A great big telescope is indispensable for seeing faint deep-sky fuzzies. But on nights when you don't have the time or energy to set up a big telescope, it's handy to have a smaller scope you can quickly take outside for a short observing session. Here's how to choose a “grab-and-go” refractor to help you get the most out of every clear night.

The Basics

• The Telescope Mount. Some will disagree, but no telescope with equatorial mount qualifies as a grab-and-go. If you've only got 20 minutes, you don't want to spend time polar-aligning your telescope. So a grab-and-go telescope should have a simple and sturdy altazimuth mount.

• Telescope Tube. A good grab-and-go refractor has an aperture between 60 mm and 100 mm and focal ratio of f/8 or less. This keeps the length of the tube to 40-60 cm and the weight to 2-5 kg or so.

• Accessories. For a quick session, take along two eyepieces, one for low power and one for high-power views. And you can take a Barlow lens to double the power of each eyepiece. If you're looking at nebulae and you live under light-polluted skies, take an OIII filter. It's worth the effort.

A Deeper Look....