Expert: Philip Stahl - 3/24/2007

Question
I am very new at this whole thing but also very interested in it at the same time. The problem is that I dont even know where to start. I just got a Tasco Novice not long ago. It says D=60mm F=700mm coated optics. So what does this mean, How far, and how well will I be able to see?  Also how exactly do you know where to look in the sky to find what. Its all very confusing but please help me out here. I'd really love to look at some planets or stars or any thing to be honest. Thank you very much.

Answer
Hello,

Astronomy is a fascinating field, but it often takes a lot of effort, work to get into the use of its instruments. And using them to their maximum potential presumes you have a good knowledge of the sky. Alas, this cannot be communicated simply via message boards and forums such as this. You need actual, hands on experience.

I suggest first, checking to see if there is a local astronomy club in your area, that you can join. They will usually feature special members' nights, or workshops for members that include familiarization with your locally visible sky objects. They will also show you how to use the teslescope to best advantage.

Failing that, check to see if there is a nearby community college that features basic astronomy courses. They will also have facilities to show "newbies" the ropes, and how to find sky obejcts. Most such courses can be "audited" - meaning you don't have to take them for grades or credit.

Failing that too, you are left to master it all on your own. It isn't easy but not impossible either. My wife did it using only a "Colliers' Encyclopedia" and a telescope she borrowed from a local observatory. She waded through star map after star map, and learned her way around the sky - until she knew it better than most experts in 6 months.

A lot of resources for your journey are available at Edmnd Scientific Co. For example, check out the link:

http://scientificsonline.com/category.asp?c=421182&sid=edsci&cm_mmc=edsci-_-link...

You will see available here an "Edmund Star and Planet Locator" which is an extemely useful device!

Also, I'd go to the link:

http://scientificsonline.com/category.asp_Q_pc_E_421182_A_c_E_421198

and get any books you think may help, go through the pages and look especially for:  "How to Use Your Telescope"

This is an absolute essential if you hope to get the most out of your instrument.

The numbers on your scope refer to:

Focal length F  = 700mm

Diameter D (of objective or lens) = 60 mm

"D" will basically indicate to you how much power you can get out of your scope that is *useable* Since one usually uses no more than 50 x per 25 mm, this means your maximum power will be:

(60 mm/ 25 mm)  x   50  =  120

So, a magnification or power of 120 is the maximum you can use.

Now, you will also likely have *eyepieces* that are labelled, say like "25mm". This is the focal length (f) of the eye piece.

To get the magnification for a particular *eyepiece* you divide the focal length of the telescope objective (F) by the focal length of the eyepiece (f).

Magn. =   F/ f     =   700 mm/ 25 mm = 28 power

Thus for a 25 mm fl eyepiece, you obtain about 28 power.

If you have an f = 12.5 mm eyepiece, then that will obviously be double the original power, or 56 x.

Final word, if you are on your own - go for it! Don't hold back - but just obtain the resources you need and learn your sky one constellation at a time. Meanwhile, during that learning period, just take your scope out and learn how to use it, starting out with easily visible objects (Moon, bright stars etc.) and moving on to more difficult ones.

Good luck! The main thing is don't be afraid to learn on your own! It can be done, and millions have already succeeded!