Why's there 20mp on the 6d?

[Marsu42]

I am wondering why Canon put this sensor into 6d - the 5d3 seems to have the 22mp count because it's a multiple of 1080p and produces less moiré when downsizing to video resolution.

Is there any reason for the the way the 6d sensor is *except* marketing, i.e. keeping the tech spec even below the 5d2's 21mp? Maybe Canon gains a significant production advantage like less sensor waste for 6d and such is able to lower the price? Or is there any video- or stills-shooting related reason except that a little larger pixels produce a little less noise?

[Axilrod]

I think it has more to do with product differentiation and keeping it below the 5D3.  It may have helped it do better in low-light as well but it definitely didn't do anything positive for the video side of things.

[Marsu42]

I think it has more to do with product differentiation and keeping it below the 5D3.

I'm always happy to bash Canon marketing, but in this case I really wonder if there isn't more to it - maybe the increased dynamic range of the 6d?

The "less than 5d3" sounds like Canon but at the same time a little strange since people paying €3000 for a camera probably know that more mp isn't necessarily better, or we'd all be shooting with iPhones.