Noise level comparatives

[Sab]

Bob,

I am looking for a comparative on the noise / ISO levels between the 10mp sensor (as found on a 400D) and the 15 mp sensor (as found on a 50D).

Which camera produces more noise at ISO 400 to ISO 1600 (especially in ldecreasing light levels)

In general, more pixels equate to more noise, but, I assume that technology can/could overcome this.

Your thoughts will be appreciated.
 

[Bob Atkins]

It's a little complex because the visibility of noise in a final print (which is what counts) depends on print size, noise reduction and the pixel density. However overall I'd say that an older 10MP APS-C DSLR like the 400D (or 40D) doesn't really have any significant noise advantage over a newer camera such as the 50D as you can see from test results on this page:

http://www.bobatkins.com/photography/digital/canon_eos_50D_review_3.html