Kodak's 50-megapixel medium-format sensor

Lori Grunin | Jul 09, 2008

You thought Sony's 24-megapixel CMOS was high-res? Well, as Kodak's announcement of a 50-megapixel CCD shows, there's always room for more--pixels, that is.

Granted, that's a bit of an apples-to-oranges comparison. Sony's chip is designed for full-frame dSLR cameras, those with a sensor the size of a 35mm film frame (24 x 36mm), which generally go into pro-level handheld cameras. In contrast, Kodak's KAF-50100 CCD is 49.1 x 36.8mm, for medium-format digital photography which tends to be used more by commercial and fine art photographers in studio settings. The KAF-50100 is only the latest in Kodak's line of high-resolution medium-format CCDs. For instance, it joins Kodak's 39-megapixel KAF-39000 in the lineup, which now becomes the second highest-resolution sensor for non-scientific imaging. Hasselblad recently announced the H3DII-50, a camera based on the 50-megapixel CCD, in addition to its older 39-megapixel H3DII-39. Professionals fork over upwards of US$30,000 for models like these.

To fit more pixels on the same chip, Kodak had to perform some voodoo shrinkage on them; they're 6 microns, compared with 6.8 for the KAF-39000. Kodak claims that the chip has increased data throughput, which seems odd since the specs (which are admittedly stamped "preliminary") indicate a maximum throughput of 18MHz vs. 24MHz for the 39-megapixel CCD. On the other hand, the newer chip uses a four-channel output, up from two, so each output channel has to handle fewer rows and should therefore be able to refresh faster. The specs on the two cameras, however, show the lower-resolution version to be faster: 1.4 seconds per capture for the H3DII-39 over 1.1 seconds for the H3DII-50. That could simply be implementation-specific, though.

Other performance specs seem to take a hit, too; quantum efficiency (how successful the electrons are at getting where they need to go), blooming protection (how well the chip handles the electron overflow caused by bright light) and dynamic range seem to drop as well, despite Kodak's claim that "key performance parameters" are retained compared to the current 6.8-micron designs. The company also says the new chip consumes less power, but there are no specs to judge by. (Check out the specs yourself.)

But I'm not an engineer, so I'm sure someone will correct me if I'm wrong. Really, though, it does take some magic to cram that many more pixels on without losing anything. Since volume production isn't planned until Q4, Kodak's got some time to practice pulling rabbits out of a hat, though.

Via CNET Crave

Filed under: Digital Cameras
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