Thanks. So if the spotter has adjustable magnifications then the eyepiece doesn't need to be adjustable? Let's see, is this forthcoming thought process correct? If you have a 20 x 60 adjustable magnification spotter, with an attached BTX, the spotter magnifies an additional 35x more no matter what magnification the spotter is on, thus eliminating the need for an adjustable BTX eyepiece?? Something like 20x60x35 (with BTX)x85mm objective lens?