Olympus E-M10 IV vs Sony A1

The Olympus OM-D E-M10 Mark IV and the Sony A1 are two digital cameras that were announced, respectively, in August 2020 and January 2021. Both the E-M10 IV and the A1 are mirrorless interchangeable lens cameras that are based on a Four Thirds (E-M10 IV) and a full frame (A1) sensor. The Olympus has a resolution of 20.2 megapixels, whereas the Sony provides 49.8 MP.

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

Headline Specifications

Olympus E-M10 IV		Sony A1
Mirrorless system camera		Mirrorless system camera
Micro Four Thirds lenses		Sony E mount lenses
20.2 MP, Four Thirds Sensor		49.8 MP, Full Frame Sensor
4K/30p Video		8k/30p Video
ISO 200-25,600		ISO 100-32,000 (500 - 102,400)
Electronic viewfinder (2360k dots)		Electronic viewfinder (9437k dots)
3.0 LCD, 1040k dots		3.0 LCD, 1440k dots
Tilting touchscreen		Tilting touchscreen
15 shutter flaps per second		10 shutter flaps per second
In-body stabilization		In-body stabilization
not weather sealed		Weathersealed body
360 shots per battery charge		530 shots per battery charge
122 x 84 x 49 mm, 383 g		129 x 97 x 81 mm, 737 g

Going beyond this snapshot of core features and characteristics, what are the differences between the Olympus OM-D E-M10 Mark IV and the Sony A1? 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-M10 IV and the Sony A1 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 measures are rounded to the nearest millimeter.

The E-M10 IV can be obtained in two different colors (black, silver), while the A1 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 A1 is notably larger (22 percent) than the Olympus E-M10 IV. Moreover, the A1 is substantially heavier (92 percent) than the E-M10 IV. It is noteworthy in this context that the A1 is splash and dust-proof, while the E-M10 IV 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. 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 (E-M10 IV) and the Sony FE Lens Catalog (A1). 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-M10 IV gets 360 shots out of its BLS-50 battery, while the A1 can take 530 images on a single charge of its NP-FZ100 power pack. The battery packs of both cameras can be charged via USB, which can be very convenient when travelling.

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.		Olympus E-M10 IV	122 mm	84 mm	49 mm	383 g	360	n	Aug 2020	699
2.		Sony A1	129 mm	97 mm	81 mm	737 g	530	Y	Jan 2021	6,499
3.		Olympus E-M5 III	125 mm	85 mm	50 mm	414 g	310	Y	Oct 2019	1,199
4.		Olympus E-PL10	117 mm	68 mm	39 mm	380 g	350	n	Oct 2019	599
5.		Olympus E-PL9	117 mm	68 mm	39 mm	380 g	350	n	Feb 2018	599
6.		Olympus E-M10 III	122 mm	84 mm	50 mm	410 g	330	n	Aug 2017	649
7.		Olympus E-PL8	115 mm	67 mm	38 mm	357 g	350	n	Sep 2016	549
8.		Olympus PEN-F	125 mm	72 mm	37 mm	427 g	330	n	Jan 2016	1,199
9.		Olympus E-M10 II	120 mm	83 mm	47 mm	390 g	320	n	Aug 2015	649
10.		Olympus E-M10	119 mm	82 mm	46 mm	396 g	320	n	Jan 2014	699
11.		Olympus E-PL7	115 mm	67 mm	38 mm	357 g	350	n	Aug 2014	599
12.		Panasonic G100	116 mm	83 mm	54 mm	352 g	270	n	Jun 2020	649
13.		Sony A7S III	127 mm	97 mm	81 mm	699 g	600	Y	Jul 2020	3,499
14.		Sony A7R IV	129 mm	96 mm	78 mm	665 g	670	Y	Jul 2019	3,499
15.		Sony A7R III	127 mm	96 mm	74 mm	650 g	650	Y	Oct 2017	3,199
16.		Sony A9	127 mm	96 mm	63 mm	673 g	650	Y	Apr 2017	4,499
17.		Sony A7R II	127 mm	96 mm	60 mm	625 g	290	Y	Jun 2015	3,199
Notes: 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 retail prices at the time of the camera’s release place the model in the market relative to other models in the producer’s line-up and the competition. The E-M10 IV was launched at a markedly lower price (by 89 percent) than the A1, 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 Olympus E-M10 IV features a Four Thirds sensor and the Sony A1 a full frame sensor. The sensor area in the A1 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 E-M10 IV has a native 4:3 aspect ratio, while the one in the A1 offers a 3:2 aspect.

With 49.8MP, the A1 offers a higher resolution than the E-M10 IV (20.2MP), but the A1 nevertheless has larger individual pixels (pixel pitch of 4.16μm versus 3.34μm for the E-M10 IV) due to its larger sensor. Moreover, the A1 is a somewhat more recent model (by 5 months) than the E-M10 IV, and its sensor might have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixel-units. 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 resolution advantage of the Sony A1 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A1 for good quality output (200 dots per inch) amounts to 43.2 x 28.8 inches or 109.7 x 73.2 cm, for very good quality (250 dpi) 34.6 x 23 inches or 87.8 x 58.5 cm, and for excellent quality (300 dpi) 28.8 x 19.2 inches or 73.2 x 48.8 cm. The corresponding values for the Olympus E-M10 IV 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.

The A1 has on-sensor phase detect pixels, which results in fast and reliable autofocus acquisition even during live view operation.

Unlike the E-M10 IV, the A1 has the capacity to capture high quality composite images (YESMP) 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-M10 Mark IV has a native sensitivity range from ISO 200 to ISO 25600, which can be extended to ISO 100-25600. The corresponding ISO settings for the Sony A1 are ISO 100 to ISO 32000, with the possibility to increase the ISO range to 500-102400.

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"). 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.		Olympus E-M10 IV	Four Thirds	20.2	5184	3888	4K/30p	..	..	..	..
2.		Sony A1	Full Frame	49.8	8640	5760	8k/30p	..	..	..	..
3.		Olympus E-M5 III	Four Thirds	20.2	5184	3888	4K/30p	..	..	..	..
4.		Olympus E-PL10	Four Thirds	15.9	4608	3456	4K/30p	..	..	..	..
5.		Olympus E-PL9	Four Thirds	15.9	4608	3456	4K/30p	..	..	..	..
6.		Olympus E-M10 III	Four Thirds	15.9	4608	3456	4K/30p	..	..	..	..
7.		Olympus E-PL8	Four Thirds	15.9	4608	3456	1080/30p	..	..	..	..
8.		Olympus PEN-F	Four Thirds	20.2	5184	3888	1080/60p	23.1	12.4	894	74
9.		Olympus E-M10 II	Four Thirds	15.9	4608	3456	1080/60p	23.1	12.5	842	73
10.		Olympus E-M10	Four Thirds	15.9	4608	3456	1080/30p	22.8	12.3	884	72
11.		Olympus E-PL7	Four Thirds	15.9	4608	3456	1080/30p	22.7	12.4	873	72
12.		Panasonic G100	Four Thirds	20.2	5184	3888	4K/30p	..	..	..	..
13.		Sony A7S III	Full Frame	12.0	4240	2832	4K/120p	23.7	13.9	2520	86
14.		Sony A7R IV	Full Frame	60.2	9504	6336	4K/30p	26.0	14.8	3344	99
15.		Sony A7R III	Full Frame	42.2	7952	5304	4K/30p	26.0	14.7	3523	100
16.		Sony A9	Full Frame	24.0	6000	4000	4K/30p	24.9	13.3	3517	92
17.		Sony A7R II	Full Frame	42.2	7952	5304	4K/30p	26.0	13.9	3434	98

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, but the A1 provides a better video resolution than the E-M10 IV. It can shoot movie footage at 8k/30p, while the Olympus is limited to 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 A1 offers a substantially higher resolution than the one in the E-M10 IV (9437k vs 2360k dots). The table below summarizes some of the other core capabilities of the Olympus E-M10 IV and Sony A1 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 Size (inch)	LCD Resolution (000 dots)	LCD Attach- ment	Touch Screen (yes/no)	Mech Shutter Speed	Shutter Flaps (1/sec)	Built-in Flash (yes/no)	Built-in Image Stab
1.		Olympus E-M10 IV	2360	n	3.0	1040	tilting	Y	1/4000s	15.0	Y	Y
2.		Sony A1	9437	n	3.0	1440	tilting	Y	1/8000s	10.0	n	Y
3.		Olympus E-M5 III	2360	n	3.0	1040	swivel	Y	1/8000s	10.0	n	Y
4.		Olympus E-PL10	none	n	3.0	1040	tilting	Y	1/4000s	8.6	Y	Y
5.		Olympus E-PL9	none	n	3.0	1040	tilting	Y	1/4000s	8.6	Y	Y
6.		Olympus E-M10 III	2360	n	3.0	1040	tilting	Y	1/4000s	8.6	Y	Y
7.		Olympus E-PL8	optional	n	3.0	1037	tilting	Y	1/4000s	8.0	n	Y
8.		Olympus PEN-F	2360	n	3.0	1037	swivel	Y	1/8000s	10.0	n	Y
9.		Olympus E-M10 II	2360	n	3.0	1040	tilting	Y	1/4000s	8.0	Y	Y
10.		Olympus E-M10	1440	n	3.0	1037	tilting	Y	1/4000s	8.0	Y	Y
11.		Olympus E-PL7	optional	n	3.0	1037	tilting	Y	1/4000s	8.0	n	Y
12.		Panasonic G100	3680	n	3.0	1840	swivel	Y	1/500s	10.0	Y	n
13.		Sony A7S III	9440	n	3.0	1440	swivel	Y	1/8000s	10.0	n	Y
14.		Sony A7R IV	5760	n	3.0	1440	tilting	Y	1/8000s	10.0	n	Y
15.		Sony A7R III	3686	n	3.0	1440	tilting	Y	1/8000s	10.0	n	Y
16.		Sony A9	3686	n	3.0	1440	tilting	Y	1/8000s	20.0	n	Y
17.		Sony A7R II	2400	n	3.0	1229	tilting	n	1/8000s	5.0	n	Y

One difference between the cameras concerns the presence of an on-board flash. The E-M10 IV has one, while the A1 does not. While the built-in flash of the E-M10 IV 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, 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-M10 IV and the Sony A1 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 E-M10 IV writes its imaging data to SDXC cards, while the A1 uses CFexpress or SDXC cards. The A1 features dual card slots, which can be very useful in case a memory card fails. In contrast, the E-M10 IV 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 Olympus OM-D E-M10 Mark IV and Sony A1 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 Microphone	Internal Speaker	Microphone Port	Headphone Port	HDMI Port	USB Port	WiFi Support	NFC Support	Bluetooth Support
1.		Olympus E-M10 IV	Y	stereo	mono	-	-	micro	2.0	Y	-	Y
2.		Sony A1	Y	stereo	mono	Y	Y	mini	3.2	Y	-	Y
3.		Olympus E-M5 III	Y	stereo	mono	Y	-	micro	2.0	Y	-	Y
4.		Olympus E-PL10	Y	stereo	mono	-	-	micro	2.0	Y	-	Y
5.		Olympus E-PL9	Y	stereo	mono	-	-	micro	2.0	Y	-	Y
6.		Olympus E-M10 III	Y	stereo	mono	-	-	micro	2.0	Y	-	-
7.		Olympus E-PL8	Y	stereo	mono	-	-	micro	2.0	Y	-	-
8.		Olympus PEN-F	Y	stereo	mono	-	-	micro	2.0	Y	-	-
9.		Olympus E-M10 II	Y	stereo	mono	-	-	micro	2.0	Y	-	-
10.		Olympus E-M10	Y	stereo	mono	-	-	micro	2.0	Y	-	-
11.		Olympus E-PL7	Y	stereo	mono	-	-	micro	2.0	Y	-	-
12.		Panasonic G100	Y	stereo	mono	Y	Y	micro	2.0	Y	-	Y
13.		Sony A7S III	Y	stereo	mono	Y	Y	full	3.2	Y	-	Y
14.		Sony A7R IV	Y	stereo	mono	Y	Y	micro	3.1	Y	Y	Y
15.		Sony A7R III	Y	stereo	mono	Y	Y	micro	3.1	Y	Y	Y
16.		Sony A9	Y	stereo	mono	Y	Y	micro	2.0	Y	Y	Y
17.		Sony A7R II	Y	stereo	mono	Y	Y	micro	2.0	Y	Y	-

It is notable that the A1 has a headphone jack, which makes it possible to attach external headphones and monitor the quality of sound during the recording process. The E-M10 IV lacks such a headphone port.

Studio photographers will appreciate that the Sony A1 (unlike the E-M10 IV) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

Both the E-M10 IV and the A1 are recent models that are part of the current product line-up. The E-M10 IV replaced the earlier Olympus E-M10 III, while the A1 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 Olympus and Sony websites.

Review summary

So how do things add up? Is there a clear favorite between the Olympus E-M10 IV and the Sony A1? Which camera is better? Below is a summary of the relative strengths of each of the two contestants.

Reasons to prefer the Olympus OM-D E-M10 Mark IV:

• More selfie-friendly: Has an articulated screen that can be turned to be front-facing.
• Faster burst: Shoots at higher frequency (15 vs 10 flaps/sec) to capture the decisive moment.
• More compact: Is smaller (122x84mm vs 129x97mm) and thus needs less room in the bag.
• Less heavy: Is lighter (by 354g or 48 percent) and hence easier to carry around.
• Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
• More affordable: Was introduced into a lower priced category (89 percent cheaper at launch).
• More heavily discounted: Has been on the market for longer (launched in August 2020).

Advantages of the Sony A1:

• More detail: Has more megapixels (49.8 vs 20.2MP), which boosts linear resolution by 60%.
• High quality composites: Can combine several shots after pixel-shifting its sensor.
• 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 definition movie capture (8k/30p vs 4K/30p).
• Better live-view autofocus: Features on-sensor phase-detection for more confident autofocus.
• Better sound: Can connect to an external microphone for higher quality sound recording.
• Better sound control: Has a headphone port that enables audio monitoring while recording.
• More detailed viewfinder: Has higher resolution electronic viewfinder (9437k vs 2360k dots).
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.9x vs 0.62x).
• More detailed LCD: Has a higher resolution rear screen (1440k vs 1040k dots).
• Faster shutter: Has higher mechanical shutter speed (1/8000s vs 1/4000s) to freeze action.
• Longer lasting: Gets more shots (530 versus 360) out of a single battery charge.
• Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
• Faster data transfer: Supports a more advanced USB protocol (3.2 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.
• More modern: Was introduced somewhat (5 months) more recently.

If the count of individual advantages (bullet points above) is taken as a guide, the A1 is the clear winner of the contest (20 : 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 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 Olympus E-M10 IV and the Sony A1 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 specs-based evaluation of cameras can be instructive in revealing their potential as photographic tools, it remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the E-M10 IV or the A1. 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 where reviews by experts come in. The following table reports the overall ratings of the cameras as published by some of the major camera review sites (amateurphotographer [AP], cameralabs [CL], 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	DPR   score	EPZ   score	PB   score	Camera Launch	Launch Price (USD)	Street Price
1.		Olympus E-M10 IV	4.5/5	..	..	4.5/5	4.5/5	Aug 2020	699
2.		Sony A1	..	..	..	..	..	Jan 2021	6,499
3.		Olympus E-M5 III	5/5	+	82/100	4.5/5	4.5/5	Oct 2019	1,199
4.		Olympus E-PL10	..	..	77/100	..	4/5	Oct 2019	599
5.		Olympus E-PL9	..	+	..	4.5/5	4/5	Feb 2018	599
6.		Olympus E-M10 III	..	+	80/100	4.5/5	4.5/5	Aug 2017	649
7.		Olympus E-PL8	..	..	..	4.5/5	4/5	Sep 2016	549
8.		Olympus PEN-F	..	..	82/100	4.5/5	5/5	Jan 2016	1,199
9.		Olympus E-M10 II	4.5/5	+ +	80/100	5/5	5/5	Aug 2015	649
10.		Olympus E-M10	4/5	..	80/100	5/5	5/5	Jan 2014	699
11.		Olympus E-PL7	4/5	+	..	5/5	4/5	Aug 2014	599
12.		Panasonic G100	..	..	..	4/5	4/5	Jun 2020	649
13.		Sony A7S III	..	+ +	91/100	4.5/5	5/5	Jul 2020	3,499
14.		Sony A7R IV	5/5	+	91/100	4.5/5	5/5	Jul 2019	3,499
15.		Sony A7R III	..	+ +	90/100	4.5/5	5/5	Oct 2017	3,199
16.		Sony A9	5/5	+ +	89/100	5/5	5/5	Apr 2017	4,499
17.		Sony A7R II	5/5	+ +	90/100	5/5	5/5	Jun 2015	3,199
Notes: (+ +) 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. 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. Also, please note that some of the review sites have changed their methodology and reporting over time.

Other camera comparisons

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Specifications: Olympus E-M10 IV vs Sony A1

Below is a side-by-side comparison of the specs of the two cameras to facilitate a quick review of their differences and common features.

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