how to make a refracting telescope?

Question

this will be my first telescope ,i don't know what should be the focal length of the objectiv. i want to make 50mm telescope or a little bigger like 70mm refracting telescope that would be sufficient to see jupiters moons and saturns ring and lunar craters. provide links

Answer 1

In its essence, a telescope is an instrument that makes a far away object look closer. To do this, a telescope has a device that collects light from a distant object (objective lens or primary mirror) and brings that light (image) to a focus where a second device (eyepiece lens) magnifies the image and brings it to your eye. To make a simple telescope at home, you will need the following:

two magnifying glasses - perhaps 1 - 1.5 inches (2.5-3 cm) diameter (it works best if one is larger than the other)
a cardboard tube - paper towel roll or gift-wrapping paper roll (it helps if it is long)
duct tape
scissors
a ruler, yard stick, or tape measure
sheet of printed paper - newspaper or magazine will do
To assemble your telescope, do the following:
Get the two magnifying glasses and a sheet of printed paper.
Hold one magnifying glass (the bigger one) between you and the paper. The image of the print will look blurry.
Place the second magnifying glass between your eye and the first magnifying glass.
Move the second glass forward or backward until the print comes into sharp focus. You will notice that the print appears larger and upside down.
Have a friend measure the distance between the two magnifying glasses and write the distance down.
Cut a slot in the cardboard tube near the front opening about an inch (2.5 cm) away. Do not cut all the way through the tube. The slot should be able to hold the large magnifying glass.
Cut a second slot in the tube the same distance from the first slot as your friend wrote down. This is where the second magnifying glass will go.
Place the two magnifying glasses in their slots (big one at front, little one at back) and tape them in with the duct tape
Leave about 0.5 - 1 inch (1 - 2 cm) of tube behind the small magnifying glass and cut off any excess tube remaining.
Check to see that it works by looking at the printed page. You may have to play slightly to get the exact distances between the two glasses right so that the image comes to a focus.
You have just built a simple refracting telescope! With your telescope, you should be able to see the moon and some star clusters as well as terrestrial objects (i.e. birds).

http://science.howstuffworks.com/question568.htm

http://spikesworld.spike-jamie.com/science/astronomy/c421-01.html

Answer 2

You certainly Can make your own telescope, and yes a book is the best way to learn the techniques, not yahoo answers...See Note below*

But re: you question of focal length. For planetary objects like you mentioned, a longer focal lenth/ratio will be better for you, and easier to make. Shorter focal lengths provide lesser magnification and are also more prone to "chromatic abberation"<
Focal Ratio is the length of the total light path length from the main lens to eyepiece) Divided by the Diameter of the main lense. You want 10:1 - 15:1 for planetary viewing. So if you get a 50MM lens, you should get one that is at Least 500 MM focal length, preferably though 750MM or even longer.

And...Very important:

*Note: if you want to CLEARLY see planets, Saturn's rings, and craters...and you DO because they are Very cool...DO NOT use a magnifying glass for your main lense. You will have to purchase a 2 or 3 element Optical quality lense, or you will only see blurry images, huge color shifting, and cruddy detail.

Good luck and Dark Skies!!!

Answer 3

If you realy want to enjoy the sky, buy a ready made one.

Unless you would rather enjoy making the telescope for yourself then enjoying the sky.

Surface finishes are extremely important. Quality of lens and the mechanism to focus are all very critical to observe a moving comet......... and the other moving objects in the sky.

Answer 4

There are many resources at your disposal. You might want to visit the sites below, as well as check local astronomy clubs for telescope making workshops.

www.atmsite.org
www.atm-workshop.com
www.stellafane.com
http://www.starastronomy.org/TelescopeMaking/Links/

Answer 5

PRICE, no color correction required with a mirror, much larger aperture possible with a mirror (light gathering), more complex mount required for a refractor. A 6 inch triplet APO refractor can cost THOUSANDS of dollars.

Answer 6

try doing so by referring a book.
instructing you throug web may create misunderstandings
a book will provide you a best explanation
i don't know any links related to it
sorry

Answer 7

Just google it out friend

Answer 8

Jus' check out som ref. bks mann!!!