Yeah, that's an awkward size. You'll probably have to get a lens with a bigger thread (I've got a Raynox MX-3000PRO 58mm that's decent I got for about $120), then use an adapter ring to fit it to your camcorder. You might have to use two rings because 46mm is a bit of an unusual size, but you might be able to find one that will do it. Don't try getting a 37mm lens and fitting that on with adapter rings because you'll get a LOT of vignetting with that.