Published online by Cambridge University Press: 06 December 2010
Telescopes in the 3- to 5-inch aperture range can be divided into three wildly diverse groups. On one hand, we have an overabundance of small instruments that are marketed toward unsuspecting newcomers to the hobby. These are often sold through department stores, consumer-club warehouses, toy stores, hobby shops, online auctions, and other mass-market outlets like television shopping networks. Two underlying traits are shared by the vast majority of these instruments: mediocre optical quality and shaky mounts.
On the other hand, we have some nice, middle-of-the-road economy instruments that serve their owners well. These instruments excel as grab-and-go telescopes, allowing their users to spring outside at a moment's notice without the burden of carrying massive mountings and huge tube assemblies.
Finally, we have some of the finest instruments sold today. Small-aperture refractors from well-known companies like Tele Vue, Takahashi, and Astro-Physics delight and entertain amateurs who are looking for the highest-quality optics, top-notch mechanics, and superior portability. They share the same spur-of-the-moment freedom as the middle group, while delivering top-notch images.
Giant binoculars, defined here as anything 70 mm or greater in aperture and 10× or more magnification, are also included in this chapter's mix. Owing to their lower magnifications, some of the challenges here are beyond their capability, while others are made to order.
Regardless of which instrument you are using, the challenge objects gathered here will test its limits, and yours.