In article , Chris Malcolm
wrote:

That's easy - Sigma lies. They pretend that you can take a single
pixel and split it up into three colors and have that be three pixels.

They don't lie. It's a different kind of sensor with sufficiently
different kinds of pixels and properties that the sensor megapixel

They lie.

When you measure the size of the image it produces you see that it is
4.6 mega pixels. That is the cold, hard fact. No amount of sophisty,
lies, or self-serving bull**** will alter that fact.

Of course it doesn't.

so you agree they lie.

But I was talking about the image implications
of that fact. People are using image MP as a measure of image
quality.

it's a major factor but it's not the only one.

Different kinds of image sensor technology buy you different
amounts of image quality for the same number of pixels. If you look at
the two different methods that have to be used in order to translate
from sensor pixels to image pixels from the two kinds of sensor
technology you'll see there is an inherent difference in luminance
resolution, and a larger difference in chrominance resolution.

the luminance resolution is about the same as another 4.6 megapixel
sensor (alias artifacts is not resolution, it's false detail) and the
eye can't see the extra chroma resolution.

however, the point is that the number of pixels is still 4.6 million,
no matter what kind of image the sensor produces.