Sony A900 vs RX0

The Sony Alpha A900 and the Sony Cyber-shot DSC-RX0 are two digital cameras that were revealed to the public, respectively, in September 2008 and August 2017. The A900 is a DSLR, while the RX0 is a fixed lens compact. The cameras are based on a full frame (A900) and an one-inch (RX0) sensor. The A900 has a resolution of 24.4 megapixels, whereas the RX0 provides 15.4 MP.

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

Headline Specifications

Sony A900		Sony RX0
Digital single lens reflex		Fixed lens compact camera
Sony A mount lenses		24mm f/4.0
24.4 MP – Full Frame sensor		15.4 MP – 1" sensor
no Video		1080/60p Video
ISO 200-3,200 (100 - 6,400)		ISO 125-12,800
Optical viewfinder		No viewfinder, LCD framing
3.0" LCD – 922k dots		1.5" LCD – 230k dots
Fixed screen (not touch-sensitive)		Fixed screen (not touch-sensitive)
5 shutter flaps per second		5.5 shutter flaps per second
In-body stabilization		no shake reduction
Weathersealed body		Waterproof body (10m)
880 shots per battery charge		240 shots per battery charge
156 x 117 x 82 mm, 895 g		59 x 41 x 30 mm, 110 g

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Going beyond this snapshot of core features and characteristics, what are the differences between the Sony Alpha A900 and the Sony Cyber-shot DSC-RX0? 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 Sony A900 and the Sony RX0 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 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 RX0 is considerably smaller (87 percent) than the Sony A900. 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. More than that, the RX0 is water-proof up to 10m and can, thus, be used for underwater photography.

The above size and weight comparisons are to some extent incomplete and possibly misleading, as the RX0 has a lens built in, whereas the A900 is an interchangeable lens camera that requires a separate lens. Attaching the latter will add extra weight and bulk to the setup.

Concerning battery life, the A900 gets 880 shots out of its Sony NP-FM500H battery, while the RX0 can take 240 images on a single charge of its Sony NP-BJ1 power pack. The power pack in the RX0 can be charged via the USB port, 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. 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 (USD)	Street Price
1.		Sony A900	156 mm	117 mm	82 mm	895 g	880	Y	Sep 2008	2,999	ebay.com
2.		Sony RX0	59 mm	41 mm	30 mm	110 g	240	Y	Aug 2017	699	ebay.com
3.		Canon 5D Mark III	152 mm	116 mm	76 mm	950 g	950	Y	Mar 2012	3,499	ebay.com
4.		Canon 5D Mark II	152 mm	114 mm	75 mm	850 g	850	Y	Sep 2008	3,499	ebay.com
5.		Nikon D700	147 mm	123 mm	77 mm	1074 g	1000	Y	Jul 2008	2,999	ebay.com
6.		Panasonic S1	149 mm	110 mm	97 mm	1017 g	400	Y	Feb 2019	2,499	amazon.com
7.		Sony RX0 II	59 mm	41 mm	35 mm	132 g	240	Y	Mar 2019	699	amazon.com
8.		Sony A7 III	127 mm	96 mm	74 mm	650 g	610	Y	Feb 2018	1,999	amazon.com
9.		Sony A9	127 mm	96 mm	63 mm	673 g	650	Y	Apr 2017	4,499	ebay.com
10.		Sony RX10 IV	133 mm	94 mm	145 mm	1095 g	400	Y	Sep 2017	1,699	amazon.com
11.		Sony A99 II	143 mm	104 mm	76 mm	849 g	490	Y	Sep 2016	3,199	ebay.com
12.		Sony RX10 III	133 mm	94 mm	127 mm	1051 g	420	Y	Mar 2016	1,499	ebay.com
13.		Sony A7S II	127 mm	96 mm	60 mm	627 g	370	Y	Sep 2015	2,999	ebay.com
14.		Sony RX10 II	129 mm	88 mm	102 mm	813 g	400	Y	Jun 2015	1,299	ebay.com
15.		Sony RX10	129 mm	88 mm	102 mm	813 g	420	Y	Oct 2013	1,299	ebay.com
16.		Sony A99	147 mm	111 mm	78 mm	812 g	500	Y	Sep 2012	2,799	ebay.com
17.		Sony A850	156 mm	117 mm	82 mm	895 g	880	Y	Aug 2009	1,999	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

Any camera decision will obviously take relative prices into account. The listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The RX0 was launched at a lower price than the A900, despite having a lens built in. 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. 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 tend to be associated with larger, more expensive camera bodies and lenses.

Of the two cameras under consideration, the Sony A900 features a full frame sensor and the Sony RX0 an one-inch sensor. The sensor area in the RX0 is 87 percent smaller. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.0 and 2.7. Both cameras have a native aspect ratio (sensor width to sensor height) of 3:2.

Technology-wise, the RX0 uses a more advanced image processing engine (BIONZ X) than the A900 (BIONZ), with benefits for noise reduction, color accuracy, and processing speed.

With 24.4MP, the A900 offers a higher resolution than the RX0 (15.4MP), but the A900 nevertheless has larger individual pixels (pixel pitch of 5.94μm versus 2.74μm for the RX0) due to its larger sensor. However, the RX0 is a much more recent model (by 8 years and 11 months) than the A900, and its sensor will have benefitted from technological advances during this time that further enhance the light gathering capacity of its pixels.

The resolution advantage of the Sony A900 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the A900 for good quality output (200 dots per inch) amounts to 30.2 x 20.2 inches or 76.8 x 51.2 cm, for very good quality (250 dpi) 24.2 x 16.1 inches or 61.4 x 41 cm, and for excellent quality (300 dpi) 20.2 x 13.4 inches or 51.2 x 34.1 cm. The corresponding values for the Sony RX0 are 24 x 16 inches or 61 x 40.6 cm for good quality, 19.2 x 12.8 inches or 48.8 x 32.5 cm for very good quality, and 16 x 10.7 inches or 40.6 x 27.1 cm for excellent quality prints.

The Sony Alpha A900 has a native sensitivity range from ISO 200 to ISO 3200, which can be extended to ISO 100-6400. The corresponding ISO settings for the Sony Cyber-shot DSC-RX0 are ISO 125 to ISO 12800 (no boost).

Technology-wise, both cameras are equipped with CMOS (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.

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"). Of the two cameras under review, the A900 provides substantially higher image quality than the RX0, with an overall score that is 11 points higher. This advantage is based on 1.3 bits higher color depth, 0.1 EV of lower dynamic range, and 1.4 stops in additional low light sensitivity. 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.		Sony A900	Full Frame	24.4	6048	4032	none	23.7	12.3	1431	79
2.		Sony RX0	1-inch	15.4	4800	3200	1080/60p	22.4	12.4	548	68
3.		Canon 5D Mark III	Full Frame	22.1	5760	3840	1080/30p	24.0	11.7	2293	81
4.		Canon 5D Mark II	Full Frame	21.0	5616	3744	1080/30p	23.7	11.9	1815	79
5.		Nikon D700	Full Frame	12.1	4256	2832	none	23.5	12.2	2303	80
6.		Panasonic S1	Full Frame	24.0	6000	4000	4K/60p	25.2	14.5	3333	95
7.		Sony RX0 II	1-inch	15.4	4800	3200	4K/30p	22.1	12.4	555	65
8.		Sony A7 III	Full Frame	24.0	6000	4000	4K/30p	25.0	14.7	3730	96
9.		Sony A9	Full Frame	24.0	6000	4000	4K/30p	24.9	13.3	3517	92
10.		Sony RX10 IV	1-inch	20.0	5472	3648	4K/30p	22.0	12.2	408	63
11.		Sony A99 II	Full Frame	42.2	7952	5304	4K/30p	25.4	13.4	2317	92
12.		Sony RX10 III	1-inch	20.0	5472	3648	4K/30p	23.1	12.6	472	70
13.		Sony A7S II	Full Frame	12.0	4240	2832	4K/30p	23.6	13.3	2993	85
14.		Sony RX10 II	1-inch	20.0	5472	3648	4K/30p	23.0	12.6	531	70
15.		Sony RX10	1-inch	20.0	5472	3648	1080/60p	22.9	12.6	474	69
16.		Sony A99	Full Frame	24.0	6000	4000	1080/60p	25.0	14.0	1555	89
17.		Sony A850	Full Frame	24.4	6048	4032	none	23.8	12.2	1415	79
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. The RX0 indeed provides for movie recording, while the A900 does not. The highest resolution format that the RX0 can use is 1080/60p.

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. For example, the A900 has an optical viewfinder, which can be very useful when shooting in bright sunlight. In contrast, the RX0 relies on live view and the rear LCD for framing. The following table reports on some other key feature differences and similarities of the Sony A900, the Sony RX0, 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 A900	optical	Y	3.0 / 922	fixed	n	1/8000s	5.0/s	n	Y
2.		Sony RX0	none	n	1.5 / 230	fixed	n	..	5.5/s	n	n
3.		Canon 5D Mark III	optical	Y	3.2 / 1040	fixed	n	1/8000s	6.0/s	n	n
4.		Canon 5D Mark II	optical	Y	3.0 / 920	fixed	n	1/8000s	3.9/s	n	n
5.		Nikon D700	optical	Y	3.0 / 922	fixed	n	1/8000s	8.0/s	Y	n
6.		Panasonic S1	5760	Y	3.2 / 2100	full-flex	Y	1/8000s	9.0/s	n	Y
7.		Sony RX0 II	none	n	1.5 / 230	tilting	n	..	5.5/s	n	n
8.		Sony A7 III	2359	n	3.0 / 922	tilting	Y	1/8000s	10.0/s	n	Y
9.		Sony A9	3686	n	3.0 / 1440	tilting	Y	1/8000s	20.0/s	n	Y
10.		Sony RX10 IV	2359	Y	3.0 / 1440	tilting	Y	1/2000s	24.0/s	Y	Y
11.		Sony A99 II	2400	Y	3.0 / 1229	full-flex	n	1/8000s	12.0/s	n	Y
12.		Sony RX10 III	2359	Y	3.0 / 1229	tilting	n	1/2000s	14.0/s	Y	Y
13.		Sony A7S II	2400	n	3.0 / 1229	tilting	n	1/8000s	5.0/s	n	Y
14.		Sony RX10 II	2359	Y	3.0 / 1229	tilting	n	1/3200s	14.0/s	Y	Y
15.		Sony RX10	1440	Y	3.0 / 1229	tilting	n	1/3200s	10.0/s	Y	Y
16.		Sony A99	2359	Y	3.0 / 1229	full-flex	n	1/8000s	6.0/s	n	Y
17.		Sony A850	optical	Y	3.0 / 922	fixed	n	1/8000s	3.0/s	n	Y
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One feature that is present on the A900, but is missing on the RX0 is a top-level LCD. While being, of course, smaller than the rear screen, the control panel conveys some of the essential shooting information and can be convenient for quick and easy settings verification.

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, the RX0 only has 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 A900 writes its imaging data to Compact Flash or Memory Stick PRO Duo cards, while the RX0 uses micro SDXC or Memory Stick Micro cards. The A900 features dual card slots, which can be very useful in case a memory card fails. In contrast, the RX0 only has one slot.

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 Alpha A900 and Sony Cyber-shot DSC-RX0 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 A900	Y	- / -	-	-	mini	2.0	-	-	-
2.		Sony RX0	-	stereo / mono	Y	-	micro	2.0	Y	-	Y
3.		Canon 5D Mark III	Y	mono / mono	Y	Y	mini	2.0	-	-	-
4.		Canon 5D Mark II	Y	mono / mono	Y	-	mini	2.0	-	-	-
5.		Nikon D700	Y	- / -	-	-	mini	2.0	-	-	-
6.		Panasonic S1	Y	stereo / mono	Y	Y	full	3.1	Y	-	Y
7.		Sony RX0 II	-	stereo / mono	Y	-	micro	2.0	Y	-	Y
8.		Sony A7 III	Y	stereo / mono	Y	Y	micro	3.1	Y	Y	Y
9.		Sony A9	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	Y
10.		Sony RX10 IV	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
11.		Sony A99 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	Y
12.		Sony RX10 III	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
13.		Sony A7S II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
14.		Sony RX10 II	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
15.		Sony RX10	Y	stereo / mono	Y	Y	micro	2.0	Y	Y	-
16.		Sony A99	Y	stereo / mono	Y	Y	mini	2.0	-	-	-
17.		Sony A850	Y	- / -	-	-	mini	2.0	-	-	-

It is notable that the A900 has a hotshoe, while the RX0 does not. This socket makes it possible to easily attach optional accessories, such as an external flash gun.

Studio photographers will appreciate that the Sony A900 (unlike the RX0) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

Both the A900 and the RX0 have been discontinued, but can regularly be found used on ebay. The A900 was replaced by the Sony A99, while the RX0 was followed by the Sony RX0 II. Further information on the features and operation of the A900 and RX0 can be found, respectively, in the Sony A900 Manual (free pdf) or the online Sony RX0 Manual.

Review summary

So what conclusions can be drawn? Which of the two cameras – the Sony A900 or the Sony RX0 – has the upper hand? Is one clearly better than the other? Below is a summary of the relative strengths of each of the two contestants.

Arguments in favor of the Sony Alpha A900:

• More detail: Offers more megapixels (24.4 vs 15.4MP) with a 26% higher linear resolution.
• Better image quality: Scores substantially higher (11 points) in the DXO overall assessment.
• Richer colors: Generates images with noticeably better colors (1.3 bits more color depth).
• Better low-light sensitivity: Requires less light for good images (1.4 stops ISO advantage).
• Easier framing: Has an optical viewfinder for image composition and settings control.
• Easier setting verification: Features an LCD display on top to control shooting parameters.
• Larger screen: Has a bigger rear LCD (3.0" vs 1.5") for image review and settings control.
• More detailed LCD: Has a higher resolution rear screen (922k vs 230k dots).
• More flexible: Can take a variety of interchangeable lenses, including specialty optics.
• Longer lasting: Can take more shots (880 versus 240) on a single battery charge.
• Sharper images: Has hand-shake reducing image stabilization built-in.
• Better lighting: Features a hotshoe and can thus hold and trigger an external flash gun.
• 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 September 2008).

Reasons to prefer the Sony Cyber-shot DSC-RX0:

• Better jpgs: Has a more modern image processing engine (BIONZ X vs BIONZ).
• Broader imaging potential: Can capture not only stills but also 1080/60p video.
• Less disturbing: Has an electronic shutter option for completely silent shooting.
• Ready to shoot: Comes with an integrated lens, while the A900 requires a separate lens.
• More compact: Is smaller (59x41mm vs 156x117mm) and will fit more readily into a bag.
• Less heavy: Has a lower weight even though it has a lens built in (unlike the A900).
• Easier travel charging: Can be conveniently charged via its USB port.
• Water-proof: Is rugged and sealed and can thus be used for underwater photography (up to 10m).
• Easier file upload: Has wifi built in for automatic backup or image transfer to the web.
• Easier wireless transfer: Supports Bluetooth for image sharing without cables.
• More affordable: Was introduced at a lower price, despite coming with a built-in lens.
• More modern: Reflects 8 years and 11 months of technical progress since the A900 launch.

If the count of relative strengths (bullet points above) is taken as a measure, the A900 emerges as the winner of the contest (15 : 12 points). However, the relevance of individual strengths will vary across photographers, so that you might want to apply your own weighing scheme to the summary points when reflecting and deciding 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 Sony A900 and the Sony RX0 place the cameras among the top in their class? Find out in the latest Best DSLR Camera and Best Prime Lens Compact Camera listings 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 incomplete and does no justice, for example, to the way the A900 or the RX0 perform in practice. 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 table below provides a synthesis of the camera assessments of some of the best known photo-gear 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 (USD)	Street Price
1.		Sony A900	..	+ +	..	+ +	4.5/5	5/5	Sep 2008	2,999	ebay.com
2.		Sony RX0	..	..	..	..	3.5/5	4/5	Aug 2017	699	ebay.com
3.		Canon 5D Mark III	..	+ +	..	82/100	4.5/5	4.5/5	Mar 2012	3,499	ebay.com
4.		Canon 5D Mark II	4/5	91/100	..	79/100	4/5	..	Sep 2008	3,499	ebay.com
5.		Nikon D700	..	89/100	..	+ +	4.5/5	4.5/5	Jul 2008	2,999	ebay.com
6.		Panasonic S1	4.5/5	+ +	4.5/5	88/100	4.5/5	4/5	Feb 2019	2,499	amazon.com
7.		Sony RX0 II	..	..	..	..	3.5/5	4/5	Mar 2019	699	amazon.com
8.		Sony A7 III	..	+ +	4.5/5	89/100	5/5	5/5	Feb 2018	1,999	amazon.com
9.		Sony A9	5/5	+ +	4.8/5	89/100	5/5	5/5	Apr 2017	4,499	ebay.com
10.		Sony RX10 IV	5/5	+	3.5/5	84/100	4.5/5	5/5	Sep 2017	1,699	amazon.com
11.		Sony A99 II	..	..	4.5/5	85/100	4.5/5	4.5/5	Sep 2016	3,199	ebay.com
12.		Sony RX10 III	5/5	+	..	84/100	4.5/5	4.5/5	Mar 2016	1,499	ebay.com
13.		Sony A7S II	5/5	+	..	..	4.5/5	5/5	Sep 2015	2,999	ebay.com
14.		Sony RX10 II	5/5	+ +	..	82/100	4.5/5	4/5	Jun 2015	1,299	ebay.com
15.		Sony RX10	5/5	+	..	80/100	4.5/5	4.5/5	Oct 2013	1,299	ebay.com
16.		Sony A99	5/5	..	..	84/100	4.5/5	4.5/5	Sep 2012	2,799	ebay.com
17.		Sony A850	3/5	..	..	75/100	..	4.5/5	Aug 2009	1,999	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. Hence, a score should always be seen in the context of the camera's market launch date and its price, and rating-comparisons among cameras that span long time periods or concern very differently equipped models make little sense. Also, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.

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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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