Astronomy Eyepieces

The purpose of an eyepiece to magnify the image, and several eyepieces can be used to give different magnifications and fields of view. You have to experiment with different, to see which is best for a particular application. For example, if you want to observe a large area of ??the sky, you need to get a low magnification and wide field of view.

Magnification

To calculate the magnification obtained by using a specialEyepiece, use the following formula:

Telescope focal length / eyepiece

For example, if the telescope has a focal length of 650 mm, such as the Sky-Watcher Explorer 130P, and use an eyepiece with a focal length of 10 mm, the resulting magnification:

650 / 10 = 65x

If you use a Barlow lens, see below, this increase can be doubled to 130 X, or tripled to 195x.

Barrel Size

Different barrel sizes are also available,that is, or 1.25 inches or 2 inches in diameter. Adapters are available for both, so that you designed a 1.25-inch eyepiece in a telescope for 2 inch eyepieces, and vice versa.

Focus

This is measured in millimeters, and the longer it is, the larger field of view, but the lower the magnification. Focal lengths are used for high magnification, while the long used to obtain a wide field of view.

Eye Relief

If you wearYou can provide glasses, the long eye relief. This means that your right eye against the eyepiece place to see something. The shorter the focal length, the shorter the eye relief.

Barlow

A Barlow lens is a special type of eyepiece, with the double or triple the magnification. And "used between the barrel and the eyepiece of the telescope.

How many eyepieces do I need?

InTo cover a range of magnifications of, say, 20x to 300x need, usually four or five eyepieces, plus a Barlow lens. And "go even better, for good quality eyepieces. If you buy the cheapest, you may find that you go out and buy new and expensive need it later.

Source: http://reference-astronomy.chailit.com/astronomy-eyepieces.html

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