PART II: TELESCOPES AND BINOCULARS
A: TOOLS OF THE TRADE (THE EQUIPMENT)
TYPES OF SCOPES - REFRACTORS
Though it's difficult to exceed the thrill of looking at a dark
night sky with just the naked eye (and there are some things, like meteors
and aurorae that are best viewed this way), even a modest optical aid
can show thousands of times more stars and hundreds of objects invisible
to the naked eye. This makes the sky an exciting place--full of wonderful
things to find.
Binoculars are the easiest to use optical instruments, and offer the
advantage of a completely correct image, which makes their use on land
and sea practical while still being appropriate for stargazing and Moon
viewing. While binoculars of 40mm and larger are appropriate for nighttime
viewing, daytime viewing can be done with binoculars small enough to put
in a shirt pocket. Scope City has a huge selection of binoculars for every
use—all the way up to big giants that require heavy-duty mounts
to support them.
Refractors are often the preferred telescope type for use in the daytime,
and their advantages make them a superlative choice for nighttime viewing
of the Moon, planets, or stars. This is the type of telescope you probably
have a mental image of when someone says "telescope". It has a lens at
the front, and an eyepiece in a focuser at the back.
It comes in a land/sea use configuration called a "spotting scope" (the
image is correct, both up and down and left-to-right) or a longer, larger
version on a heavier mount, usually referred to as an "astronomical refractor"
(the image is correct up and down, but reversed left to right). The images
produced have terrific sharpness and contrast, and are typically constructed
very sturdily to take a lot of abuse. This is the type of telescope you
can give to children, and keep all your life. Very big ones are very expensive,
but the smaller, more portable, sizes are quite affordable. Appropriate
sizes for land and sea use vary from 50 to 90mm, while astronomically-oriented
refractors are usually from 60 to 150mm in diameter. The largest refractor
in the world has a lens over 1000mm across (40"), but today, refractors
larger than 150-200mm (6" to 8") are not considered practical due to their
sizes and weights.