
Originally Posted by
onherblackwings
good day sir
in-body focus motor means that your camera body is the one responsible for rotating the lens to keep your subject in focus.
nikon's entry-level cameras (D40, D40x, D60, D5000 and D3000) does not have in-body motor, hence, they cannot rotate certain types of lens.
lenses marked AF-S and AF-I are the only ones that can auto-focus on the cameras listed above because they have motor built inside the lens.
if you buy a camera as kit, it usually comes with an AF-S lens.
if you buy a camera body only, make sure you get an AF-S lens. (AF-I lenses are a bit expensiive)
hope this helps.