Whats the dif? CCD vx Megapixel

[rick65000]

I notice that Megapixel is refernced as storage in product descriptions. But I read previously that at 7 megapixels digital photography surpasses film photography.

So my question is which is better
Optical Sensor Size 1/2.5, CCD with 4 megapixels (DiMAGE G400, Minolta)
or
1/1.8, CCD with 5 megapixels (DSC-P92 CyberShot, Sony)

I'm not really asking if Minolta is better than Sony or vice versa. I'm just asking about the various combinations of CCD size/number of megapixels that are offered. From what I've read I understand that the CCD numbers are inch measurements and (using the Minolta numbers above) may mean either 1 and 2.5 inch square (which sounds wierd) or 1 CCD at 2.5 inches. So is a .7 CCD difference greater than a 1 megapixel difference?

Thanks for any response.


Oh and here is an odd thought. If a digital camera focuses on a CCD can a drop in cartridge with a CCD and some miniture electronics that interface with existing SLR digital controls be made? That way old SLR bodies could remain useful after they quit making film, and all the film in the warehouses runs out, like is happening with 16mm.

(post was previously missing: y , and out)