Panasonic GM1 vs Sony A900

The Panasonic Lumix DMC-GM1 and the Sony Alpha A900 are two digital cameras that were revealed to the public, respectively, in October 2013 and September 2008. The GM1 is a mirrorless interchangeable lens camera, while the A900 is a DSLR. The cameras are based on a Four Thirds (GM1) and a full frame (A900) sensor. The Panasonic has a resolution of 15.8 megapixels, whereas the Sony provides 24.4 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 A900
Mirrorless system camera		Digital single lens reflex
Micro Four Thirds lenses		Sony A mount lenses
15.8 MP – Four Thirds sensor		24.4 MP – Full Frame sensor
1080/60i Video		no Video
ISO 200-25,600		ISO 200-3,200 (100 - 6,400)
No viewfinder, LCD framing		Optical viewfinder
3.0" LCD – 1036k dots		3.0" LCD – 922k dots
Fixed touchscreen		Fixed screen (not touch-sensitive)
5 shutter flaps per second		5 shutter flaps per second
Lens stabilization only		In-body stabilization
not weather sealed		Weathersealed body
230 shots per battery charge		880 shots per battery charge
99 x 55 x 30 mm, 204 g		156 x 117 x 82 mm, 895 g

Check GM1 offers at
ebay.com
Check A900 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 A900? 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 A900 are illustrated in the side-by-side display below. The two cameras are presented according to their relative size. Three successive views from the front, the top, and the rear are shown. All size dimensions are rounded to the nearest millimeter.

The GM1 can be obtained in three different colors (black, silver, red), while the A900 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 A900 is considerably larger (235 percent) than the Panasonic GM1. Moreover, the A900 is substantially heavier (339 percent) than the GM1. It is noteworthy in this context that the A900 is splash and dust-proof, while the GM1 does not feature any corresponding weather-sealing.

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 A900 can take 880 images on a single charge of its Sony NP-FM500H power pack.

The adjacent table lists the principal physical characteristics of the two cameras alongside a wider set of alternatives. 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 GM1	99 mm	55 mm	30 mm	204 g	230	n	Oct 2013	749	ebay.com
2.		Sony A900	156 mm	117 mm	82 mm	895 g	880	Y	Sep 2008	2,999	ebay.com
3.		Panasonic G3	115 mm	84 mm	47 mm	336 g	270	n	May 2011	599	ebay.com
4.		Panasonic G5	120 mm	83 mm	71 mm	396 g	320	n	Jul 2012	599	ebay.com
5.		Panasonic G6	122 mm	85 mm	71 mm	390 g	340	n	Apr 2013	599	ebay.com
6.		Panasonic GH2	124 mm	90 mm	76 mm	442 g	330	n	Sep 2010	899	ebay.com
7.		Panasonic GH3	133 mm	93 mm	82 mm	550 g	540	Y	Sep 2012	1,299	ebay.com
8.		Panasonic GM5	99 mm	60 mm	36 mm	211 g	220	n	Sep 2014	749	ebay.com
9.		Panasonic GX1	116 mm	68 mm	39 mm	318 g	320	n	Nov 2011	699	ebay.com
10.		Panasonic GX7	123 mm	71 mm	55 mm	402 g	350	n	Aug 2013	999	ebay.com
11.		Panasonic LX100	115 mm	66 mm	55 mm	393 g	300	n	Sep 2014	899	ebay.com
12.		Ricoh GR	117 mm	61 mm	35 mm	245 g	290	n	Apr 2013	799	ebay.com
13.		Sony A7S II	127 mm	96 mm	60 mm	627 g	370	Y	Sep 2015	2,999	ebay.com
14.		Sony A9	127 mm	96 mm	63 mm	673 g	650	Y	Apr 2017	4,499	ebay.com
15.		Sony A99	147 mm	111 mm	78 mm	812 g	500	Y	Sep 2012	2,799	ebay.com
16.		Sony A99 II	143 mm	104 mm	76 mm	849 g	490	Y	Sep 2016	3,199	ebay.com
17.		Sony A850	156 mm	117 mm	82 mm	895 g	880	Y	Aug 2009	1,999	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 naturally be influenced heavily by the price. The listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The GM1 was launched at a markedly lower price (by 75 percent) than the A900, 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.

Sensor comparison

The size of the imaging sensor is a crucial determinant 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 GM1 features a Four Thirds sensor and the Sony A900 a full frame sensor. The sensor area in the A900 is 283 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 2.0 and 1.0. The sensor in the GM1 has a native 4:3 aspect ratio, while the one in the A900 offers a 3:2 aspect.

With 24.4MP, the A900 offers a higher resolution than the GM1 (15.8MP), but the A900 nevertheless has larger individual pixels (pixel pitch of 5.94μm versus 3.77μm for the GM1) due to its larger sensor. However, the GM1 is a much more recent model (by 5 years and 1 month) than the A900, 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 A900 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A900 for good quality output (200 dots per inch) amounts to 30.2 x 20.2 inches or 76.8 x 51.2 cm, for very good quality (250 dpi) 24.2 x 16.1 inches or 61.4 x 41 cm, and for excellent quality (300 dpi) 20.2 x 13.4 inches or 51.2 x 34.1 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 A900 are ISO 200 to ISO 3200, with the possibility to increase the ISO range to 100-6400.

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 A900 offers substantially better image quality than the GM1 (overall score 13 points higher). The advantage is based on 1.4 bits higher color depth, 0.6 EV in additional dynamic range, and 1.1 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.		Panasonic GM1	Four Thirds	15.8	4592	3448	1080/60i	22.3	11.7	660	66
2.		Sony A900	Full Frame	24.4	6048	4032	none	23.7	12.3	1431	79
3.		Panasonic G3	Four Thirds	15.8	4592	3448	1080/60i	21.0	10.6	667	56
4.		Panasonic G5	Four Thirds	15.9	4608	3456	1080/60p	21.4	11.6	618	61
5.		Panasonic G6	Four Thirds	15.9	4608	3456	1080/60p	21.3	11.5	639	61
6.		Panasonic GH2	Four Thirds	15.9	4608	3456	1080/60i	21.2	11.3	655	60
7.		Panasonic GH3	Four Thirds	15.9	4608	3456	1080/60p	22.7	12.4	812	71
8.		Panasonic GM5	Four Thirds	15.8	4592	3448	1080/60p	22.1	11.7	721	66
9.		Panasonic GX1	Four Thirds	15.8	4592	3448	1080/60p	20.8	10.6	703	55
10.		Panasonic GX7	Four Thirds	15.8	4592	3448	1080/60p	22.6	12.2	718	70
11.		Panasonic LX100	Four Thirds	12.7	4112	3088	4K/30p	22.3	12.5	553	67
12.		Ricoh GR	APS-C	16.1	4928	3264	1080/30p	23.6	13.5	972	78
13.		Sony A7S II	Full Frame	12.0	4240	2832	4K/30p	23.6	13.3	2993	85
14.		Sony A9	Full Frame	24.0	6000	4000	4K/30p	24.9	13.3	3517	92
15.		Sony A99	Full Frame	24.0	6000	4000	1080/60p	25.0	14.0	1555	89
16.		Sony A99 II	Full Frame	42.2	7952	5304	4K/30p	25.4	13.4	2317	92
17.		Sony A850	Full Frame	24.4	6048	4032	none	23.8	12.2	1415	79

Many modern cameras are not only capable of taking still images, but can also record movies. The GM1 indeed provides movie recording capabilities, while the A900 does not. The highest resolution format that the GM1 can use is 1080/60i.

Feature comparison

Apart from body and sensor, cameras can and do differ across a range of features. For example, the A900 has an optical viewfinder, which can be very useful when shooting in bright sunlight. In contrast, the GM1 relies on live view and the rear LCD for framing. The table below summarizes some of the other core capabilities of the Panasonic GM1 and Sony A900 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.		Panasonic GM1	none	n	3.0 / 1036	fixed	Y	1/500s	5.0/s	Y	n
2.		Sony A900	optical	Y	3.0 / 922	fixed	n	1/8000s	5.0/s	n	Y
3.		Panasonic G3	1440	n	3.0 / 460	swivel	Y	1/4000s	4.0/s	Y	n
4.		Panasonic G5	1440	n	3.0 / 920	swivel	Y	1/4000s	6.0/s	Y	n
5.		Panasonic G6	1440	n	3.0 / 1036	swivel	Y	1/4000s	7.0/s	Y	n
6.		Panasonic GH2	1534	n	3.0 / 460	swivel	n	1/4000s	3.0/s	Y	n
7.		Panasonic GH3	1746	n	3.0 / 614	swivel	Y	1/4000s	6.0/s	Y	n
8.		Panasonic GM5	1166	n	3.0 / 921	fixed	Y	1/500s	5.8/s	n	n
9.		Panasonic GX1	optional	n	3.0 / 460	fixed	Y	1/4000s	4.2/s	Y	n
10.		Panasonic GX7	2760	n	3.0 / 1040	tilting	Y	1/8000s	5.0/s	Y	Y
11.		Panasonic LX100	2764	n	3.0 / 921	fixed	n	1/4000s	11.0/s	n	Y
12.		Ricoh GR	optional	n	3.0 / 1230	fixed	n	1/4000s	4.0/s	Y	n
13.		Sony A7S II	2400	n	3.0 / 1229	tilting	n	1/8000s	5.0/s	n	Y
14.		Sony A9	3686	n	3.0 / 1440	tilting	Y	1/8000s	20.0/s	n	Y
15.		Sony A99	2359	Y	3.0 / 1229	full-flex	n	1/8000s	6.0/s	n	Y
16.		Sony A99 II	2400	Y	3.0 / 1229	full-flex	n	1/8000s	12.0/s	n	Y
17.		Sony A850	optical	Y	3.0 / 922	fixed	n	1/8000s	3.0/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 GM1 has one, while the A900 does not. While the built-in flash of the GM1 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 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 A900 uses Compact Flash or Memory Stick PRO Duo cards. The A900 features dual card slots, which can be very useful in case a memory card fails. In contrast, the GM1 only has one slot.

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 A900 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 A900	Y	- / -	-	-	mini	2.0	-	-	-
3.		Panasonic G3	Y	stereo / mono	-	-	mini	2.0	-	-	-
4.		Panasonic G5	Y	stereo / mono	-	-	mini	2.0	-	-	-
5.		Panasonic G6	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
6.		Panasonic GH2	Y	stereo / mono	Y	-	mini	2.0	-	-	-
7.		Panasonic GH3	Y	stereo / mono	Y	Y	mini	2.0	Y	-	-
8.		Panasonic GM5	Y	stereo / mono	-	-	micro	2.0	Y	-	-
9.		Panasonic GX1	Y	stereo / mono	-	-	mini	2.0	-	-	-
10.		Panasonic GX7	Y	stereo / mono	-	-	mini	2.0	Y	Y	-
11.		Panasonic LX100	Y	stereo / mono	-	-	micro	2.0	Y	Y	-
12.		Ricoh GR	Y	mono / mono	-	-	micro	2.0	-	-	-
13.		Sony A7S II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
14.		Sony A9	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	Y
15.		Sony A99	Y	stereo / mono	Y	Y	mini	2.0	-	-	-
16.		Sony A99 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	Y
17.		Sony A850	Y	- / -	-	-	mini	2.0	-	-	-

It is notable that the GM1 offers wifi support, while the A900 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 A900 (unlike the GM1) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

Both the GM1 and the A900 have been discontinued, but can regularly be found used on ebay. The A900 was replaced by the Sony A99, while the GM1 was followed by the Panasonic GM5. Further information on the features and operation of the GM1 and A900 can be found, respectively, in the Panasonic GM1 Manual (free pdf) or the online Sony A900 Manual.

Review summary

So what conclusions can be drawn? Which of the two cameras – the Panasonic GM1 or the Sony A900 – 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.

Advantages of the Panasonic Lumix DMC-GM1:

• Broader imaging potential: Can record not only still images but also 1080/60i movies.
• More detailed LCD: Has a higher resolution rear screen (1036k vs 922k 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 156x117mm) and thus needs less room in the bag.
• Less heavy: Is lighter (by 691g or 77 percent) and hence easier to carry around.
• More legacy lens friendly: Can take a broad range of non-native lenses via adapters.
• Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
• Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
• More affordable: Was introduced into a lower priced category (75 percent cheaper at launch).
• More modern: Reflects 5 years and 1 month of technical progress since the A900 launch.

Reasons to prefer the Sony Alpha A900:

• More detail: Has more megapixels (24.4 vs 15.8MP), which boosts linear resolution by 27%.
• Better image quality: Scores substantially higher (13 points) in the DXO overall evaluation.
• Richer colors: Generates noticeably more natural colors (1.4 bits more color depth).
• More dynamic range: Captures a broader range of light and dark details (0.6 EV of extra DR).
• Better low-light sensitivity: Can shoot in dim conditions (1.1 stops ISO advantage).
• Easier framing: Has an optical viewfinder for image composition and settings control.
• Easier setting verification: Features a control panel on top to check shooting parameters.
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/500s) to freeze action.
• Longer lasting: Gets more shots (880 versus 230) out of a single battery charge.
• Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
• 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.
• 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.
• More heavily discounted: Has been around for much longer (launched in September 2008).

If the number of relative strengths (bullet points above) is taken as a guide, the A900 emerges as the winner of the match-up (15 : 12 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 A900 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 A900 in practical situations. 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 why expert reviews are important. 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.		Panasonic GM1	3/5	+	..	78/100	5/5	4.5/5	Oct 2013	749	ebay.com
2.		Sony A900	..	+ +	..	+ +	4.5/5	5/5	Sep 2008	2,999	ebay.com
3.		Panasonic G3	3/5	+ +	..	75/100	4.5/5	5/5	May 2011	599	ebay.com
4.		Panasonic G5	3/5	+ +	..	..	4.5/5	4.5/5	Jul 2012	599	ebay.com
5.		Panasonic G6	4/5	+ +	..	..	5/5	4.5/5	Apr 2013	599	ebay.com
6.		Panasonic GH2	5/5	+ +	..	79/100	4.5/5	5/5	Sep 2010	899	ebay.com
7.		Panasonic GH3	5/5	+ +	..	79/100	4.5/5	4.5/5	Sep 2012	1,299	ebay.com
8.		Panasonic GM5	3.5/5	+	..	77/100	5/5	4.5/5	Sep 2014	749	ebay.com
9.		Panasonic GX1	3/5	+	..	77/100	4.5/5	4.5/5	Nov 2011	699	ebay.com
10.		Panasonic GX7	4/5	+	..	79/100	5/5	5/5	Aug 2013	999	ebay.com
11.		Panasonic LX100	5/5	+ +	..	85/100	5/5	5/5	Sep 2014	899	ebay.com
12.		Ricoh GR	5/5	..	..	79/100	4.5/5	4.5/5	Apr 2013	799	ebay.com
13.		Sony A7S II	5/5	+	..	..	4.5/5	5/5	Sep 2015	2,999	ebay.com
14.		Sony A9	5/5	+ +	4.8/5	89/100	5/5	5/5	Apr 2017	4,499	ebay.com
15.		Sony A99	5/5	..	..	84/100	4.5/5	4.5/5	Sep 2012	2,799	ebay.com
16.		Sony A99 II	..	..	4.5/5	85/100	4.5/5	4.5/5	Sep 2016	3,199	ebay.com
17.		Sony A850	3/5	..	..	75/100	..	4.5/5	Aug 2009	1,999	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

Care should be taken when interpreting the review scores above, though. The ratings were established in reference to similarly priced cameras that were available in the market at the time of the review. 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 A900 offers at
ebay.com

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. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.

~

Check GM1 offers at
ebay.com
Check A900 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.