M64 has a very bright nucleus which easily highlights the prominent
dust lane (the obvious dark band).  The disk of M64 outside of the
nuclear regions, in contrast, is rather low surface brightness and
generally can't be seen with visual observation or even on some
photographs.  The image presented here corresponds approximately
to that situation since most of the disk is not visible.  The overall
angular size of M64 is 6 x 3 arcminutes.  Only the inner 2 arcminutes
have high surface brightness.