Err... if you read carefully, it's not full frame vs crop... 5DII full frame sensor is 36mm x 24mm with 5616 x 3744 pixels, so a "single pixel" is around 6.4um. When you crop 3479 x 2324 pixels out of it, it's basically respresent a sensor size of around 22.3mm x 14.9mm (which is same as a 8MP APS-C sensor) using current technology. Please note that 350D had 3456 x 2304 pixels, so a "single pixel" is also around 6.4um.Hi,
IMHO, you should compare using camera with different pixel size, but with the same technology and image processing unit. My suggestion will be using 5DII and 60D as both basically use the same technology and image processing unit... the only different is the pixel size.
Basically, took a similar image using under similar shooting condition and camera setting (should not be a problem since both are current Canon DSLR). Crop out 3479 x 2324 from the image shoot using 5DII... this should simulate a 8MP APS-C sensor (with pixel size 6.4um... a 350D using current sensor and image processing techology). Now resize the 7D 18MP to the same resolution (3479 x 2324) and compare the noise performance.
Just my $0.02.
Have a nice day.
Naw... then you're getting into the Full frame/crop sensor debate... crop vs crop, full frame vs full frame... 5d2 and D700 or if you want to stick with canon, 7d vs rebel xs? Heck even the 5d vs 5d2.. but then you got 2 different generations of cameras all together... but you get my point.
The topics is about comparing noise performance of a shrinking High-MP vs Native Low-MP sensor, so in order to do a valid comparison, everything should be identical except sensor pixels count. So using 2 current DSLR from the same brand with different pixels size should be the best way to do it as the technology and image processing method between 5DII and 60D should be very identical except the sensor pixel size.
Have a nice day.