The NP-101 4"/101mm Refractor Telescope from Tele Vue is a warp factor 10 in many respects. Large enough to be considered a serious deep sky instrument, yet small enough to be checked as luggage upon a commercial aircraft. A combination of focal length, aperture and field of view renders it great for terrestrial and sky viewing alike. Certainly costly, and well worth the investment for those devoted astronomers who know they'll enjoy the item for a lifetime.
From the dainty Tele Vue-60 to the flagship Tele Vue-NP127, Tele Vue employs a companywide philosophy consistent with their entire line of great telescopes & accessories. They produce brilliant optics in several sizes, none too big to use "on location", so you can have the best views capable of whatever aperture you can tolerate in price and weight.
The apochromatic refractor is the telescope design which produces the greatest breathtaking contrast and resolution, and Tele Vue offers these in six apertures. You won't get the light gathering capacity per dollar of Newtonian reflectors nor the portability for aperture of Schmidt-Cassegrain. But what you will get are views to be envied by both, with the darkest of background sky and the sharpest, widest fields imaginable. Combined with Tele Vue eyepieces, the experience cannot be bested by anything one would consider portable.