Sony SLR sensor ranks below Nikon, above Canon

DxO Labs added scores for three Sony SLRs to its site for image sensor tests. (Click to enlarge.)

(Credit: DxO Labs)

Three midrange Sony SLRs now are included in DxO Labs' measurements of image sensor performance, and the Alpha A700 proves to be reasonably competitive.

Sony's A700, which costs about $1,100 with an 18-70mm lens, has a score of 66.3 on the test, which calculates how well the sensor handles color, a range brightness and darkness, and low-light shooting. That puts it behind the top-scoring camera with a comparably sized sensor, the Nikon D90, almost ties it with the Pentax K10D and Nikon D300, and gives it a a few points' lead over Canon's 40D and 50D.

Meanwhile, the A200 scores 62.9 and the A300 an even 64, according to the DxOMark Sensor test results that were updated Tuesday. A five-point difference makes a difference of about 1/3 stop in exposure, DxO says, meaning that a higher-scoring camera can attain the same raw image quality as a rival even though the higher-scoring camera is using a faster exposure or higher ISO.

DxO Labs, a French company, makes a business of measuring camera image quality, developing technology for image-processing hardware and software, and selling software to convert the raw files produced by higher-end cameras into less flexible but more convenient formats such as JPEG. The DxOMark score measures sensor performance based on the raw file, a foundation for overall image quality but only a facet of a camera's overall performance.

Almost all cameras must 'demosaic' data from the image sensor, which records light in a checkerboard pattern of red, green, and blue, to produce a JPEG image.

(Credit: DxO Labs)

The company postponed scoring the A700 because until the newer version 4.0 of its firmware, the camera performed noise-reduction processing on the green light captured by the sensor before generating the raw file. DxO frowns upon cameras reducing noise before the raw file is produced, in part because it misses out on steady improvements in software such as Photoshop that can convert raw images.

DxO's scores haven't been met with universal acclaim. In response to some criticisms and in an attempt to dispel some confusion, DxO has published a boiled-down DxOMark Sensor explanation.

For example, the company has this to say about sensor resolution, an issue that arose when comparing medium-format cameras with large, high-resolution sensors to high-end SLRs: "DxOMark Sensor and resolution are two independent metrics of sensor performance. As a consequence, just because camera A has more pixels than camera B (and thus sees more details) does not mean that its raw DxOMark Sensor score will be better. So before comparing cameras with DxOMark Sensor, it is important to first determine the resolution you are looking for."

The company also offers a more detailed DxOMark frequently asked questions page.

[tutivillus]

Great info! But can you explain the headline? WHERE are the facts here in comparison?

I own Sony DSLRs and love them. In many instances Sony makes (or made) Nikon's sensors...so...please explain the comparison?

[Shankland]

Go to http://www.dxomark.com and click around to explore the results. I included one link to a comparison of the A200, A300, and A700 in the third paragraph of the story.

The overall ranking of all cameras can be found here: http://www.dxomark.com/index.php/eng/DxOMark-Sensor

[A-photo-mag-editor]

Sony does the fabrication on the current Niko nD-SLRs , but everything else, from the micro-lens array and anti-aliasing filters in front of the CMOS to the specs of the fabricated sensor to the processing engines that turn the electrical signals coming from the sensor into the "raw" image file ge (as well as doign the full processing of in camera produced JPEG or TIFF files) is done by Nikon designed (and possibly built) processor chips. ( my source for all of the above are my contacts at Nikon) That is why camera image quality isn't just about the name on the factory where the CMOS is fabricated.

[terminalblue]

silly question, but doesnt sony produce the sensors for canon cameras?

[sevort]

It is believed that Canon makes their own sensors; Nikon designs theirs, but outsources manufacturing to Sony or changes them according to their own specs.

[Shankland]

Sony makes its own SLR sensors, and Canon makes its own. Nikon doesn't make its sensors; it confirmed that Sony built the sensor for its new top-end D3X, but mostly such supplier relationships are pretty tightly held secrets.

Panasonic also makes sensors; Olympus uses them for its SLRs.

[businesscontacts]

Canon makes their own sensors with CMOS technology. Sony uses CCD technology.

[sevort]

Nikon did make their sensors in the past (D1 if my memory serves), so they are capable. They never confirmed Sony sensor in D3X, btw.

[Shankland]

@businesscontacts: Sony uses CMOS processors in its newer SLRs. Pretty much everybody does now--for one thing, it makes live view easier. CMOS also shows up in some compact cameras, for example Sony's new HX1 (http://reviews.cnet.com/digital-cameras/sony-cyber-shot-dsc/4505-6501_7-33543458.html).

[A-photo-mag-editor]

reply to Sevort's comment of 3/10/09 @ 10:35am

Nikon has confirmed that Sony does the fabrication of the CMOS imaging array in the D3X. As far as I know the only D-SLR Nikon fabricated their own imaging arrays for was the D2H series of cameras.

CMOS is popular with camera manufacturers for asevera lreasons, not the least of which are lower manufacturing costs and power consumption.

[jpsalvesen]

I appreciate dxomarks.com for the ability to compare cameras. However, the scores listed are calculated for viewing the images on-screen at 100%. That's rather articifial!

So, whenever I compare sensors, I always click on "print" in order to get a better view of how printouts would compare. After all, any camera above 3mpx will give me good, sharp images on my 24" iMac..

[jimafrost]

I thought the problem with the new Sony sensors was they got noisy really fast as the ISO rises, a problem Canon had well under control years ago and that Nikon took the lead in with the D300 and then D90 (both of which are superb). A quick check of dpreview.com confirms this; there is significant degredation even at ISO400, and it becomes serious by ISO800. Dpreview's notes on the A200 say:

"The differences in performance between the cameras in this comparison are only marginal at low sensitivities (only the E-420 is visibly softer than its counterparts) but from ISO400 upwards the different processing strategies become more apparent. At ISO 400 chroma and luminance noise starts to become visible in the Sony crops although at the same time the camera manages to maintain relatively good detail.

At very high sensitivities the noise reduction is much more heavy-handed resulting in visible smearing of fine detail without really eliminating the noise. You end up with a large amount of fairly unpleasantly intrusive blurred chroma noise blotches. In this comparison the EOS1000D delivers arguably the best balance between image detail and noise reduction."

I note that this generation of Sony cameras is a huge improvement over its predecessors, which were nothing short of horrible in the noise department, and had been getting worse with each generation as resolutions rose. Despite the relative improvement they are well behind the leaders in a lot of respects.

It used to be that Canon was the clear leader in low noise sensors at higher ISOs, but once Nikon decided to switch to CMOS, and design their own sensors rather than sourcing them from someone else (Sony, I think, but I can't remember for sure), they immediately leapfrogged.

I'll consider Sony an also-ran until they get noise under control.

jim frost
[e-mail]

[Shankland]

Comparing the Sony A700 to the Nikon D90 and Canon 50D, the noise looks pretty close, screen or print. (Click on SNR 18% to compare that attribute.)

http://tinyurl.com/aotlvv

The signal-to-noise comparison looks pretty competitive with Sony A200 vs. Canon XSi (450D) vs. Nikon D60, too:

http://tinyurl.com/apn3j2

I can't comment on what methodology differences lead DxO Labs and DP Review to differ on high-ISO noise control, but there are some data points, for what it's worth.

[tutivillus]

Allo? Sony is using CMOS in their cameras now. They are pretty much bagging the CCD. And yes, Nikon still uses many of Sony's sensors (or manufacturing) http://nikonrumors.com/2008/12/02/nikon-d3x-sensor-made-by-sony-designed-by-nikon.aspx

Fact is...it just doesn't matter, as we're all evangelists of our brands.

[daedbird]

That headline irks me - sounding as those are really the only camera makers out there. The story makes passing reference to Pentax, which had the second highest rating of the cameras named, despite the fact that model was replaced nearly two years ago!!!! And I didn't see any mention of Olympus.

Yes its nice that Sony, after buying Minolta, has come out with a powerful line of cameras (ones that are appealing to me) but there are so many good cameras out there, and focusing on just three companies makes no sense

How about a comparo between the CMOS and CCD cameras? Or just looking at the price range of each, utilizing this data (The A700, at $1,100 is close to the D90, but above the now-defunct K10 and $500 less than the D300, and I think the K10 is the only one using a CCD sensor)

[jmcoa]

I too am sick of brand defending or trashing. I use Nikon (film for many years, digital) and Sony (my main DSLR and lenses) and Canon (little P&S sucker). I have also owned every major brand over the years. Leica, Kodak, Pentax, Chinon!, Agfa (4x5 camera), Fuji/Zeiss/Schneider lenses, Sigma, you name it. I think the only camera I did not like was an overpriced Pentax 35mm point and shoot that made dark edged images.
What really matters is your creativity during the photographic process (that's art) and, these days, during post processing (art and some technology).