Are the pixels on the receptors of higher resolution digital cameras smaller or is the receptor bigg

as the resolution goes up, what changes? we used to have 1.0 MB - now we have 6 or 8 MB --> I can't believe the the little receptor inside is 8 times as big.

To answer your question, the sensor stays the same size and the pixels shrink. The tile analogy provided above is the best example of this. With large scale integration it is possible to keep shrinking the physical size of a pixel to fit more on the same sized sensor. That kind of thing has been happening in computers for over twenty years too, the computer chip has tended to stay the same size while each year they pack still more electronic components on it.

But this magic doesn't come for free. Each pixel is a semiconductor element that is sensitive to light. Depending on the intensity of he light hitting the pixel it will generate an appropriate voltage, a higher one for intense light. That voltage is then translated into a digital value which eventually is integrated with all the others to form the digital image.

To accomplish that the makers place a very tiny lens on top of the semiconductor of each pixel to better focus the light. This is where things get murky. As the pixel gets smaller there are problems so does the little lens. As a result the pixel isn’t always as accurate as it could be when it was larger. Though as the pixel count goes up you do get a better quality picture, the quality lies in the detail, the crispness of the lines and stuff like that, but at the same time the image isn’t as crisp as it could be and often becomes less crisp as the pixel count increases on the same sized sensor.