Olympus E-M1 III vs Panasonic G100

The Olympus OM-D E-M1 Mark III and the Panasonic Lumix DC-G100 (labelled Panasonic G110 in some countries) are two digital cameras that were announced, respectively, in February 2020 and June 2020. Both the E-M1 III and the G100 are mirrorless interchangeable lens cameras that are equipped with a Four Thirds sensor. Both cameras offer a resolution of 20.2 megapixels.

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

Headline Specifications

Olympus E-M1 III		Panasonic G100
Mirrorless system camera		Mirrorless system camera
Micro Four Thirds lenses		Micro Four Thirds lenses
20.2 MP – Four Thirds sensor		20.2 MP – Four Thirds sensor
4K/30p Video		4K/30p Video
ISO 200-25,600		ISO 200-25,600
Electronic viewfinder (2360k dots)		Electronic viewfinder (3680k dots)
3.0" LCD – 1037k dots		3.0" LCD – 1840k dots
Swivel touchscreen		Swivel touchscreen
18 shutter flaps per second		10 shutter flaps per second
In-body stabilization		Lens stabilization only
Weathersealed body		not weather sealed
420 shots per battery charge		270 shots per battery charge
134 x 91 x 69 mm, 580 g		116 x 83 x 54 mm, 352 g

Check E-M1 III offers at
ebay.com
Check G100 price at
amazon.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Olympus OM-D E-M1 Mark III and the Panasonic Lumix DC-G100? 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 Olympus E-M1 III and the Panasonic G100 is provided 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 dimensions 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 G100 is notably smaller (21 percent) than the Olympus E-M1 III. Moreover, the G100 is substantially lighter (39 percent) than the E-M1 III. It is worth mentioning in this context that the E-M1 III is splash and dust resistant, while the G100 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. In this particular case, both cameras feature the same lens mount, so that they can use the same lenses. You can compare the optics available in the Micro Four Thirds Lens Catalog. 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 E-M1 III gets 420 shots out of its Olympus BLH-1 battery, while the G100 can take 270 images on a single charge of its Panasonic DMW-BLG10 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	Street Price
1.		Olympus E-M1 III	134 mm	91 mm	69 mm	580 g	420	Y	Feb 2020	US$ 1 799	ebay.com
2.		Panasonic G100	116 mm	83 mm	54 mm	352 g	270	n	Jun 2020	US$ 649	amazon.com
3.		Olympus E-M1	130 mm	94 mm	63 mm	497 g	350	Y	Sep 2013	US$ 1 399	ebay.com
4.		Olympus E-M1 II	134 mm	91 mm	67 mm	574 g	440	Y	Sep 2016	US$ 1 999	ebay.com
5.		Olympus E-M1X	144 mm	147 mm	75 mm	997 g	870	Y	Jan 2019	US$ 2 999	ebay.com
6.		Olympus E-M5 III	125 mm	85 mm	50 mm	414 g	310	Y	Oct 2019	US$ 1 199	ebay.com
7.		OM System OM-1	135 mm	92 mm	73 mm	599 g	520	Y	Feb 2022	US$ 2 199	ebay.com
8.		Panasonic G3	115 mm	84 mm	47 mm	336 g	270	n	May 2011	US$ 599	ebay.com
9.		Panasonic G5	120 mm	83 mm	71 mm	396 g	320	n	Jul 2012	US$ 599	ebay.com
10.		Panasonic G6	122 mm	85 mm	71 mm	390 g	340	n	Apr 2013	US$ 599	ebay.com
11.		Panasonic G7	125 mm	86 mm	77 mm	410 g	350	n	May 2015	US$ 649	ebay.com
12.		Panasonic G9	137 mm	97 mm	92 mm	658 g	400	Y	Nov 2017	US$ 1 699	ebay.com
13.		Panasonic G95	130 mm	94 mm	77 mm	536 g	290	Y	Apr 2019	US$ 999	ebay.com
14.		Panasonic GH5	139 mm	98 mm	87 mm	725 g	410	Y	Jan 2017	US$ 1 999	ebay.com
15.		Panasonic GH5 II	139 mm	98 mm	87 mm	727 g	400	Y	May 2021	US$ 1 699	amazon.com
16.		Panasonic GX1	116 mm	68 mm	39 mm	318 g	320	n	Nov 2011	US$ 699	ebay.com
17.		Panasonic GX8	133 mm	78 mm	63 mm	487 g	330	Y	Jul 2015	US$ 1 199	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 G100 was launched at a markedly lower price (by 64 percent) than the E-M1 III, 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 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. 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.

Both cameras under consideration feature a Four Thirds sensor and have a format factor (sometimes also referred to as "crop factor") of 2.0. Within the spectrum of camera sensors, this places the review cameras among the medium-sized sensor cameras that aim to strike a balance between image quality and portability. Both cameras feature a native aspect ratio (sensor width to sensor height) of 4:3.

The two cameras under review do not only share the same sensor size, but also offer an identical resolution of 20.2 megapixels. This similarity in sensor specs implies that both the E-M1 III and the G100 have the same pixel density, as well as the same pixel size. It should, however, be noted that the G100 is a somewhat more recent model (by 4 months) than the E-M1 III, and its sensor might have benefitted from technological advances during this time. Coming back to sensor resolution, it should be mentioned that neither of the two cameras has an anti-alias filter installed, so they are able to capture all the detail the sensor resolves.

The E-M1 III has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.

Unlike the G100, the E-M1 III has the capacity to capture high quality composite images (80MP) 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 Olympus OM-D E-M1 Mark III has a native sensitivity range from ISO 200 to ISO 25600, which can be extended to ISO 64-25600. The corresponding ISO settings for the Panasonic Lumix DC-G100 are ISO 200 to ISO 25600, with the possibility to increase the ISO range to 100-25600.

In terms of underlying technology, the E-M1 III is build around a CMOS sensor, while the G100 uses a Live MOS 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.

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 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.		Olympus E-M1 III	Four Thirds	20.2	5184	3888	4K/30p	23.3	13.1	1356	76
2.		Panasonic G100	Four Thirds	20.2	5184	3888	4K/30p	23.3	13.2	1391	76
3.		Olympus E-M1	Four Thirds	15.9	4608	3456	1080/30p	23.0	12.7	757	73
4.		Olympus E-M1 II	Four Thirds	20.2	5184	3888	4K/30p	23.7	12.8	1312	80
5.		Olympus E-M1X	Four Thirds	20.2	5184	3888	4K/30p	23.2	13.0	1254	75
6.		Olympus E-M5 III	Four Thirds	20.2	5184	3888	4K/30p	23.3	13.1	1324	76
7.		OM System OM-1	Four Thirds	20.2	5184	3888	4K/60p	23.4	13.4	1553	77
8.		Panasonic G3	Four Thirds	15.8	4592	3448	1080/60i	21.0	10.6	667	56
9.		Panasonic G5	Four Thirds	15.9	4608	3456	1080/60p	21.4	11.6	618	61
10.		Panasonic G6	Four Thirds	15.9	4608	3456	1080/60p	21.3	11.5	639	61
11.		Panasonic G7	Four Thirds	15.8	4592	3448	4K/30p	22.8	12.4	904	71
12.		Panasonic G9	Four Thirds	20.2	5184	3888	4K/60p	23.1	12.8	1138	74
13.		Panasonic G95	Four Thirds	20.2	5184	3888	4K/30p	23.2	13.0	1273	75
14.		Panasonic GH5	Four Thirds	20.2	5184	3888	4K/60p	23.9	13.0	807	77
15.		Panasonic GH5 II	Four Thirds	20.2	5184	3888	4K/60p	23.7	13.1	1136	79
16.		Panasonic GX1	Four Thirds	15.8	4592	3448	1080/60p	20.8	10.6	703	55
17.		Panasonic GX8	Four Thirds	20.2	5184	3888	4K/30p	23.5	12.6	806	75
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. 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 (4K/30p).

Feature comparison

Apart from body and sensor, cameras can and do differ across a range of features. The two cameras under review are similar with respect to both having an electronic viewfinder. However, the one in the G100 offers a substantially higher resolution than the one in the E-M1 III (3680k vs 2360k dots). The adjacent table lists some of the other core features of the Olympus E-M1 III and Panasonic G100 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.		Olympus E-M1 III	2360	n	3.0 / 1037	swivel	Y	1/8000s	18.0/s	n	Y
2.		Panasonic G100	3680	n	3.0 / 1840	swivel	Y	1/500s	10.0/s	Y	n
3.		Olympus E-M1	2360	n	3.0 / 1037	tilting	Y	1/8000s	10.0/s	n	Y
4.		Olympus E-M1 II	2360	n	3.0 / 1037	swivel	Y	1/8000s	18.0/s	n	Y
5.		Olympus E-M1X	2360	n	3.0 / 1037	swivel	Y	1/8000s	18.0/s	n	Y
6.		Olympus E-M5 III	2360	n	3.0 / 1040	swivel	Y	1/8000s	10.0/s	n	Y
7.		OM System OM-1	5760	n	3.0 / 1640	swivel	Y	1/8000s	10.0/s	n	Y
8.		Panasonic G3	1440	n	3.0 / 460	swivel	Y	1/4000s	4.0/s	Y	n
9.		Panasonic G5	1440	n	3.0 / 920	swivel	Y	1/4000s	6.0/s	Y	n
10.		Panasonic G6	1440	n	3.0 / 1036	swivel	Y	1/4000s	7.0/s	Y	n
11.		Panasonic G7	2360	n	3.0 / 1040	swivel	Y	1/4000s	7.0/s	Y	n
12.		Panasonic G9	3680	Y	3.0 / 1040	swivel	Y	1/8000s	20.0/s	n	Y
13.		Panasonic G95	2360	n	3.0 / 1240	swivel	Y	1/4000s	9.0/s	Y	Y
14.		Panasonic GH5	3680	n	3.2 / 1620	swivel	Y	1/8000s	12.0/s	n	Y
15.		Panasonic GH5 II	3680	n	3.0 / 1840	swivel	Y	1/8000s	12.0/s	n	Y
16.		Panasonic GX1	optional	n	3.0 / 460	fixed	Y	1/4000s	4.2/s	Y	n
17.		Panasonic GX8	2360	n	3.0 / 1040	swivel	Y	1/8000s	10.0/s	n	Y
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One feature that differentiates the E-M1 III and the G100 is in-body image stabilization (IBIS). The E-M1 III reduces the risk of handshake-induced blur with all attached lenses, while the G100 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, both cameras under consideration feature an 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 Olympus E-M1 III and the Panasonic G100 both have 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.

Concerning the storage of imaging data, both the E-M1 III and the G100 write their files to SDXC cards. The E-M1 III features dual card slots, which can be very useful in case a memory card fails. In contrast, the G100 only has one slot. The E-M1 III supports UHS-II cards (on its first slot), while the G100 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 Olympus OM-D E-M1 Mark III and Panasonic Lumix DC-G100 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.		Olympus E-M1 III	Y	stereo / mono	Y	Y	micro	3.1	Y	-	Y
2.		Panasonic G100	Y	stereo / mono	Y	Y	micro	2.0	Y	-	Y
3.		Olympus E-M1	Y	stereo / mono	Y	-	micro	2.0	Y	-	-
4.		Olympus E-M1 II	Y	stereo / mono	Y	Y	micro	3.0	Y	-	-
5.		Olympus E-M1X	Y	stereo / mono	Y	Y	micro	3.0	Y	-	Y
6.		Olympus E-M5 III	Y	stereo / mono	Y	-	micro	2.0	Y	-	Y
7.		OM System OM-1	Y	stereo / mono	Y	Y	micro	3.0	Y	-	Y
8.		Panasonic G3	Y	stereo / mono	-	-	mini	2.0	-	-	-
9.		Panasonic G5	Y	stereo / mono	-	-	mini	2.0	-	-	-
10.		Panasonic G6	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
11.		Panasonic G7	Y	stereo / mono	Y	-	micro	2.0	Y	-	-
12.		Panasonic G9	Y	stereo / mono	Y	Y	full	3.0	Y	-	Y
13.		Panasonic G95	Y	stereo / mono	Y	Y	micro	2.0	Y	-	Y
14.		Panasonic GH5	Y	stereo / mono	Y	Y	full	3.1	Y	-	Y
15.		Panasonic GH5 II	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
16.		Panasonic GX1	Y	stereo / mono	-	-	mini	2.0	-	-	-
17.		Panasonic GX8	Y	stereo / mono	Y	-	micro	2.0	Y	Y	-

Studio photographers will appreciate that the Olympus E-M1 III (unlike the G100) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

The G100 is a recent model that features in the current product line-up of Panasonic. In contrast, the E-M1 III has been discontinued (but can be found pre-owned on ebay). As a replacement in the same line of cameras, the E-M1 III was succeeded by the OM System OM-1. Further information on the features and operation of the E-M1 III and G100 can be found, respectively, in the Olympus E-M1 III Manual (free pdf) or the online Panasonic G100 Manual.

Review summary

So what conclusions can be drawn? Is there a clear favorite between the Olympus E-M1 III and the Panasonic G100? Which camera is better? Below is a summary of the relative strengths of each of the two contestants.

Arguments in favor of the Olympus OM-D E-M1 Mark III:

• High quality composites: Can combine several shots after pixel-shifting its sensor.
• Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.74x vs 0.73x).
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/500s) to freeze action.
• Faster burst: Shoots at higher frequency (18 vs 10 flaps/sec) to capture the decisive moment.
• Longer lasting: Can take more shots (420 versus 270) on a single battery charge.
• Better sealing: Is weather sealed to enable shooting in dusty or wet environments.
• Sharper images: Has hand-shake reducing image stabilization built-in.
• Faster data transfer: Supports a more advanced USB protocol (3.1 vs 2.0).
• 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.
• Faster buffer clearing: Supports a more advanced SD data transfer standard (UHS-II vs UHS-I).
• More heavily discounted: Has been on the market for longer (launched in February 2020).

Advantages of the Panasonic Lumix DC-G100:

• More detailed viewfinder: Has higher resolution electronic viewfinder (3680k vs 2360k dots).
• More detailed LCD: Has a higher resolution rear screen (1840k vs 1037k dots).
• More compact: Is smaller (116x83mm vs 134x91mm) and will fit more readily into a bag.
• Less heavy: Has a lower weight (by 228g or 39 percent) and is thus easier to take along.
• Easier fill-in: Has a small integrated flash to brighten shadows of backlit subjects.
• More affordable: Was introduced into a lower priced category (64 percent cheaper at launch).
• More modern: Was introduced somewhat (4 months) more recently.

If the count of individual advantages (bullet points above) is taken as a guide, the E-M1 III is the clear winner of the match-up (13 : 7 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 sports photographer will view the differences between cameras in a way that diverges from the perspective of a street photog, and a person interested in family portraits has distinct needs from a landscape 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 Olympus E-M1 III and the Panasonic G100 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 E-M1 III and the G100 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 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	Street Price
1.		Olympus E-M1 III	5/5	..	5/5	83/100	4.5/5	4/5	Feb 2020	US$ 1 799	ebay.com
2.		Panasonic G100	4/5	..	4/5	78/100	4/5	4/5	Jun 2020	US$ 649	amazon.com
3.		Olympus E-M1	5/5	+ +	..	84/100	4.5/5	4.5/5	Sep 2013	US$ 1 399	ebay.com
4.		Olympus E-M1 II	5/5	+ +	5/5	85/100	4.5/5	4.5/5	Sep 2016	US$ 1 999	ebay.com
5.		Olympus E-M1X	4.5/5	o	5/5	85/100	4.5/5	..	Jan 2019	US$ 2 999	ebay.com
6.		Olympus E-M5 III	5/5	+	5/5	82/100	4.5/5	4.5/5	Oct 2019	US$ 1 199	ebay.com
7.		OM System OM-1	5/5	..	..	87/100	5/5	4.5/5	Feb 2022	US$ 2 199	ebay.com
8.		Panasonic G3	3/5	+ +	..	75/100	4.5/5	5/5	May 2011	US$ 599	ebay.com
9.		Panasonic G5	3/5	+ +	..	..	4.5/5	4.5/5	Jul 2012	US$ 599	ebay.com
10.		Panasonic G6	4/5	+ +	..	..	5/5	4.5/5	Apr 2013	US$ 599	ebay.com
11.		Panasonic G7	4/5	+ +	3.5/5	80/100	5/5	4.5/5	May 2015	US$ 649	ebay.com
12.		Panasonic G9	..	+ +	5/5	85/100	5/5	5/5	Nov 2017	US$ 1 699	ebay.com
13.		Panasonic G95	4.5/5	+	4.5/5	83/100	4.5/5	4.5/5	Apr 2019	US$ 999	ebay.com
14.		Panasonic GH5	4.5/5	+ +	..	85/100	4.5/5	5/5	Jan 2017	US$ 1 999	ebay.com
15.		Panasonic GH5 II	4.5/5	..	4.5/5	85/100	4.5/5	5/5	May 2021	US$ 1 699	amazon.com
16.		Panasonic GX1	3/5	+	..	77/100	4.5/5	4.5/5	Nov 2011	US$ 699	ebay.com
17.		Panasonic GX8	5/5	+	..	82/100	4.5/5	4.5/5	Jul 2015	US$ 1 199	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 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.

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Other camera comparisons

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