OM System OM-1 vs OM-3

The OM System OM-1 and the OM System OM-3 are two enthusiast cameras that were officially introduced, respectively, in February 2022 and February 2025. Both the OM-1 and the OM-3 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

OM System OM-1		OM System OM-3
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/60p Video		4K/60p Video
ISO 80-25,600 (80 - 102,400)		ISO 80-25,600 (80 - 102,400)
Electronic viewfinder (5760k dots)		Electronic viewfinder (2360k dots)
3.0" LCD – 1640k dots		3.0" LCD – 1640k dots
Swivel touchscreen		Swivel touchscreen
10 shutter flaps per second		6 shutter flaps per second
In-body stabilization		In-body stabilization
Weathersealed body		Weathersealed body
520 shots per battery charge		590 shots per battery charge
135 x 92 x 73 mm, 599 g		139 x 89 x 46 mm, 496 g

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Going beyond this snapshot of core features and characteristics, what are the differences between the OM System OM-1 and the OM System OM-3? 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 side-by-side display below illustrates the physical size and weight of the OM System OM-1 and the OM System OM-3. The two cameras are presented according to their relative size. Three successive views from the front, the top, and the rear are shown. All width, height and depth measures are rounded to the nearest millimeter.

The OM-3 can be obtained in two different colors (black, silver), while the OM-1 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 OM System OM-1 and the OM System OM-3 are of equal size. However, the OM-3 is markedly lighter (17 percent) than the OM-1. 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. 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.

The battery packs of both cameras can be charged via USB, 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	Street Price
1.		OM System OM-1	135 mm	92 mm	73 mm	599 g	520	Y	Feb 2022	US$ 2 199	ebay.com
2.		OM System OM-3	139 mm	89 mm	46 mm	496 g	590	Y	Feb 2025	US$ 1 999	amazon.com
3.		Olympus E-M1 II	134 mm	91 mm	67 mm	574 g	440	Y	Sep 2016	US$ 1 999	ebay.com
4.		Olympus E-M1 III	134 mm	91 mm	69 mm	580 g	420	Y	Feb 2020	US$ 1 799	ebay.com
5.		OM System OM-1 II	135 mm	92 mm	73 mm	599 g	500	Y	Jan 2024	US$ 2 399	amazon.com
6.		OM System OM-5	125 mm	85 mm	50 mm	414 g	310	Y	Oct 2022	US$ 1 199	amazon.com
7.		OM System OM-5 II	125 mm	85 mm	50 mm	414 g	310	Y	Jun 2025	US$ 1 199	amazon.com
8.		Panasonic G9	137 mm	97 mm	92 mm	658 g	400	Y	Nov 2017	US$ 1 699	ebay.com
9.		Panasonic G9 II	134 mm	102 mm	90 mm	658 g	390	Y	Sep 2023	US$ 1 899	amazon.com
10.		Panasonic G95	130 mm	94 mm	77 mm	536 g	290	Y	Apr 2019	US$ 999	ebay.com
11.		Panasonic GH5	139 mm	98 mm	87 mm	725 g	410	Y	Jan 2017	US$ 1 999	ebay.com
12.		Panasonic GH5 II	139 mm	98 mm	87 mm	727 g	400	Y	May 2021	US$ 1 699	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 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 OM-3 was somewhat cheaper (by 9 percent) than the OM-1 at launch, but both cameras fall into the same price category. 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 sensor inside a digital camera is one of the key determinants 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. Furthermore, a large sensor camera will give the photographer more possibilities to use shallow depth-of-field in order to isolate a subject from the background. On the downside, larger sensors tend to be more expensive and 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 OM-1 and the OM-3 have the same pixel density, as well as the same pixel size. It should, however, be noted that the OM-3 is much more recent (by 2 years and 11 months) than the OM-1, and its sensor will 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.

Both cameras have the capacity to capture high quality composite images by combining multiple shots after shifting the sensor by miniscule distances. This multi-shot, pixel-shift mode is most suitable for photography of stationary objects (landscapes, studio scenes).

The OM System OM-1 has a native sensitivity range from ISO 80 to ISO 25600, which can be extended to ISO 80-102400. The OM System OM-3 offers exactly the same ISO settings.

Technology-wise, both cameras are equipped with Stacked BSI-CMOS (Stacked Backside Illuminated 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 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 table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar cameras.

Sensor Characteristics

		Camera Model	Sensor Class	Resolution (MP)	Horiz. Pixels	Vert. Pixels	Video Format	DXO Portrait	DXO Landscape	DXO Sports	DXO Overall
1.		OM System OM-1	Four Thirds	20.2	5184	3888	4K/60p	23.4	13.4	1553	77
2.		OM System OM-3	Four Thirds	20.2	5184	3888	4K/60p	23.4	13.7	1852	78
3.		Olympus E-M1 II	Four Thirds	20.2	5184	3888	4K/30p	23.7	12.8	1312	80
4.		Olympus E-M1 III	Four Thirds	20.2	5184	3888	4K/30p	23.3	13.1	1356	76
5.		OM System OM-1 II	Four Thirds	20.2	5184	3888	4K/60p	23.4	13.6	1749	78
6.		OM System OM-5	Four Thirds	20.2	5184	3888	4K/30p	23.4	13.4	1622	78
7.		OM System OM-5 II	Four Thirds	20.2	5184	3888	4K/30p	23.4	13.7	1889	78
8.		Panasonic G9	Four Thirds	20.2	5184	3888	4K/60p	23.1	12.8	1138	74
9.		Panasonic G9 II	Four Thirds	25.0	5776	4336	5.7K/60p	23.4	13.5	1710	78
10.		Panasonic G95	Four Thirds	20.2	5184	3888	4K/30p	23.2	13.0	1273	75
11.		Panasonic GH5	Four Thirds	20.2	5184	3888	4K/60p	23.9	13.0	807	77
12.		Panasonic GH5 II	Four Thirds	20.2	5184	3888	4K/60p	23.7	13.1	1136	79
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 can also record movies. Both cameras under consideration are equipped with sensors that have a sufficiently high read-out speed for moving images, and both provide the same movie specifications (4K/60p).

Feature comparison

Apart from body and sensor, cameras can and do differ across a range of features. The two cameras under consideration are similar with respect to both having an electronic viewfinder. However, the one in the OM-1 offers a substantially higher resolution than the one in the OM-3 (5760k vs 2360k dots). The table below summarizes some of the other core capabilities of the OM System OM-1 and OM System OM-3 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.		OM System OM-1	5760	n	3.0 / 1640	swivel	Y	1/8000s	10.0/s	n	Y
2.		OM System OM-3	2360	n	3.0 / 1640	swivel	Y	1/8000s	6.0/s	n	Y
3.		Olympus E-M1 II	2360	n	3.0 / 1037	swivel	Y	1/8000s	18.0/s	n	Y
4.		Olympus E-M1 III	2360	n	3.0 / 1037	swivel	Y	1/8000s	18.0/s	n	Y
5.		OM System OM-1 II	5760	n	3.0 / 1640	swivel	Y	1/8000s	10.0/s	n	Y
6.		OM System OM-5	2360	n	3.0 / 1040	swivel	Y	1/8000s	10.0/s	n	Y
7.		OM System OM-5 II	2360	n	3.0 / 1040	swivel	Y	1/8000s	10.0/s	n	Y
8.		Panasonic G9	3680	Y	3.0 / 1040	swivel	Y	1/8000s	20.0/s	n	Y
9.		Panasonic G9 II	3680	n	3.0 / 1840	swivel	Y	1/8000s	10.0/s	n	Y
10.		Panasonic G95	2360	n	3.0 / 1240	swivel	Y	1/4000s	9.0/s	Y	Y
11.		Panasonic GH5	3680	n	3.2 / 1620	swivel	Y	1/8000s	12.0/s	n	Y
12.		Panasonic GH5 II	3680	n	3.0 / 1840	swivel	Y	1/8000s	12.0/s	n	Y
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

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 OM System OM-1 and the OM System OM-3 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 OM-1 and the OM-3 write their files to SDXC cards. The OM-1 features dual card slots, which can be very useful in case a memory card fails. In contrast, the OM-3 only has one slot. Both cameras support UHS-II cards, which provide for Ultra High Speed data transfer of up to 312 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 OM System OM-1 and OM System OM-3 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.		OM System OM-1	Y	stereo / mono	Y	Y	micro	3.0	Y	-	Y
2.		OM System OM-3	Y	stereo / mono	Y	Y	micro	3.0	Y	-	Y
3.		Olympus E-M1 II	Y	stereo / mono	Y	Y	micro	3.0	Y	-	-
4.		Olympus E-M1 III	Y	stereo / mono	Y	Y	micro	3.1	Y	-	Y
5.		OM System OM-1 II	Y	stereo / mono	Y	Y	micro	3.0	Y	-	Y
6.		OM System OM-5	Y	stereo / mono	Y	-	micro	2.0	Y	-	Y
7.		OM System OM-5 II	Y	stereo / mono	Y	-	micro	2.0	Y	-	Y
8.		Panasonic G9	Y	stereo / mono	Y	Y	full	3.0	Y	-	Y
9.		Panasonic G9 II	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
10.		Panasonic G95	Y	stereo / mono	Y	Y	micro	2.0	Y	-	Y
11.		Panasonic GH5	Y	stereo / mono	Y	Y	full	3.1	Y	-	Y
12.		Panasonic GH5 II	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y

Studio photographers will appreciate that the OM System OM-1 (unlike the OM-3) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

The OM-3 is a recent model that features in the current product line-up of OM System. In contrast, the OM-1 has been discontinued (but can be found pre-owned on ebay). As a replacement in the same line of cameras, the OM-1 was succeeded by the OM System OM-1 II. Further information on the two cameras (e.g. user guides, manuals), as well as related accessories, can be found on the official OM System website.

Review summary

So how do things add up? Is the OM System OM-1 better than the OM System OM-3 or vice versa? Below is a summary of the relative strengths of each of the two contestants.

Reasons to prefer the OM System OM-1:

• More detailed viewfinder: Has higher resolution electronic viewfinder (5760k vs 2360k dots).
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.82x vs 0.69x).
• Faster burst: Shoots at higher frequency (10 vs 6 flaps/sec) to capture the decisive moment.
• 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 available for much longer (launched in February 2022).

Advantages of the OM System OM-3:

• Less heavy: Has a lower weight (by 103g or 17 percent) and is thus easier to take along.
• Longer lasting: Gets more shots (590 versus 520) out of a single battery charge.
• More modern: Reflects 2 years and 11 months of technical progress since the OM-1 launch.

If the count of individual advantages (bullet points above) is taken as a guide, the OM-1 emerges as the winner of the contest (6 : 3 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 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 OM System OM-1 and the OM System OM-3 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 OM-1 and the OM-3 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	Street Price
1.		OM System OM-1	5/5	..	..	87/100	5/5	4.5/5	Feb 2022	US$ 2 199	ebay.com
2.		OM System OM-3	..	..	..	86/100	..	..	Feb 2025	US$ 1 999	amazon.com
3.		Olympus E-M1 II	5/5	+ +	5/5	85/100	4.5/5	4.5/5	Sep 2016	US$ 1 999	ebay.com
4.		Olympus E-M1 III	5/5	..	5/5	83/100	4.5/5	4/5	Feb 2020	US$ 1 799	ebay.com
5.		OM System OM-1 II	..	..	..	..	..	..	Jan 2024	US$ 2 399	amazon.com
6.		OM System OM-5	5/5	..	4.5/5	83/100	5/5	4.5/5	Oct 2022	US$ 1 199	amazon.com
7.		OM System OM-5 II	..	..	..	..	..	..	Jun 2025	US$ 1 199	amazon.com
8.		Panasonic G9	..	+ +	5/5	85/100	5/5	5/5	Nov 2017	US$ 1 699	ebay.com
9.		Panasonic G9 II	5/5	..	4.5/5	87/100	..	4.5/5	Sep 2023	US$ 1 899	amazon.com
10.		Panasonic G95	4.5/5	+	4.5/5	83/100	4.5/5	4.5/5	Apr 2019	US$ 999	ebay.com
11.		Panasonic GH5	4.5/5	+ +	..	85/100	4.5/5	5/5	Jan 2017	US$ 1 999	ebay.com
12.		Panasonic GH5 II	4.5/5	..	4.5/5	85/100	4.5/5	5/5	May 2021	US$ 1 699	amazon.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The review scores listed above should be treated with care, though. The assessments were made in relation to similar cameras of the same technological generation. 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. 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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Check OM-3 price at
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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 make a corresponding selection in the search boxes below. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.

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