Panasonic GM1 vs Sony A58

The Panasonic Lumix DMC-GM1 and the Sony Alpha SLT-A58 are two digital cameras that were officially introduced, respectively, in October 2013 and February 2013. The GM1 is a mirrorless interchangeable lens camera, while the A58 is a DSLR. The cameras are based on a Four Thirds (GM1) and an APS-C (A58) sensor. The Panasonic has a resolution of 15.8 megapixels, whereas the Sony provides 19.8 MP.

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

Headline Specifications

Panasonic GM1		Sony A58
Mirrorless system camera		Digital single lens reflex
Micro Four Thirds lenses		Sony A mount lenses
15.8 MP – Four Thirds sensor		19.8 MP – APS-C sensor
1080/60i Video		1080/60i Video
ISO 200-25,600		ISO 100-16,000 (100 - 25,600)
No viewfinder, LCD framing		Electronic viewfinder (1440k dots)
3.0" LCD – 1036k dots		2.7" LCD – 460k dots
Fixed touchscreen		Tilting screen (no touchscreen)
5 shutter flaps per second		5 shutter flaps per second
Lens stabilization only		In-body stabilization
230 shots per battery charge		690 shots per battery charge
99 x 55 x 30 mm, 204 g		129 x 95 x 78 mm, 492 g

Check GM1 offers at
ebay.com
Check A58 offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Panasonic Lumix DMC-GM1 and the Sony Alpha SLT-A58? 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 GM1 and the Sony A58 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 GM1 can be obtained in three different colors (black, silver, red), while the A58 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 A58 is considerably larger (125 percent) than the Panasonic GM1. Moreover, the A58 is substantially heavier (141 percent) than the GM1. In this context, it is worth noting that neither the GM1 nor the A58 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. 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 GM1 gets 230 shots out of its Panasonic DMW-BLH7 battery, while the A58 can take 690 images on a single charge of its Sony NP-FM500H 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.		Panasonic GM1	99 mm	55 mm	30 mm	204 g	230	n	Oct 2013	749	ebay.com
2.		Sony A58	129 mm	95 mm	78 mm	492 g	690	n	Feb 2013	599	ebay.com
3.		Nikon D3200	125 mm	96 mm	77 mm	505 g	540	n	Apr 2012	599	ebay.com
4.		Panasonic G3	115 mm	84 mm	47 mm	336 g	270	n	May 2011	599	ebay.com
5.		Panasonic G5	120 mm	83 mm	71 mm	396 g	320	n	Jul 2012	599	ebay.com
6.		Panasonic G6	122 mm	85 mm	71 mm	390 g	340	n	Apr 2013	599	ebay.com
7.		Panasonic GH2	124 mm	90 mm	76 mm	442 g	330	n	Sep 2010	899	ebay.com
8.		Panasonic GH3	133 mm	93 mm	82 mm	550 g	540	Y	Sep 2012	1,299	ebay.com
9.		Panasonic GM5	99 mm	60 mm	36 mm	211 g	220	n	Sep 2014	749	ebay.com
10.		Panasonic GX1	116 mm	68 mm	39 mm	318 g	320	n	Nov 2011	699	ebay.com
11.		Panasonic GX7	123 mm	71 mm	55 mm	402 g	350	n	Aug 2013	999	ebay.com
12.		Panasonic LX100	115 mm	66 mm	55 mm	393 g	300	n	Sep 2014	899	ebay.com
13.		Ricoh GR	117 mm	61 mm	35 mm	245 g	290	n	Apr 2013	799	ebay.com
14.		Sony A68	143 mm	104 mm	81 mm	610 g	540	n	Nov 2015	699	ebay.com
15.		Sony A77 II	143 mm	104 mm	81 mm	647 g	480	Y	May 2014	1,199	ebay.com
16.		Sony A5100	110 mm	63 mm	36 mm	283 g	400	n	Aug 2014	549	ebay.com
17.		Sony A6000	120 mm	67 mm	45 mm	344 g	360	n	Feb 2014	599	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. The A58 was launched at a somewhat lower price (by 20 percent) than the GM1, 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 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. Moreover, a large sensor camera will give the photographer more control over depth-of-field in the image and, thus, the ability to better isolate a subject from the 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 Panasonic GM1 features a Four Thirds sensor and the Sony A58 an APS-C sensor. The sensor area in the A58 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 GM1 has a native 4:3 aspect ratio, while the one in the A58 offers a 3:2 aspect.

With 19.8MP, the A58 offers a higher resolution than the GM1 (15.8MP), but the A58 nevertheless has larger individual pixels (pixel pitch of 4.31μm versus 3.77μm for the GM1) due to its larger sensor. However, the GM1 is a somewhat more recent model (by 7 months) than the A58, and its sensor might have benefitted from technological advances during this time that enhance the light gathering capacity of its pixel-units.

The resolution advantage of the Sony A58 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A58 for good quality output (200 dots per inch) amounts to 27.3 x 18.2 inches or 69.3 x 46.1 cm, for very good quality (250 dpi) 21.8 x 14.5 inches or 55.4 x 36.9 cm, and for excellent quality (300 dpi) 18.2 x 12.1 inches or 46.2 x 30.8 cm. The corresponding values for the Panasonic GM1 are 23 x 17.2 inches or 58.3 x 43.8 cm for good quality, 18.4 x 13.8 inches or 46.7 x 35 cm for very good quality, and 15.3 x 11.5 inches or 38.9 x 29.2 cm for excellent quality prints.

The Panasonic Lumix DMC-GM1 has a native sensitivity range from ISO 200 to ISO 25600, which can be extended to ISO 125-25600. The corresponding ISO settings for the Sony Alpha SLT-A58 are ISO 100 to ISO 16000, 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.

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"). Of the two cameras under consideration, the A58 has a markedly higher DXO score than the GM1 (overall score 8 points higher), which will translate into better image quality. The advantage is based on 1 bits higher color depth, 0.8 EV in additional dynamic range, and 0.2 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.		Panasonic GM1	Four Thirds	15.8	4592	3448	1080/60i	22.3	11.7	660	66
2.		Sony A58	APS-C	19.8	5456	3632	1080/60i	23.3	12.5	753	74
3.		Nikon D3200	APS-C	24.1	6016	4000	1080/30p	24.1	13.2	1131	81
4.		Panasonic G3	Four Thirds	15.8	4592	3448	1080/60i	21.0	10.6	667	56
5.		Panasonic G5	Four Thirds	15.9	4608	3456	1080/60p	21.4	11.6	618	61
6.		Panasonic G6	Four Thirds	15.9	4608	3456	1080/60p	21.3	11.5	639	61
7.		Panasonic GH2	Four Thirds	15.9	4608	3456	1080/60i	21.2	11.3	655	60
8.		Panasonic GH3	Four Thirds	15.9	4608	3456	1080/60p	22.7	12.4	812	71
9.		Panasonic GM5	Four Thirds	15.8	4592	3448	1080/60p	22.1	11.7	721	66
10.		Panasonic GX1	Four Thirds	15.8	4592	3448	1080/60p	20.8	10.6	703	55
11.		Panasonic GX7	Four Thirds	15.8	4592	3448	1080/60p	22.6	12.2	718	70
12.		Panasonic LX100	Four Thirds	12.7	4112	3088	4K/30p	22.3	12.5	553	67
13.		Ricoh GR	APS-C	16.1	4928	3264	1080/30p	23.6	13.5	972	78
14.		Sony A68	APS-C	24.0	6000	4000	1080/60i	24.1	13.5	701	79
15.		Sony A77 II	APS-C	24.0	6000	4000	1080/60p	24.4	13.4	1013	82
16.		Sony A5100	APS-C	24.0	6000	4000	1080/60p	23.8	12.7	1347	80
17.		Sony A6000	APS-C	24.0	6000	4000	1080/60p	24.1	13.1	1347	82

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, and both provide the same movie specifications (1080/60i).

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. For example, the A58 has an electronic viewfinder (1440k dots), which can be very helpful when shooting in bright sunlight. In contrast, the GM1 relies on live view and the rear LCD for framing. The adjacent table lists some of the other core features of the Panasonic GM1 and Sony A58 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 GM1	none	n	3.0 / 1036	fixed	Y	1/500s	5.0/s	Y	n
2.		Sony A58	1440	n	2.7 / 460	tilting	n	1/4000s	5.0/s	Y	Y
3.		Nikon D3200	optical	n	3.0 / 921	fixed	n	1/4000s	4.0/s	Y	n
4.		Panasonic G3	1440	n	3.0 / 460	swivel	Y	1/4000s	4.0/s	Y	n
5.		Panasonic G5	1440	n	3.0 / 920	swivel	Y	1/4000s	6.0/s	Y	n
6.		Panasonic G6	1440	n	3.0 / 1036	swivel	Y	1/4000s	7.0/s	Y	n
7.		Panasonic GH2	1534	n	3.0 / 460	swivel	n	1/4000s	3.0/s	Y	n
8.		Panasonic GH3	1746	n	3.0 / 614	swivel	Y	1/4000s	6.0/s	Y	n
9.		Panasonic GM5	1166	n	3.0 / 921	fixed	Y	1/500s	5.8/s	n	n
10.		Panasonic GX1	optional	n	3.0 / 460	fixed	Y	1/4000s	4.2/s	Y	n
11.		Panasonic GX7	2760	n	3.0 / 1040	tilting	Y	1/8000s	5.0/s	Y	Y
12.		Panasonic LX100	2764	n	3.0 / 921	fixed	n	1/4000s	11.0/s	n	Y
13.		Ricoh GR	optional	n	3.0 / 1230	fixed	n	1/4000s	4.0/s	Y	n
14.		Sony A68	1440	Y	2.7 / 460	tilting	n	1/4000s	8.0/s	Y	Y
15.		Sony A77 II	2359	Y	3.0 / 1229	full-flex	n	1/8000s	12.0/s	Y	Y
16.		Sony A5100	none	n	3.0 / 922	tilting	Y	1/4000s	6.0/s	Y	n
17.		Sony A6000	1440	n	3.0 / 922	tilting	n	1/4000s	11.0/s	Y	n
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 GM1 has a touchscreen, while the A58 has a conventional panel. Touch control can be particularly helpful, for example, for setting the focus point.

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 GM1 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 GM1 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 GM1 writes its imaging data to SDXC cards, while the A58 uses SDXC or Memory Stick PRO Duo cards. The GM1 supports UHS-I cards (Ultra High Speed data transfer of up to 104 MB/s), while the A58 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 Panasonic Lumix DMC-GM1 and Sony Alpha SLT-A58 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 GM1	-	stereo / mono	-	-	micro	2.0	Y	-	-
2.		Sony A58	Y	stereo / mono	Y	-	mini	2.0	-	-	-
3.		Nikon D3200	Y	mono / mono	Y	-	mini	2.0	-	-	-
4.		Panasonic G3	Y	stereo / mono	-	-	mini	2.0	-	-	-
5.		Panasonic G5	Y	stereo / mono	-	-	mini	2.0	-	-	-
6.		Panasonic G6	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
7.		Panasonic GH2	Y	stereo / mono	Y	-	mini	2.0	-	-	-
8.		Panasonic GH3	Y	stereo / mono	Y	Y	mini	2.0	Y	-	-
9.		Panasonic GM5	Y	stereo / mono	-	-	micro	2.0	Y	-	-
10.		Panasonic GX1	Y	stereo / mono	-	-	mini	2.0	-	-	-
11.		Panasonic GX7	Y	stereo / mono	-	-	mini	2.0	Y	Y	-
12.		Panasonic LX100	Y	stereo / mono	-	-	micro	2.0	Y	Y	-
13.		Ricoh GR	Y	mono / mono	-	-	micro	2.0	-	-	-
14.		Sony A68	Y	stereo / mono	Y	-	micro	2.0	-	-	-
15.		Sony A77 II	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
16.		Sony A5100	-	stereo / mono	-	-	micro	2.0	Y	Y	-
17.		Sony A6000	Y	stereo / mono	-	-	micro	2.0	Y	Y	-

It is notable that the GM1 offers wifi support, while the A58 does not. Wifi can be a very convenient means to transfer image data to an off-camera location.

Both the GM1 and the A58 have been discontinued, but can regularly be found used on ebay. The A58 was replaced by the Sony A68, while the GM1 was followed by the Panasonic GM5. Further information on the features and operation of the GM1 and A58 can be found, respectively, in the Panasonic GM1 Manual (free pdf) or the online Sony A58 Manual.

Review summary

So how do things add up? Which of the two cameras – the Panasonic GM1 or the Sony A58 – 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.

Arguments in favor of the Panasonic Lumix DMC-GM1:

• Larger screen: Has a bigger rear LCD (3.0" vs 2.7") for image review and settings control.
• More detailed LCD: Has a higher resolution rear screen (1036k vs 460k dots).
• Fewer buttons to press: Is equipped with a touch-sensitive rear screen to facilitate handling.
• 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 (99x55mm vs 129x95mm) and thus needs less room in the bag.
• Less heavy: Is lighter (by 288g or 59 percent) and hence easier to carry around.
• More legacy lens friendly: Can take a broad range of non-native lenses via adapters.
• Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
• Faster buffer clearing: Has an SD card interface that supports the UHS-I standard.
• More modern: Is somewhat more recent (announced 7 months after the A58).

Advantages of the Sony Alpha SLT-A58:

• More detail: Has more megapixels (19.8 vs 15.8MP), which boosts linear resolution by 14%.
• Better image quality: Scores markedly higher (8 points) in the DXO overall evaluation.
• More dynamic range: Captures a broader range of light and dark details (0.8 EV of extra DR).
• 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.
• More flexible LCD: Has a tilting screen for odd-angle shots in landscape orientation.
• Faster shutter: Has higher mechanical shutter speed (1/4000s vs 1/500s) to freeze action.
• Longer lasting: Gets more shots (690 versus 230) out of a single battery charge.
• Sharper images: Has stabilization technology built-in to reduce the impact of hand-shake.
• Better lighting: Features a hotshoe and can thus hold and trigger an external flash gun.
• More affordable: Was released into a lower priced segment (20 percent cheaper at launch).
• More heavily discounted: Has been on the market for longer (launched in February 2013).

If the count of individual advantages (bullet points above) is taken as a guide, the A58 comes out slightly ahead of the GM1 (12 : 11 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 GM1 and the Sony A58 place the cameras among the top in their class? Find out in the latest Best Mirrorless Interchangeable Lens 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 says little about, for example, the shooting experience and imaging performance of the GM1 and the A58 in practical situations. 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 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 GM1	3/5	+	..	78/100	5/5	4.5/5	Oct 2013	749	ebay.com
2.		Sony A58	3/5	..	..	..	4.5/5	4.5/5	Feb 2013	599	ebay.com
3.		Nikon D3200	5/5	+ +	..	73/100	4.5/5	4.5/5	Apr 2012	599	ebay.com
4.		Panasonic G3	3/5	+ +	..	75/100	4.5/5	5/5	May 2011	599	ebay.com
5.		Panasonic G5	3/5	+ +	..	..	4.5/5	4.5/5	Jul 2012	599	ebay.com
6.		Panasonic G6	4/5	+ +	..	..	5/5	4.5/5	Apr 2013	599	ebay.com
7.		Panasonic GH2	5/5	+ +	..	79/100	4.5/5	5/5	Sep 2010	899	ebay.com
8.		Panasonic GH3	5/5	+ +	..	79/100	4.5/5	4.5/5	Sep 2012	1,299	ebay.com
9.		Panasonic GM5	3.5/5	+	..	77/100	5/5	4.5/5	Sep 2014	749	ebay.com
10.		Panasonic GX1	3/5	+	..	77/100	4.5/5	4.5/5	Nov 2011	699	ebay.com
11.		Panasonic GX7	4/5	+	..	79/100	5/5	5/5	Aug 2013	999	ebay.com
12.		Panasonic LX100	5/5	+ +	..	85/100	5/5	5/5	Sep 2014	899	ebay.com
13.		Ricoh GR	5/5	..	..	79/100	4.5/5	4.5/5	Apr 2013	799	ebay.com
14.		Sony A68	3/5	..	..	..	4/5	4/5	Nov 2015	699	ebay.com
15.		Sony A77 II	4/5	..	..	80/100	4.5/5	5/5	May 2014	1,199	ebay.com
16.		Sony A5100	4.5/5	+	..	..	4.5/5	5/5	Aug 2014	549	ebay.com
17.		Sony A6000	5/5	+	4.5/5	80/100	4.5/5	5/5	Feb 2014	599	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. A score, therefore, has to be seen in close connection to the price and market introduction time of the camera, and comparisons of ratings among very different cameras or across long time periods have little meaning. It should also be noted that some of the review sites have over time altered the way they render their verdicts.

Check GM1 offers at
ebay.com
Check A58 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. As an alternative, you can also directly jump to any one of the listed comparisons that were previously generated by the CAM-parator tool.

~

Check GM1 offers at
ebay.com
Check A58 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.