July 8, 2008 10:28 AM PDT

Kodak's 50-megapixel medium-format sensor

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Kodak 50-megapixel CCD

(Credit: Kodak)

update: 7/10/08: I made some errors in the original post, which I've corrected, plus added Kodak's comment.

You thought Sony's 24-megapixel CMOS was high res? Well, as Kodak's announcement on Tuesday 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 (24x36mm), which generally go into pro-level handheld cameras. In contrast, Kodak's KAF-50100 CCD is 49.1x36.8mm, 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 $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 with a maximum of 18MHz per output vs. 24MHz for the 50-megapixel and 39-megapixel CCDs, respectively. Since the newer chip uses a 4-channel output, up from 2, that's an overall bandwidth increase. While the specs on the two cameras show the higher-resolution version to be faster by one measure--1.4 seconds per capture for the H3DII-39 over 1.1 seconds for the H3DII-50--the higher-resolution model has an overall slower capture rate of 33 captures per minute vs. 39. I'd attribute that last slowdown to the larger 50mp files the camera has to process.

Other performance specs seem to take a hit; 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.)

Kodak's comment:

While there are changes in other specifications for this device compared to the current sensor, our customers have indicated that these are minor and will not significantly impact overall camera performance in these markets. For example, while blooming protection is indeed slightly lower for the new device, it is still well above the level of protection needed for this application. And while dynamic range is also a little lower, it is still above 70 dB, which is a critical threshold for this market.

That sounds reasonable to me. Really, though, it does take some magic to cram that many more pixels in a small space without losing anything. We'd look forward to seeing what Kodak pulls out of this hat, but we probably won't be lucky enough to get our hands on the camera. Do you want us to try?

Senior Editor Lori Grunin has been covering digital imaging for two decades, but her memory's kind of sketchy on the details. You can hear about it every week on Indecent Exposure, the podcast she co-hosts with Matt Fitzgerald.