Sony A1 vs A9 II

The Sony A1 and the Sony Alpha A9 II are two professional cameras that were revealed to the public, respectively, in January 2021 and October 2019. Both the A1 and the A9 II are mirrorless interchangeable lens cameras that are equipped with a full frame sensor. The A1 has a resolution of 49.8 megapixels, whereas the A9 II provides 24 MP.

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

Headline Specifications

Sony A1		Sony A9 II
Mirrorless system camera		Mirrorless system camera
Sony E mount lenses		Sony E mount lenses
49.8 MP – Full Frame sensor		24 MP – Full Frame sensor
8k/30p Video		4K/30p Video
ISO 100-32,000 (50 - 102,400)		ISO 100-51,200 (50 - 204,800)
Electronic viewfinder (9437k dots)		Electronic viewfinder (3686k dots)
3.0" LCD – 1440k dots		3.0" LCD – 1440k dots
Tilting touchscreen		Tilting touchscreen
10 shutter flaps per second		20 shutter flaps per second
In-body stabilization		In-body stabilization
Weathersealed body		Weathersealed body
530 shots per battery charge		690 shots per battery charge
129 x 97 x 81 mm, 737 g		129 x 96 x 76 mm, 678 g

Check A1 price at
amazon.com
Check A9 II price at
amazon.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Sony A1 and the Sony Alpha A9 II? 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 Sony A1 and the Sony A9 II. 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 Sony A9 II is somewhat smaller (1 percent) than the Sony A1. Moreover, the A9 II is markedly lighter (8 percent) than the A1. 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 Sony FE 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 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.		Sony A1	129 mm	97 mm	81 mm	737 g	530	Y	Jan 2021	US$ 6 499	amazon.com
2.		Sony A9 II	129 mm	96 mm	76 mm	678 g	690	Y	Oct 2019	US$ 4 499	amazon.com
3.		Sony A7 III	127 mm	96 mm	74 mm	650 g	610	Y	Feb 2018	US$ 1 999	amazon.com
4.		Sony A7 IV	131 mm	96 mm	80 mm	659 g	580	Y	Oct 2021	US$ 2 499	amazon.com
5.		Sony A7C	124 mm	71 mm	60 mm	509 g	740	Y	Sep 2020	US$ 1 799	amazon.com
6.		Sony A7R II	127 mm	96 mm	60 mm	625 g	290	Y	Jun 2015	US$ 3 199	ebay.com
7.		Sony A7R III	127 mm	96 mm	74 mm	650 g	650	Y	Oct 2017	US$ 3 199	ebay.com
8.		Sony A7R IIIA	127 mm	96 mm	74 mm	650 g	650	Y	Apr 2021	US$ 3 199	amazon.com
9.		Sony A7R IV	129 mm	96 mm	78 mm	665 g	670	Y	Jul 2019	US$ 3 499	ebay.com
10.		Sony A7R IVA	129 mm	96 mm	78 mm	665 g	670	Y	Apr 2021	US$ 3 499	amazon.com
11.		Sony A7R V	131 mm	97 mm	82 mm	723 g	530	Y	Oct 2022	US$ 3 899	amazon.com
12.		Sony A7S III	127 mm	97 mm	81 mm	699 g	600	Y	Jul 2020	US$ 3 499	amazon.com
13.		Sony A9	127 mm	96 mm	63 mm	673 g	650	Y	Apr 2017	US$ 4 499	ebay.com
14.		Sony A99 II	143 mm	104 mm	76 mm	849 g	490	Y	Sep 2016	US$ 3 199	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 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 A9 II was launched at a markedly lower price (by 31 percent) than the A1, which puts it into a different market segment. Normally, street prices remain initially close to the MSRP, but after a couple of months, the first discounts appear. 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 imaging sensor is at the core of digital cameras and its size is one of the main determining factors 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. 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 are more costly to manufacture and tend to lead to bigger and heavier cameras and lenses.

Both cameras under consideration feature a full frame sensor, but their sensors differ slightly in size. The sensor area in the A9 II is 2 percent smaller. They nevertheless have the same format factor of 1.0. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

In terms of chip-set technology, the A1 uses a more advanced image processing engine (Dual BIONZ XR) than the A9 II (BIONZ X), with benefits for noise reduction, color accuracy, and processing speed.

With 49.8MP, the A1 offers a higher resolution than the A9 II (24MP), but the A1 has smaller individual pixels (pixel pitch of 4.16μm versus 5.94μm for the A9 II). However, the A1 is a somewhat more recent model (by 1 year and 3 months) than the A9 II, and its sensor might have benefitted from technological advances during this time that enhance the light gathering capacity of its pixels. Coming back to sensor resolution, it should be mentioned that the A1 has no anti-alias filter installed, so that it can capture all the detail its 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 Sony A9 II are 30 x 20 inches or 76.2 x 50.8 cm for good quality, 24 x 16 inches or 61 x 40.6 cm for very good quality, and 20 x 13.3 inches or 50.8 x 33.9 cm for excellent quality prints.

Unlike the A9 II, 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 Sony A1 has a native sensitivity range from ISO 100 to ISO 32000, which can be extended to ISO 50-102400. The corresponding ISO settings for the Sony Alpha A9 II are ISO 100 to ISO 51200, with the possibility to increase the ISO range to 50-204800.

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.

Since 2007, DXO Mark has published sensor performance measurements that have been derived using a consistent methodology. This service assesses and scores the color depth ("DXO Portrait"), dynamic range ("DXO Landscape"), and low-light sensitivity ("DXO Sports") of camera sensors, and also publishes an overall camera score. Of the two cameras under review, the A1 has a notably higher overall DXO score than the A9 II (overall score 5 points higher), which gives it an advantage in terms of imaging quality. This advantage is based on 0.9 bits higher color depth, 0.5 EV in additional dynamic range, and 0.1 stops of reduced 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.		Sony A1	Full Frame	49.8	8640	5760	8k/30p	25.9	14.5	3163	98
2.		Sony A9 II	Full Frame	24.0	6000	4000	4K/30p	25.0	14.0	3434	93
3.		Sony A7 III	Full Frame	24.0	6000	4000	4K/30p	25.0	14.7	3730	96
4.		Sony A7 IV	Full Frame	32.7	7008	4672	4K/60p	25.4	14.7	3379	97
5.		Sony A7C	Full Frame	24.0	6000	4000	4K/30p	25.0	14.7	3407	95
6.		Sony A7R II	Full Frame	42.2	7952	5304	4K/30p	26.0	13.9	3434	98
7.		Sony A7R III	Full Frame	42.2	7952	5304	4K/30p	26.0	14.7	3523	100
8.		Sony A7R IIIA	Full Frame	42.2	7952	5304	4K/30p	26.0	14.7	3523	100
9.		Sony A7R IV	Full Frame	60.2	9504	6336	4K/30p	26.0	14.8	3344	99
10.		Sony A7R IVA	Full Frame	60.2	9504	6336	4K/30p	26.0	14.8	3344	99
11.		Sony A7R V	Full Frame	60.2	9504	6336	8k/24p	26.5	14.8	3187	100
12.		Sony A7S III	Full Frame	12.0	4240	2832	4K/120p	23.7	13.9	2520	86
13.		Sony A9	Full Frame	24.0	6000	4000	4K/30p	24.9	13.3	3517	92
14.		Sony A99 II	Full Frame	42.2	7952	5304	4K/30p	25.4	13.4	2317	92

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 A1 provides a higher video resolution than the A9 II. It can shoot video footage at 8k/30p, while the A9 II is limited to 4K/30p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. The two cameras under consideration 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 A9 II (9437k vs 3686k dots). The following table reports on some other key feature differences and similarities of the Sony A1, the Sony A9 II, and comparable 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.		Sony A1	9437	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
2.		Sony A9 II	3686	n	3.0 / 1440	tilting	Y	1/8000s	20.0/s	n	Y
3.		Sony A7 III	2359	n	3.0 / 922	tilting	Y	1/8000s	10.0/s	n	Y
4.		Sony A7 IV	3686	n	3.0 / 1037	swivel	Y	1/8000s	10.0/s	n	Y
5.		Sony A7C	2360	n	3.0 / 922	swivel	Y	1/4000s	10.0/s	n	Y
6.		Sony A7R II	2400	n	3.0 / 1229	tilting	n	1/8000s	5.0/s	n	Y
7.		Sony A7R III	3686	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
8.		Sony A7R IIIA	3686	n	3.0 / 2340	tilting	Y	1/8000s	10.0/s	n	Y
9.		Sony A7R IV	5760	n	3.0 / 1440	tilting	Y	1/8000s	10.0/s	n	Y
10.		Sony A7R IVA	5760	n	3.0 / 2340	tilting	Y	1/8000s	10.0/s	n	Y
11.		Sony A7R V	9440	n	3.2 / 2100	full-flex	Y	1/8000s	10.0/s	n	Y
12.		Sony A7S III	9440	n	3.0 / 1440	swivel	Y	1/8000s	10.0/s	n	Y
13.		Sony A9	3686	n	3.0 / 1440	tilting	Y	1/8000s	20.0/s	n	Y
14.		Sony A99 II	2400	Y	3.0 / 1229	full-flex	n	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 Sony A1 and the Sony A9 II 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 A1 writes its imaging data to CFexpress (type A) or SDXC cards, while the A9 II uses SDXC cards. Both cameras feature dual card slots, which can be very useful in case a memory card fails. Moreover, both cameras support UHS-II cards (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 Sony A1 and Sony Alpha A9 II 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.		Sony A1	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
2.		Sony A9 II	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
3.		Sony A7 III	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
4.		Sony A7 IV	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
5.		Sony A7C	Y	stereo / mono	Y	Y	micro	3.2	Y	Y	Y
6.		Sony A7R II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
7.		Sony A7R III	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
8.		Sony A7R IIIA	Y	stereo / mono	Y	Y	micro	3.2	Y	Y	Y
9.		Sony A7R IV	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
10.		Sony A7R IVA	Y	stereo / mono	Y	Y	micro	3.2	Y	Y	Y
11.		Sony A7R V	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
12.		Sony A7S III	Y	stereo / mono	Y	Y	full	3.2	Y	-	Y
13.		Sony A9	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	Y
14.		Sony A99 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	Y

Both cameras feature a PC Sync terminal to control professional strobe lights, which will be appreciated by studio photographers.

Both the A1 and the A9 II are recent models that are part of the current product line-up. The A9 II replaced the earlier Sony A9, while the A1 does not have a direct predecessor. Further information on the features and operation of the A1 and A9 II can be found, respectively, in the Sony A1 Manual (free pdf) or the online Sony A9 II Manual.

Review summary

So what conclusions can be drawn? Which of the two cameras – the Sony A1 or the Sony A9 II – has the upper hand? Is one clearly better than the other? The listing below highlights the relative strengths of the two models.

Reasons to prefer the Sony A1:

• More detail: Offers more megapixels (49.8 vs 24MP) with a 44% higher linear resolution.
• 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.
• Better image quality: Scores markedly higher (5 points) in the DXO overall assessment.
• Better jpgs: Has a more modern image processing engine (Dual BIONZ XR vs BIONZ X).
• Better video: Provides higher definition movie capture (8k/30p vs 4K/30p).
• More detailed viewfinder: Has higher resolution electronic viewfinder (9437k vs 3686k dots).
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.9x vs 0.78x).
• Faster data transfer: Supports a more advanced USB protocol (3.2 vs 3.1).
• More solid recording: Has a full-sized HDMI port for a sturdy connection to an external recorder.
• More modern: Is somewhat more recent (announced 1 year and 3 months after the A9 II).

Arguments in favor of the Sony Alpha A9 II:

• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• Faster burst: Shoots at higher frequency (20 vs 10 flaps/sec) to capture the decisive moment.
• Longer lasting: Gets more shots (690 versus 530) out of a single battery charge.
• Easier device pairing: Supports NFC for fast wireless image transfer over short distances.
• More affordable: Was introduced into a lower priced category (31 percent cheaper at launch).
• More heavily discounted: Has been on the market for longer (launched in October 2019).

If the count of individual advantages (bullet points above) is taken as a guide, the A1 is the clear winner of the match-up (11 : 6 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 wildlife photographer will view the differences between cameras in a way that diverges from the perspective of a family photog, and a person interested in architecture has distinct needs from a sports 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 Sony A1 and the Sony A9 II 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 incomplete and does no justice, for example, to the way the A1 or the A9 II perform in practice. 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.		Sony A1	5/5	o	4.5/5	93/100	4.5/5	5/5	Jan 2021	US$ 6 499	amazon.com
2.		Sony A9 II	..	..	5/5	90/100	5/5	5/5	Oct 2019	US$ 4 499	amazon.com
3.		Sony A7 III	..	+ +	4.5/5	89/100	5/5	5/5	Feb 2018	US$ 1 999	amazon.com
4.		Sony A7 IV	5/5	+ +	4.5/5	89/100	4.5/5	4.5/5	Oct 2021	US$ 2 499	amazon.com
5.		Sony A7C	3.5/5	..	3.5/5	86/100	4/5	4/5	Sep 2020	US$ 1 799	amazon.com
6.		Sony A7R II	5/5	+ +	5/5	90/100	5/5	5/5	Jun 2015	US$ 3 199	ebay.com
7.		Sony A7R III	..	+ +	4/5	90/100	4.5/5	5/5	Oct 2017	US$ 3 199	ebay.com
8.		Sony A7R IIIA	..	+ +	4/5	90/100	4.5/5	5/5	Apr 2021	US$ 3 199	amazon.com
9.		Sony A7R IV	5/5	+	4.5/5	91/100	4.5/5	5/5	Jul 2019	US$ 3 499	ebay.com
10.		Sony A7R IVA	5/5	+	4.5/5	91/100	4.5/5	5/5	Apr 2021	US$ 3 499	amazon.com
11.		Sony A7R V	5/5	+ +	4.5/5	92/100	..	..	Oct 2022	US$ 3 899	amazon.com
12.		Sony A7S III	4.5/5	+ +	5/5	91/100	4.5/5	5/5	Jul 2020	US$ 3 499	amazon.com
13.		Sony A9	5/5	+ +	4.8/5	89/100	5/5	5/5	Apr 2017	US$ 4 499	ebay.com
14.		Sony A99 II	..	..	4.5/5	85/100	4.5/5	4.5/5	Sep 2016	US$ 3 199	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

The above review scores should be interpreted 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. A score, therefore, has to be seen in close connection to the price and market introduction time 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. Also, please note that some of the review sites have changed their methodology and reporting over time.

Check A1 price at
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Check A9 II price at
amazon.com

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 make your choice using the following search menu. There is also a set of direct links to comparison reviews that other users of the CAM-parator app explored.

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