New Canon SLR bumps Sony on sensor test

The Canon 5D Mark II is the new fourth-place member of DxO Labs' test of image sensor scores.

(Credit: DxO Labs)

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.

The sensor on Canon's 5D Mark II fares significantly better than that on the 5D. (Click to enlarge.)

(Credit: DxO Labs)

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.

Black spots?
Not all is well, though, among 5D Mark II photographers. Some have found an issue where the camera produces dark spots immediately to the right of extremely bright areas. Though the spots aren't obvious from a distance, photographers accustomed to having their shots scrutinized by the reviewers at microstock sites have expressed worries that iStockphoto, for example, will reject the shots.

Some examples are visible on photos published by Stephan Hoerold, for example, when viewed close up; Andrew Yip also published examples. And his shots showed them despite having several image processing options turned off, which an earlier report said worked around the problem.

Two iStockphoto forum discussions have sprung up about the black spot issue, too. "I cancelled my pre-order with WolfCamera yesterday and I sent Canon an email telling them why. I don't want to deal with the hassle of getting a camera just to have to ship it back for repairs," wrote user swilmor in one forum post. "Kind of stinks because I was really looking forward to getting it so I can start submitting to Getty."

It also appears a similar problem afflicted an earlier high-end Canon SLR, the 1D Mark IIN, according to images posted in 2007 at the Fred Miranda forums.

(Via Adorama)