the A5100. It can shoot video footage at 4K/30p, 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. For example, the GX9 has an electronic viewfinder (2760k dots), which can be very helpful when shooting in bright sunlight. In contrast, the A5100 relies on live view and the rear LCD for framing. The adjacent table lists some of the other core features of the Panasonic GX9 and Sony A5100 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.		Panasonic GX9	2760	n	3.0 / 1240	tilting	Y	1/4000s	9.0/s	Y	Y
2.		Sony A5100	none	n	3.0 / 922	tilting	Y	1/4000s	6.0/s	Y	n
3.		Olympus E-M10 II	2360	n	3.0 / 1040	tilting	Y	1/4000s	8.0/s	Y	Y
4.		Olympus E-M10 III	2360	n	3.0 / 1040	tilting	Y	1/4000s	8.6/s	Y	Y
5.		Olympus E-M10 IV	2360	n	3.0 / 1040	tilting	Y	1/4000s	15.0/s	Y	Y
6.		Olympus E-P7	none	n	3.0 / 1040	tilting	Y	1/4000s	8.7/s	Y	Y
7.		Panasonic G95	2360	n	3.0 / 1240	swivel	Y	1/4000s	9.0/s	Y	Y
8.		Panasonic GX7	2760	n	3.0 / 1040	tilting	Y	1/8000s	5.0/s	Y	Y
9.		Panasonic GX8	2360	n	3.0 / 1040	swivel	Y	1/8000s	10.0/s	n	Y
10.		Panasonic GX85	2765	n	3.0 / 1040	tilting	Y	1/4000s	8.0/s	Y	Y
11.		Panasonic LX100 II	2764	n	3.0 / 1240	fixed	Y	1/4000s	11.0/s	n	Y
12.		Panasonic ZS200	2330	n	3.0 / 1240	fixed	Y	1/2000s	10.0/s	Y	Y
13.		Sony A3000	202	n	3.0 / 230	fixed	n	1/4000s	2.5/s	Y	n
14.		Sony A5000	none	n	3.0 / 461	tilting	n	1/4000s	3.5/s	Y	n
15.		Sony A6000	1440	n	3.0 / 922	tilting	n	1/4000s	11.0/s	Y	n
16.		Sony NEX-3	optional	n	3.0 / 920	tilting	n	1/4000s	7.0/s	n	n
17.		Sony NEX-3N	optional	n	3.0 / 460	tilting	n	1/4000s	4.0/s	Y	n
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One feature that differentiates the GX9 and the A5100 is in-body image stabilization (IBIS). The GX9 reduces the risk of handshake-induced blur with all attached lenses, while the A5100 offers no blur reduction with lenses that themselves do not provide optical image stabilization.

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 GX9 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 GX9 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 GX9 writes its imaging data to SDXC cards, while the A5100 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 Panasonic Lumix DC-GX9 and Sony Alpha A5100 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.		Panasonic GX9	Y	stereo / mono	-	-	micro	2.0	Y	-	Y
2.		Sony A5100	-	stereo / mono	-	-	micro	2.0	Y	Y	-
3.		Olympus E-M10 II	Y	stereo / mono	-	-	micro	2.0	Y	-	-
4.		Olympus E-M10 III	Y	stereo / mono	-	-	micro	2.0	Y	-	-
5.		Olympus E-M10 IV	Y	stereo / mono	-	-	micro	2.0	Y	-	Y
6.		Olympus E-P7	Y	stereo / mono	-	-	micro	2.0	Y	-	Y
7.		Panasonic G95	Y	stereo / mono	Y	Y	micro	2.0	Y	-	Y
8.		Panasonic GX7	Y	stereo / mono	-	-	mini	2.0	Y	Y	-
9.		Panasonic GX8	Y	stereo / mono	Y	-	micro	2.0	Y	Y	-
10.		Panasonic GX85	Y	stereo / mono	-	-	micro	2.0	Y	-	-
11.		Panasonic LX100 II	Y	stereo / mono	-	-	micro	2.0	Y	-	Y
12.		Panasonic ZS200	-	stereo / mono	-	-	micro	2.0	Y	-	Y
13.		Sony A3000	Y	stereo / mono	-	-	mini	2.0	-	-	-
14.		Sony A5000	-	stereo / mono	-	-	micro	2.0	Y	Y	-
15.		Sony A6000	Y	stereo / mono	-	-	micro	2.0	Y	Y	-
16.		Sony NEX-3	Y	stereo / mono	-	-	mini	2.0	-	-	-
17.		Sony NEX-3N	-	stereo / mono	-	-	micro	2.0	-	-	-

It is notable that the GX9 has a hotshoe, while the A5100 does not. This socket makes it possible to easily attach optional accessories, such as an external flash gun.

Both the GX9 and the A5100 have been discontinued, but can regularly be found used on ebay. Neither of the two has a direct successor, so they represent the end of the respective camera lines from Panasonic and Sony. Further information on the features and operation of the GX9 and A5100 can be found, respectively, in the Panasonic GX9 Manual (free pdf) or the online Sony A5100 Manual.

Review summary

So what conclusions can be drawn? Is the Panasonic GX9 better than the Sony A5100 or vice versa? The listing below highlights the relative strengths of the two models.

Advantages of the Panasonic Lumix DC-GX9:

• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• Better video: Provides higher definition movie capture (4K/30p vs 1080/60p).
• Easier framing: Has an electronic viewfinder for image composition and settings control.
• More detailed LCD: Has a higher resolution rear screen (1240k vs 922k dots).
• Faster burst: Shoots at higher frequency (9 vs 6 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.
• Sharper images: Has hand-shake reducing image stabilization built-in.
• Better lighting: Features a hotshoe and can thus hold and trigger an external flash gun.
• Easier wireless transfer: Supports Bluetooth for image sharing without cables.
• More modern: Reflects 3 years and 5 months of technical progress since the A5100 launch.

Arguments in favor of the Sony Alpha A5100:

• More detail: Has more megapixels (24 vs 20.2MP), which boosts linear resolution by 11%.
• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
• More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
• More compact: Is smaller (110x63mm vs 124x72mm) and will fit more readily into a bag.
• Less heavy: Has a lower weight (by 124g or 30 percent) and is thus easier to take along.
• Longer lasting: Gets more shots (400 versus 260) out of a single battery charge.
• Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
• More affordable: Was introduced into a lower priced category (35 percent cheaper at launch).
• More heavily discounted: Has been around for much longer (launched in August 2014).

If the number of relative strengths (bullet points above) is taken as a guide, the GX9 comes out slightly ahead of the A5100 (11 : 10 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 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 Panasonic GX9 and the Sony A5100 place the cameras among the top in their class? Find out in the latest Best Mirrorless Interchangeable Lens Camera listing 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 GX9 and the A5100 in practical situations. 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 why expert reviews 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.		Panasonic GX9	4/5	+	4/5	84/100	4.5/5	4.5/5	Feb 2018	849	ebay.com
2.		Sony A5100	4.5/5	+	..	..	4.5/5	5/5	Aug 2014	549	ebay.com
3.		Olympus E-M10 II	4.5/5	+ +	..	80/100	5/5	5/5	Aug 2015	649	ebay.com
4.		Olympus E-M10 III	..	+	5/5	80/100	4.5/5	4.5/5	Aug 2017	649	ebay.com
5.		Olympus E-M10 IV	4.5/5	..	5/5	81/100	4.5/5	4.5/5	Aug 2020	699	amazon.com
6.		Olympus E-P7	4/5	..	4.5/5	..	..	4.5/5	Jun 2021	799	amazon.com
7.		Panasonic G95	4.5/5	+	4.5/5	83/100	4.5/5	4.5/5	Apr 2019	999	ebay.com
8.		Panasonic GX7	4/5	+	..	79/100	5/5	5/5	Aug 2013	999	ebay.com
9.		Panasonic GX8	5/5	+	..	82/100	4.5/5	4.5/5	Jul 2015	1,199	ebay.com
10.		Panasonic GX85	4.5/5	+ +	..	82/100	5/5	5/5	Apr 2016	799	amazon.com
11.		Panasonic LX100 II	4.5/5	+	4.2/5	82/100	4.5/5	4.5/5	Aug 2018	999	ebay.com
12.		Panasonic ZS200	..	+ +	4.5/5	81/100	4.5/5	4.5/5	Feb 2018	799	amazon.com
13.		Sony A3000	3/5	+	..	..	4/5	4/5	Aug 2013	329	ebay.com
14.		Sony A5000	3/5	+	..	..	4.5/5	4.5/5	Jan 2014	449	ebay.com
15.		Sony A6000	5/5	+	4.5/5	80/100	4.5/5	5/5	Feb 2014	599	ebay.com
16.		Sony NEX-3	..	..	..	70/100	4.5/5	4/5	May 2010	599	ebay.com
17.		Sony NEX-3N	3/5	..	..	..	4.5/5	4.5/5	Feb 2013	499	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The review scores listed above should be treated with care, though. The ratings were established in reference to similarly priced cameras that were available in the market at the time of the review. 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

Did this review help to inform your camera decision process? If you would like to see a different side-by-side camera review, just use the search menu below. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.

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