Ken Rockwell today declared the sharpness of the D300, the D700 and the D3 to be equal and he has always raved about the color rendition of all Nikons. Would anyone be willing to reflect for a moment, for the benefit of those of us amongst the laity, what factors besides sharpness (and excluding lenses and post processing), are to be considered in choosing between DX and FX regarding IQ? If DX and FX are equally sharp is there a gain to be had in IQ by spending for the FX? Thank you.
Peter Van Dyken
Nice use of "laity". I've only heard used referring to parishioners, but you're correct.
Also, you've been warned now about *en %ockwell. $en @ockwell could post a real cure for cancer and people would still bash you if you praised him.
Finally, here's a short answer. And let's assume we're talking about the same number of pixels in either a larger or smaller space, with larger or smaller phostosites, respectively.
Smaller pixels may not be as sensitive to light as larger pixels. With larger photosites, because they are larger they catch more light more quickly. Think of putting a small bowl and a large bowl out in the rain. The large one collects more falling water more quickly, and can hold more water before it fills up.
The smaller the pixel the smaller number of photons it can hold before it fills up and spills over. That capacity is known as the photosite's "electron well." With the larger pixels/photosites that can hold more electrons you are going to have more dynamic range.
Moreover, given a certain amount of noise in a system, the larger pixels are going to suffer less. Let's say a small photosite holds 40,000 electrons, and a large photosite holds 100,000 electrons. Now this is an exaggerated number, but for the sake of making the point let's say you're going to get 1,000 electrons of noise per photosite. That means 2.5% of the data read off that site is going to be noise. With the larger photosite only 1% of the data is going to be noise. A much better ratio.
Now you know more than 99% of posters in camera forums. Once you can explain why diffraction limits the resolution of Nikon's current line of lenses and probably limits the number of photosites on a sensor in an FX body, you get bonus points.