Phase One takes lead in camera sensor test

Medium-format digital cameras, which have larger sensors and higher price tags than even high-end SLRs, didn't fare so well in earlier tests of sensor quality by measurement firm DxO Labs, but Phase One's newly tested top-end technology has risen to the top of the DxOMark Sensor test.

Phase One's 60-megapixel P65+ camera scored 89.1 on the test, edging out the Nikon D3X, which scored 88, according to data released Thursday. In addition, the 51.7-megapixel Hasselblad H3DII 50, an older model than Phase One's, scored 78.2. Click here to compare the two models and Nikon's D3X.

The DxOMark sensor test measures a camera sensor's dynamic range, color depth, and low-light performance. DxO Labs cautions that differences of less than 5 points aren't really distinguishable, and of course many other factors including price, lens quality, autofocus, and resolution factor into overall camera quality.

The P65+ features the best color performance yet, but DxO Labs said its comparatively good performance in low-light conditions helped it carry the day. … Read more

Sony SLR sensor ranks below Nikon, above Canon

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. … Read more

Sensor quality: SLRs erode medium-format lead

It looks like Canon and Nikon weren't blowing smoke when they said their high-end SLRs cameras will compete with medium-format digital cameras used almost exclusively by professionals.

Given the image quality advantages that SLRs with larger "full-frame" sensors have over mainstream and much less expensive models with smaller processors, one might have expected another quantum leap from costly high-end medium-format digital cameras with sensors twice the area of top-end SLRs. Not so, according to new DxOMark Sensor test results set for release Tuesday by French test and measurement firm DxO Labs.

The company tested image sensors from several medium-format cameras--the Mamiya ZD Back, Leaf Aptus 75S, Hasselblad H3DII 39, and Phase One P45+. These are the sorts of cameras used by fashion photographers and others who need lush tones, fine detail, and lots of megapixels to handle big photos such as magazine spreads.

But none outperformed the Nikon D3X SLR, whose score of 88 gives it the current top rank on DxO's sensor tests. … Read more

Tests show ups and downs of Four Thirds cameras

Panasonic's $670 G1 and Olympus' $540 E-520 and $450 E-410--that show both the advantages and disadvantages of the Four Thirds standards the companies use.

The Four Thirds system governs image sensor sizes and the mounting mechanism for interchangeable lenses on the companies' SLR cameras, and the companies announced a new variation called Micro Four Thirds for smaller cameras that have SLRs' interchangeable lenses but not SLRs' "reflex" mirror, which directs light through an optical viewfinder before a shot is taken.

Four Thirds SLRs have a smaller sensor than lower-end SLRs from market leaders Nikon and Canon, which poses image quality challenges because there's less surface area to gather light. However, the sensor size is the same for Four Thirds and Micro Four Thirds, which means that cameras using the latter have a much larger sensor than typical compact cameras have. … Read more

New Canon SLR bumps Sony on sensor test

One verdict is in on Canon's EOS 5D Mark II: its sensor ranks very high on DxO Labs' test of sensor performance.

The black-spot issue notwithstanding, Canon's new full-frame SLR came in at fourth place with a score of 79.0, bumping Sony's 78.9-scoring Alpha A900 down a peg but still trailing Canon's top-end EOS-1Ds Mark III at 80.3. Nikon's D700, the closest rival to the 5D Mark II, is a notch ahead at 80.5.

More relevant for the potential upgrade market, new Canon SLR's score is significantly better from that of its predecessor, the 5D, whose score is 70.9. On a pixel-by-pixel basis, the 12.8-megapixel 5D's sensor actually has a lower signal-to-noise ratio, but when measured over an entire 8x10 print, the 5D Mark II's higher 21.1-megapixel resolution wins on that measurement.

The DxOMark Sensor test measures how well a camera's sensor fares when it comes to dynamic range, color depth, and low-light performance. The test doesn't measure any number of other camera issues such as autofocus, value, or image processing. But it's still useful given DxO Labs' engineering rigor and the central role a sensor plays in the abilities of a camera.

Pixel-peepers have been devouring DxO's new statistics; the curious can try this link to a comparison of the 5D Mark II, Nikon D700, and Sony A900. However, it should be noted, DxO Labs considers that scores must be at least of 5 points apart to be significant.

There's been much discussion about whether the $2,700 5D Mark II performs better than the $6,500 1Ds Mark III, which has the same resolution. The DxOMark tests give the edge to the top-end model based on its better color and dynamic range--the ability to capture both bright and dark regions--but the 5D Mark II wins out in low-light performance. Digging deeper into the charts, though, the 5D Mark II fares better in dynamic range at higher ISOs.

All these cameras perform better than the common herd by virtue of full-frame sensors measuring 36x24mm, the size of a full frame of 35mm film. Most digital SLRs have a smaller sensor that can't capture as much information overall, but those models are vastly more affordable. … Read more