Megapixel vs. Megapixel

[urameatball]

the number of megapixels surely have an influence on picture quality at... say... 11x14, but it doesn't mean a 6mp would perform better than 4mp shot.
Other things to consider:
sensor - tiny crappy sensors at 6mp will never print as well as something like a 10D at 6mp. the 10D will give you MUCH more detail at 11x14.
glass - the explanation is obvious!

I think those are the most important factors... but then, I maybe wrong

 

[photobug]

It's not all about megapixels, and megapixels are not all created equal. Camera sensors (either CCD or CMOS) have X# of pixels (or photosites)/sensor size.

A 4 megapixel consumer camera with a tiny sensor will produce a picture that has much more noise than a 4 megapixel APS sized (DSLR) sensor. Simplified answer- the bigger the physical pixels, the lower the noise.

Obviously there are other factors at work, but it's a good rule of thumb. Go to the DPReview forums and do a search for pixel size or noise. There should be several threads that will be quite topical.

This phenomenon (pixel size) explains why the Sony 828 (8 megapixel) pics have so much more noise than DSLR pics do. The Canon 1D (4 megapixels), which has a larger sensor than 6 megapixel DSLRs produces quality images that match the 6 MP cameras very well up to about 20x24 (maybe larger) enlargements.

All in all it's not as obvious as it would all seem.