Celestron Omni XLT 120 Refractor

Nearly five inches of unobstructed lens, which gives high-contrast planetary and lunar views and enough light grasp for the brighter deep-sky objects. Refractors of this size punch above their aperture on the Moon and planets because there is no central obstruction.

A metre of focal length gives 100x with a 10 mm eyepiece and reaches 200x with a 5 mm, which suits the planetary and double-star work this scope is best at. A 32 mm eyepiece still yields a usable 31x for clusters.

Moderately slow, which keeps colour error under control for an achromat and makes ordinary eyepieces perform well. There is still some violet fringing on the brightest objects, which is inherent to the two-element design.

A sealed doublet lens with enhanced coatings: nothing to collimate, minimal cooling, and consistent performance session after session. An ED or apochromatic doublet would remove the residual colour, at several times the price.

About 29 lb with the CG-4 mount and tripod, and the tube is long. Most people carry it out in two pieces, and the length means a solid setup surface matters.

A proper equatorial with slow-motion controls that tracks with one knob once polar aligned, and accepts motor drives later. It is adequate rather than generous for a metre-long tube, so let vibrations settle before judging the view.