OM System OM-3 vs Sony A6700

The OM System OM-3 and the Sony Alpha A6700 are two enthusiast cameras that were officially introduced, respectively, in February 2025 and July 2023. Both the OM-3 and the A6700 are mirrorless interchangeable lens cameras that are based on a Four Thirds (OM-3) and an APS-C (A6700) sensor. The OM System has a resolution of 20.2 megapixels, whereas the Sony provides 25.6 MP.

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

Headline Specifications

OM System OM-3		Sony A6700
Mirrorless system camera		Mirrorless system camera
Micro Four Thirds lenses		Sony E mount lenses
20.2 MP – Four Thirds sensor		25.6 MP – APS-C sensor
4K/60p Video		4K/120p Video
ISO 80-25,600 (80 - 102,400)		ISO 100-32,000 (50 - 102,400)
Electronic viewfinder (2360k dots)		Electronic viewfinder (2360k dots)
3.0" LCD – 1640k dots		3.0" LCD – 1037k dots
Swivel touchscreen		Swivel touchscreen
6 shutter flaps per second		11 shutter flaps per second
In-body stabilization		In-body stabilization
Weathersealed body		Weathersealed body
590 shots per battery charge		570 shots per battery charge
139 x 89 x 46 mm, 496 g		122 x 69 x 64 mm, 493 g

Check OM-3 price at
amazon.com
Check A6700 price at
amazon.com

Going beyond this snapshot of core features and characteristics, what are the differences between the OM System OM-3 and the Sony Alpha A6700? 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 OM System OM-3 and the Sony A6700 are illustrated 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 size dimensions are rounded to the nearest millimeter.

The OM-3 can be obtained in two different colors (black, silver), while the A6700 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 A6700 is considerably smaller (32 percent) than the OM System OM-3. Moreover, the A6700 is slightly lighter (1 percent) than the OM-3. 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. 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 (OM-3) and the Sony E-Mount Lens Catalog (A6700). 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 OM-3 gets 590 shots out of its OM System BLX-1 battery, while the A6700 can take 570 images on a single charge of its Sony NP-FZ100 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 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-3	139 mm	89 mm	46 mm	496 g	590	Y	Feb 2025	EUR 1 999	amazon.com
2.		Sony A6700	122 mm	69 mm	64 mm	493 g	570	Y	Jul 2023	EUR 1 699	amazon.com
3.		Olympus E-M1 II	134 mm	91 mm	67 mm	574 g	440	Y	Sep 2016	EUR 1 999	ebay.com
4.		Olympus E-M1 III	134 mm	91 mm	69 mm	580 g	420	Y	Feb 2020	EUR 1 799	ebay.com
5.		Olympus E-M5 III	125 mm	85 mm	50 mm	414 g	310	Y	Oct 2019	EUR 1 199	ebay.com
6.		OM System OM-1	135 mm	92 mm	73 mm	599 g	520	Y	Feb 2022	EUR 2 199	ebay.com
7.		OM System OM-1 II	135 mm	92 mm	73 mm	599 g	500	Y	Jan 2024	EUR 2 399	amazon.com
8.		OM System OM-5	125 mm	85 mm	50 mm	414 g	310	Y	Oct 2022	EUR 1 299	amazon.com
9.		OM System OM-5 II	125 mm	85 mm	50 mm	414 g	310	Y	Jun 2025	EUR 1 299	amazon.com
10.		Panasonic G9	137 mm	97 mm	92 mm	658 g	400	Y	Nov 2017	EUR 1 699	ebay.com
11.		Panasonic G90	130 mm	94 mm	77 mm	536 g	290	Y	Apr 2019	EUR 999	ebay.com
12.		Sony A7 II	127 mm	96 mm	60 mm	599 g	350	Y	Nov 2014	EUR 2 099	ebay.com
13.		Sony A7C	124 mm	71 mm	60 mm	509 g	740	Y	Sep 2020	EUR 2 099	amazon.com
14.		Sony A77 II	143 mm	104 mm	81 mm	647 g	480	Y	May 2014	EUR 1 199	ebay.com
15.		Sony A6300	120 mm	67 mm	49 mm	404 g	400	Y	Feb 2016	EUR 1 099	ebay.com
16.		Sony A6500	120 mm	67 mm	53 mm	453 g	350	Y	Oct 2016	EUR 1 699	ebay.com
17.		Sony A6600	120 mm	67 mm	69 mm	503 g	810	Y	Aug 2019	EUR 1 599	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

The price is, of course, an important factor in any camera decision. The listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The A6700 was launched at a markedly lower price (by 30 percent) than the OM-3, 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. A large sensor will tend to have larger individual pixels that provide better low-light sensitivity, wider dynamic range, and richer color-depth than smaller pixel-units 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 are more costly to manufacture and tend to lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the OM System OM-3 features a Four Thirds sensor and the Sony A6700 an APS-C sensor. The sensor area in the A6700 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 OM-3 has a native 4:3 aspect ratio, while the one in the A6700 offers a 3:2 aspect.

With 25.6MP, the A6700 offers a higher resolution than the OM-3 (20.2MP), but the A6700 nevertheless has larger individual pixels (pixel pitch of 3.79μm versus 3.34μm for the OM-3) due to its larger sensor. However, the OM-3 is a somewhat more recent model (by 1 year and 6 months) than the A6700, and its sensor might 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 OM-3 has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

The resolution advantage of the Sony A6700 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A6700 for good quality output (200 dots per inch) amounts to 31 x 20.6 inches or 78.6 x 52.4 cm, for very good quality (250 dpi) 24.8 x 16.5 inches or 62.9 x 41.9 cm, and for excellent quality (300 dpi) 20.6 x 13.8 inches or 52.4 x 35 cm. The corresponding values for the OM System OM-3 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.

Unlike the A6700, the OM-3 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 OM System OM-3 has a native sensitivity range from ISO 80 to ISO 25600, which can be extended to ISO 80-102400. The corresponding ISO settings for the Sony Alpha A6700 are ISO 100 to ISO 32000, with the possibility to increase the ISO range to 50-102400.

In terms of underlying technology, the OM-3 is build around a Stacked BSI-CMOS sensor, while the A6700 uses a BSI-CMOS 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.

For many cameras, data on sensor performance has been reported by DXO Mark. 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 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.		OM System OM-3	Four Thirds	20.2	5184	3888	4K/60p	23.4	13.7	1852	78
2.		Sony A6700	APS-C	25.6	6192	4128	4K/120p	24.3	14.0	2329	86
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.		Olympus E-M5 III	Four Thirds	20.2	5184	3888	4K/30p	23.3	13.1	1324	76
6.		OM System OM-1	Four Thirds	20.2	5184	3888	4K/60p	23.4	13.4	1553	77
7.		OM System OM-1 II	Four Thirds	20.2	5184	3888	4K/60p	23.4	13.6	1749	78
8.		OM System OM-5	Four Thirds	20.2	5184	3888	4K/30p	23.4	13.4	1622	78
9.		OM System OM-5 II	Four Thirds	20.2	5184	3888	4K/30p	23.4	13.7	1889	78
10.		Panasonic G9	Four Thirds	20.2	5184	3888	4K/60p	23.1	12.8	1138	74
11.		Panasonic G90	Four Thirds	20.2	5184	3888	4K/30p	23.2	13.0	1273	75
12.		Sony A7 II	Full Frame	24.0	6000	4000	1080/60p	24.9	13.6	2449	90
13.		Sony A7C	Full Frame	24.0	6000	4000	4K/30p	25.0	14.7	3407	95
14.		Sony A77 II	APS-C	24.0	6000	4000	1080/60p	24.4	13.4	1013	82
15.		Sony A6300	APS-C	24.0	6000	4000	4K/30p	24.4	13.7	1437	85
16.		Sony A6500	APS-C	24.0	6000	4000	4K/30p	24.5	13.7	1405	85
17.		Sony A6600	APS-C	24.0	6000	4000	4K/30p	23.8	13.4	1497	82
Note: DXO values in italics represent estimates based on sensor size and age.

Many modern cameras cannot only take still pictures, but also record videos. Both cameras under consideration have a sensor with sufficiently fast read-out times for moving pictures, but the A6700 provides a faster frame rate than the OM-3. It can shoot movie footage at 4K/120p, while the OM System is limited to 4K/60p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. The OM-3 and the A6700 are similar in the sense that both feature an electronic viewfinder, which is helpful when framing images in bright sunlight. Moreover, their viewfinders offer an identical resolution of 2360k dots. The table below summarizes some of the other core capabilities of the OM System OM-3 and Sony A6700 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-3	2360	n	3.0 / 1640	swivel	Y	1/8000s	6.0/s	n	Y
2.		Sony A6700	2360	n	3.0 / 1037	swivel	Y	1/4000s	11.0/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.		Olympus E-M5 III	2360	n	3.0 / 1040	swivel	Y	1/8000s	10.0/s	n	Y
6.		OM System OM-1	5760	n	3.0 / 1640	swivel	Y	1/8000s	10.0/s	n	Y
7.		OM System OM-1 II	5760	n	3.0 / 1640	swivel	Y	1/8000s	10.0/s	n	Y
8.		OM System OM-5	2360	n	3.0 / 1040	swivel	Y	1/8000s	10.0/s	n	Y
9.		OM System OM-5 II	2360	n	3.0 / 1040	swivel	Y	1/8000s	10.0/s	n	Y
10.		Panasonic G9	3680	Y	3.0 / 1040	swivel	Y	1/8000s	20.0/s	n	Y
11.		Panasonic G90	2360	n	3.0 / 1240	swivel	Y	1/4000s	9.0/s	Y	Y
12.		Sony A7 II	2400	n	3.0 / 1230	tilting	n	1/8000s	5.0/s	n	Y
13.		Sony A7C	2360	n	3.0 / 922	swivel	Y	1/4000s	10.0/s	n	Y
14.		Sony A77 II	2359	Y	3.0 / 1229	full-flex	n	1/8000s	12.0/s	Y	Y
15.		Sony A6300	2359	n	3.0 / 922	tilting	n	1/4000s	11.0/s	Y	n
16.		Sony A6500	2359	n	3.0 / 922	tilting	Y	1/4000s	11.0/s	Y	Y
17.		Sony A6600	2359	n	3.0 / 922	tilting	Y	1/4000s	11.0/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-3 and the Sony A6700 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.

The OM-3 writes its imaging data to SDXC cards, while the A6700 uses SDXC or Memory Stick PRO Duo cards. 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-3 and Sony Alpha A6700 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-3	Y	stereo / mono	Y	Y	micro	3.0	Y	-	Y
2.		Sony A6700	Y	stereo / mono	Y	Y	YES	3.2	Y	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.		Olympus E-M5 III	Y	stereo / mono	Y	-	micro	2.0	Y	-	Y
6.		OM System OM-1	Y	stereo / mono	Y	Y	micro	3.0	Y	-	Y
7.		OM System OM-1 II	Y	stereo / mono	Y	Y	micro	3.0	Y	-	Y
8.		OM System OM-5	Y	stereo / mono	Y	-	micro	2.0	Y	-	Y
9.		OM System OM-5 II	Y	stereo / mono	Y	-	micro	2.0	Y	-	Y
10.		Panasonic G9	Y	stereo / mono	Y	Y	full	3.0	Y	-	Y
11.		Panasonic G90	Y	stereo / mono	Y	Y	micro	2.0	Y	-	Y
12.		Sony A7 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
13.		Sony A7C	Y	stereo / mono	Y	Y	micro	3.2	Y	Y	Y
14.		Sony A77 II	Y	stereo / mono	Y	-	mini	2.0	Y	Y	-
15.		Sony A6300	Y	stereo / mono	Y	-	micro	2.0	Y	Y	-
16.		Sony A6500	Y	stereo / mono	Y	-	micro	2.0	Y	Y	-
17.		Sony A6600	Y	stereo / mono	Y	Y	YES	2.0	Y	Y	Y

Both the OM-3 and the A6700 are recent models that are part of the current product line-up. The A6700 replaced the earlier Sony A6600, while the OM-3 does not have a direct predecessor. Further information on the two cameras (e.g. user guides, manuals), as well as related accessories, can be found on the official OM System and Sony websites.

Review summary

So how do things add up? Is the OM System OM-3 better than the Sony A6700 or vice versa? A synthesis of the relative strong points of each of the models is listed below.

Reasons to prefer the OM System OM-3:

• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• High quality composites: Can combine several shots after pixel-shifting its sensor.
• More detailed LCD: Has a higher resolution rear screen (1640k vs 1037k dots).
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
• More modern: Is somewhat more recent (announced 1 year and 6 months after the A6700).

Advantages of the Sony Alpha A6700:

• More detail: Has more megapixels (25.6 vs 20.2MP), which boosts linear resolution by 15%.
• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• Better image quality: Features bigger pixels on a larger sensor for higher quality imaging.
• Richer colors: The pixel size advantage translates into images with better, more accurate colors.
• More dynamic range: Larger pixels capture a wider spectrum of light and dark details.
• Better low-light sensitivity: Larger pixels means good image quality even under poor lighting.
• Better video: Provides higher movie framerates (4K/120p versus 4K/60p).
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.71x vs 0.69x).
• Faster burst: Shoots at higher frequency (11 vs 6 flaps/sec) to capture the decisive moment.
• More compact: Is smaller (122x69mm vs 139x89mm) and will fit more readily into a bag.
• Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
• More affordable: Was introduced into a lower priced category (30 percent cheaper at launch).
• More heavily discounted: Has been on the market for longer (launched in July 2023).

If the number of relative strengths (bullet points above) is taken as a guide, the A6700 is the clear winner of the contest (13 : 5 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 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 OM System OM-3 and the Sony A6700 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 the spec-sheets of cameras can offer a general idea of their imaging potential, it remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the OM-3 or the A6700. 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 following table reports the overall ratings of the cameras as published by some of the major 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-3	..	..	..	86/100	..	..	Feb 2025	EUR 1 999	amazon.com
2.		Sony A6700	4.5/5	+	4.5/5	88/100	4.5/5	4.5/5	Jul 2023	EUR 1 699	amazon.com
3.		Olympus E-M1 II	5/5	+ +	5/5	85/100	4.5/5	4.5/5	Sep 2016	EUR 1 999	ebay.com
4.		Olympus E-M1 III	5/5	..	5/5	83/100	4.5/5	4/5	Feb 2020	EUR 1 799	ebay.com
5.		Olympus E-M5 III	5/5	+	5/5	82/100	4.5/5	4.5/5	Oct 2019	EUR 1 199	ebay.com
6.		OM System OM-1	5/5	..	..	87/100	5/5	4.5/5	Feb 2022	EUR 2 199	ebay.com
7.		OM System OM-1 II	..	..	..	..	..	..	Jan 2024	EUR 2 399	amazon.com
8.		OM System OM-5	5/5	..	4.5/5	83/100	5/5	4.5/5	Oct 2022	EUR 1 299	amazon.com
9.		OM System OM-5 II	..	..	..	..	..	..	Jun 2025	EUR 1 299	amazon.com
10.		Panasonic G9	..	+ +	5/5	85/100	5/5	5/5	Nov 2017	EUR 1 699	ebay.com
11.		Panasonic G90	4.5/5	+	4.5/5	83/100	4.5/5	4.5/5	Apr 2019	EUR 999	ebay.com
12.		Sony A7 II	5/5	+	4/5	82/100	4.5/5	5/5	Nov 2014	EUR 2 099	ebay.com
13.		Sony A7C	3.5/5	..	3.5/5	86/100	4/5	4/5	Sep 2020	EUR 2 099	amazon.com
14.		Sony A77 II	4/5	..	..	80/100	4.5/5	5/5	May 2014	EUR 1 199	ebay.com
15.		Sony A6300	4.5/5	+	..	85/100	5/5	5/5	Feb 2016	EUR 1 099	ebay.com
16.		Sony A6500	5/5	+ +	3.5/5	85/100	4.5/5	4.5/5	Oct 2016	EUR 1 699	ebay.com
17.		Sony A6600	4/5	+	4/5	83/100	4.5/5	4/5	Aug 2019	EUR 1 599	amazon.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

Care should be taken when interpreting the review scores above, 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 comparing ratings of very distinct cameras or ones that are far apart in terms of their release date 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

Did this review help to inform your camera decision process? In case you would like to check on the differences and similarities of other camera models, just use the search menu below. As an alternative, you can also directly jump to any one of the listed comparisons that were previously generated by the CAM-parator tool.

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