anw, gotten the 50-200 samsung lens to complement the 15-55 1st... not a wonderful lens but good enough for me a newbie to practise and polish up my skills...Hopefully, by then there are more compatible lens available..
Nikon mount has both options, electronic or mechanical. Older lenses (those with aperture ring) have aperture lever, newer (G series, no aperture ring) only have electronic coupling.