Megapixel & noise
First of all, i should say i'm a student and therefore don't print much at all. Aside from the usual 4x6s and couple of A4 prints, i don't know much about printing at all. I'm just trying to get my head around this relationship between megapixel count and noise level in prints. From what i've read, higher MP count on the same sized sensor will lead to greater amount of noise. However that doesn't matter because the worse noise level will be offset by the higher resolution. So this relationship leads me to a couple of questions.
If that relationship is true then why are camera manufacturers giving us small incremental increase in MP? why not just go straight from say 10MP to 20mp within one generation? is it too much of a technical challenge? The only reason i can think of is, because they can.
Also if that relationship is true, then how come some companies (Nikon & Olympus) are staying at the same MP count or even reducing it (ie. G10 - G11)?
What about taking extremes into account? like when the same sensor is improved (D3 - D3s), so the performance difference is widened. On the same sized sensor, is a 2nd generation 12MP sensor that starts off with way better noise performance going to give better result than a 18MP sensor with worse noise performance in medium size prints (say A3 size)?
Any answers will be appreciated. i don't do a lot of printing now, but i think i will in the future and these information will be very helpful.