Film was realtively easy to understand. You have little grains of silver salts, they get exposed to light. You develop them and they turn bigger and blacker, and make up the light and dark areas of your photograph. The finer the grain, the more detail in the photo, and the smoother and richer the transitions.
Pixels, on the other hand, are remarkably complex electronic light-sensitive receptors. They’re often compared to little buckets that collect light, but they act more like small faucets that let a charge through, depending on how much light is hitting them. Take a look at the video for more elaboration, but suffice to say, there’s a whole lot going on in that little square of real estate, measured in microns.
You might assume, and it’s been claimed, that a bigger pixel has less ability to resolve detail. Hey, the “grain” is bigger, right? Well, that’s not really the case. It also has been said that more pixels don't equate to better image quality, because the pixels are smaller. Smaller pixels are not as good with respect to bit-depth and handling noise, either. Some processors use the smaller, noisier pixels to get more samples, and effectively process the base noise out, and then some. The bottom line is, you have to look at the files, and that’s what we’re doing here.
The larger pixels, the bigger sensor, and the higher pixel count of the Hasselblad H3DII-31 certainly gives us some incredible detail, but not without the tradeoffs of a slower shooting speed, lower ISO capabilities, and no Live View or video capability. What we’re seeing here, in the DSLR shots from the Nikon D3s and Canon 5D Mark II, are some very competitive results from smaller sensors, smaller pixels, and different processing technology.