In what way is this a remarkable accomplishment? it is exactly what basic analysis of signal level and the various noise sources suggests should happen, and what I would expect of any sensor.
It's a remarkable accomplishment because Canon seems to be the only company that has been able to put the theory into practice.
I mentioned before that I'd done some tests with my D60 comparing 'same exposures' at different ISOs and found that there was very little noise advantage at higher ISOs. To be completely objective and unbiased , there was some noise reduction in the deeper shadows, at higher ISOs, but none in the higher tones. There was therefore some
benefit to be gained with a high DR scene, using a high ISO, but very little benefit for a low DR scene.
Bjanes has also done similar tests with his Nikon D2X and found that that much-acclaimed camera also does not
show much noise improvement at higher than base ISO, with same exposures. Although, I understand the D2X offers a software option of reducing noise at high ISOs but which unfortunately also reduces resolution.
This is not the case with Canon's latest DSLRs which all show considerably less noise across the entire tonal range of the image, at high ISOs, and a particularly dramatic reduction in noise and increase in detail in the shadows at ISO 1600.
Perhaps the full significance of this achievement has escaped you. It's well known that many photos are not as sharp as they could be as a result of the photographer not using a tripod or failing to use a sufficiently fast shutter speed.
For this reason the Image Stabilisation technology in many Canon lenses is a much desired feature. However, use of IS does not help freeze movement of the subject. Nor does a tripod help in such situations. But a low noise, high ISO setting does help, a lot.
With my 5D, I can now take shots at ISO 1600 which are better in every respect than shots at ISO 400 with my D60. I see that as a 2 stop advantage which is just as significant as Canon's Image Stabilisation technology. In some respects it's more significant because the faster shutter speed freezes both camera shake and subject movement.
I hope the successor to the 5D will not only have a greater pixel count but a real
ISO 3200 setting with less noise than ISO 1600 (with same exposure).
Can you do it, Canon? I'm in the market for such a camera.