Actual detail is, as it sounds, just how much of something you can see in your image. You know it when you see it: the pores of skin, the individual eyelashes, the reflections in water, etc. When they are not there, our eyes can fill it in (or dismiss it), so we still understand the image, but that mental act of filling in is just not quite as satisfying as actually seeing it. Many things can keep your image from having actual detail. Focus and depth of field are ways we un-detail something on purpose. This helps separate one element of your photo from another. But for the purpose of this discussion, we’ll assume this is about the detail in the part of the image you are focused on, as that is the part that gets people to say, “so sharp, brah!” And any camera with a decent sensor and good lens has the ability to produce that impressive level of detail. The kind where you seem to be able to zoom into an eyeball forever and still see an impressive amount of information
