jvarszegi
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 p.3 #21 · 5DmkII less sharp than 5D! | |
Steve Spencer wrote:
brainiac wrote:
Well, I correctly predicted, in November last year, that the 1Ds3 would have a comparable noise performance (providing you want to make pictures, not crops) to the D3. I am going to be bold and make another prediction here: the 5D2 iso 12800 noise performance, optimally processed from raw, will look pretty much the same as that from the 1Ds3. Why?
(1) because Canon likely made some effort with the 1Ds3 sensor, so tweaks are unlikely to radically transform its performance, and
(2) sensor design and fabrication is a very expensive business in which costs are acutely sensitive to volume, so Canon would be foolish not to aim to use its latest sensor in more than one model at different price points, if it can get away with it, and
(3) Canon has stated that the 5D2 sensor is derived from the 1Ds3 design, and
(4) no detailed explanation has been offered of how the 5D2 sensor differs from that in the 1Ds3, a
Hi Richard,
Interesting analysis, but have you seen this description of the sensor from Rob Galbraith's web site:
"With a size of 24 x 36mm, 21.03 million image pixels and a pixel pitch of 6.4µm square, the 5D Mark II's CMOS sensor offers the identical pixel count in a sensor that's identical in size to the full-frame EOS-1Ds Mark III. The 5D Mark II's sensor also features the same light-gathering area within each pixel (called the fill ratio) and same microlens coverage over each pixel as the company's current flagship.
To achieve what Canon is saying will be the highest image quality and lowest noise ever to emerge from a Canon EOS digital SLR, they introduced several refinements: the array of red, green and blue coloured filters over the sensor have been made more transmissive, which effectively bumps up the sensor's light sensitivity, plus they tweaked the way the sensor's signal (the light it has gathered during the exposure) is amplified and then read out.
Canon is showing some serious confidence in the 5D Mark II's image sensor, and in particular its noise characteristics: they've given the camera an extended ISO range of 50-25,600, which is a three stop jump from the ISO 3200 upper limit of the EOS-1Ds Mark III (and the 5D as well).
The 5D Mark II incorporates Canon's Integrated Cleaning System in front of the sensor, but with a new anti-stick fluorine coating on the frontmost filter surface that's meant to better prevent slightly moist debris from clinging on, or for it to be more readily shaken off during a cleaning cycle."
If they made the filters more transmissive, then there might be real improvement in ISO performance. I think we will have to wait for real side by side test to really know.
That's interesting. IIRC, one of the delays with implementing the new Bayer sensor pattern by Kodak, involving the use of some clear pixels, is figuring out the edges of colored regions; per-color resolution at a given total sensor resolution obviously decreases when you make some pixels clear. However, the new push for high resolutions makes that less and less of a worry. Here's hoping for clear pixels someday soon-- and maybe even a black and white sensor.
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