Originally Posted by codprawn
I wish people wouldn't keep going on about the number of megapixels. In most cases it means nothing - just another example of things being sold by numbers because that is all people understand.
It's nothing to do with the number of megapixels, more to do with the space around each pixel.
All compact including prosumer cameras suffer from small sensors with too many pixels crammed in. Each pixel effectively courses electrical interference with the pixel around it.
Olympus DSLR's wail good, suffer the same as they are on a four thirds sized sensor.
If you have a compact at 10mp it will be worse (in theory all though some manufacturers have started to over come this) than an four thirds DSLR which is then worse than an CMOS sensor in such as Canon's mid range DSLR's. You really begin to see the quality when you go to full frame sensors (same size as old 35mm film) in cameras Like the Canon 5D MKII, Nikon D700, Canon 1Ds MKIII, Nikon D3x.
It also comes down to the software in side. Noise reduction software in any camera should be turned off. Also some manufactures produce better filters in front of the sensor than others.
I've taken picture with a Canon 1Ds at 21.1 mega pixels that have less noise at ISO 1600 than a Canon 20D at 8 mega pixels. Fair enough the 1DS is newer tehcnology but it goes to show.
IMO the more quality pixels the better. Best for printing large, cropping and image alteration in photoshop.
Anyone in the market for cameras' should have a read through this site http://www.dpreview.com/
and find the camera your after in the camera data base.