Digic 5 is announced

[Daniel Browning]

I was under the impression that a CCD was inherently less noisy than a CMOS sensor, in an apples for apples comparison.

It depends on what you mean by an apples-to-apples comparison. If you mean a completely biased, nonsensical comparison rigged by CCD manufacturers to make their product seem superior, then yes, CCD is less noisy. But if you mean any real life comparison made within the last decade, then no, CCD is not inherently less noisy. Once microlenses became prevalent, the playing field evened out.

As I understand it, the reason to use CMOS was cost and power consumption.

It's not cost. The theory behind CMOS being cheaper is that they require less semiconductor customizations than CCD for manufacturing and can ride the coattails of the much larger computer manufacturing lines. But in reality, the only company to ever actual attempt it failed terribly. It turns out that CMOS image sensors require just as much customization as CCD.


The difference in power consumption is so incredibly minute that it can only matter to the ultra-tiny mobile phones with teeny, tiny LCD screens. In anything bigger, like a smartphone or a digicam, the LCD and other components take up so much more battery power that the difference is entirely inconsequential.

The reason why Nikon has better ISO noise performance is their use of a CCD

First of all, the last time Nikon came out with a CCD-based DSLR was 7 YEARS ago, in 2004. Everything since has been CMOS. Furthermore, Canon's CMOS sensors of the time wiped the floor with Nikon's CCD. The noise was so much lower in Canon's CMOS that it wasn't even funny.


Of course, now the tables have turned, and Nikon's CMOS sensors (mostly made by Sony) are noticeably better than Canon's CMOS sensors.

Is the 75% noise reduction a function of the noise generated by the chip (which would be very good) or is it noise reduction algorithms (which is not so good since this reduces image quality).

It's certainly not the chip. However, that doesn't necessarily mean that it's noise reduction algorithms, either. It could just be a better de-Bayer algorithm, that provides the same detail with less noise.