I am often asked to recommend a telescope for someone new to astronomy. My answer is invariably, "Don't buy one, buy two -- mounted side by side." In other words, the best first telescope is a binocular.
7x50 or 10x50 binoculars are good general-purpose instruments which are excellent for astronomy, although even the most humble binocular will reveal a wealth of detail invisible to the naked eye. Larger binoculars will need to be mounted on a camera tripod and smaller ones give less bright images, although they can have the advantage of being extremely portable.
There are some things to consider when buying a binocular for astronomy:
You will find that there is a great deal of difference in price, even in binoculars of the same size. Get the best you can afford; they will tend to have fewer faults and give better images. However, the best thing to do is to try some out first. If your local astronomical society holds observing evenings/field meetings, go along and try as many binoculars as you can and solicit as much advice as you can. If you have friends with binoculars, see if any of them suit you.
This post by Marcie Greer to sci.astro.amateur is an excellent introduction to astronomical binoculars from the perspective of a newcomer to their purchase and use for astronomy:
From: Curtis & Marcie Greer <email@example.com> Newsgroups: sci.astro.amateur Subject: Binoculars a Great Way to Start (Long) Date: Tue, 08 Dec 1998 12:47:29 -0500 Organization: ICX Online, Inc. Message-ID: <366D6631.8A25D994@icx.net> While raking the leaves yesterday (I know...but better late than never), it occured to me that this might be a good time to share this with the newbie world. Dear astro newbie: Binoculars really are a great way to start observing! I didn't believe it either. I wanted a *real* telesope. I wanted to see *planets*, but I didn't have the $$ for a Decent Scope (DS). In fact, I had no idea what a decent scope was... had never looked through a real telescope (the little comet spotters don't count). Everywhere I read to buy binoculars, join a club, try other peoples DS's and save up for a DS. Knowing I would be disappointed, but also knowing that I would want binos anyway, I went ahead and bought binoculars. It was an excellent decision! I'm no expert in optics or binoculars, so I chose an independent shop that I knew specialized in quality stuff. You never know, but if you can find a shop with a Celestar 8" Deluxe on the floor, you might be in a good place for astronomical binoculars. Do not go to Service Merchandise or Sam's. You really need to be able to have them all lined up in front of you on the counter and try each one out. You need a salesperson who knows what is what and is willing to spend some time standing there while you futz around. Take your time... I have a hard time with this one. I get excited and rush things. I spent just over $200 altogether for binoculars, tripod adapter and cleaning supplies. I could have easily spent another $75 (at least) on a new tripod and I probably will when I have the $$. I am using a cheesey old tripod. It's flimsey and hard to adjust, but I had it already... If you can read up on binoculars for astronomy before hand, this is a good thing. There are several books available in most public libraries on binocular astronomy. I checked out two: The Binocular Stargazer by Peltier and Star Gazing Through Binoculars by Mensing. Mensing has a good chapter on testing your binoculars. I have found these books really useful, esp. since they concentrate on things that are pretty easy to find, and there's plenty of good stuff to see. Even newbies can shop fairly intelligently for binoculars. There are some basic things that you can look for. First, don't get the insta-focus. This is a flat bar on the top of the binos that is used to focus. Get the one that has a center focusing wheel. Insta-focus is good for birds, but not stars. You will want to take your time and get a finer focus for stars. Second, get coated optics. This is pretty easy to do. Be sure that the eyepiece *and* the objectives (big lenses) are coated. You can tell by holding them up and seeing if there is a greenish or golden sheen and they might say "fully coated" on them. Generally speaking, you will be looking for 7X50 or 10X50 binoculars. I tried out 7X50's and 10X50's and liked the 7X50's better because the field was wider. The ones I ended up with (Pentax PCF III's) had a 6.2 degree field. In other words, things weren't magnified as much, but I could see more. I figured that for my application, this was best and I am still happy with that decision. The wider field helps me get from star to star when locating some particular object I want to view. For instance, I was able to find the position for M1 even though it was a bit out from any major landmark stars. The wide field let me creep along from star pattern to star pattern until I found my target. Besides, more magnification won't make the stars any bigger. Only planets and NSO's can be effectively magnified. Generally, you need a DS for really good viewing of these things anyway. Once you decide about general things such as the focusing, a nice case, the cool rubber grips, the rubber eye cups that fold down (great if you wear glasses) and know which pair you want, have the clerk get the ones you are planning to buy out of the box. This is one mistake I made. I spent too much time looking at the demos and forgot to really inspect the actual purchase before leaving the store. Fortunately, it turned out OK, but it just as well might not have. Inspect the ones you plan to take home! Turn the lenses up and check to see that there are no scratches or white spots in the coating. Look for debris inside and bubbles in the lenses. Look through them at a distant straight line and be sure it stays straight to the edge of the field. Try out the wheels and knobs to be sure they turn smoothly. Hold the binos away from you, towards the light and see if the light beams coming out of the eyepieces are perfect circles with no rectangularity. How does the focus look through the center of the lenses and the edges? Also ask if you can return them and for how long and so on. After all you still haven't seen stars with them! Tip on using binoculars: move the two halves together until you see a single circular field; focus with the center wheel closing the right eye first then do the right eyepiece focusing with the left eye closed, then do both eyes open and make minor adjustments. One more test you can easily do (there are many!) is to take them outside at night (as soon as possible) and look at a nice bright star. When it is in good focus, the star should be a circular pinhole. There shouldn't be rays shooting out or other funny looking stuff. However, if you have astigmatism in your eyes and your glasses aren't right, you might see rays no matter how good the binos. I have to have my husband's good eyes do the star tests. Also, if you look at Jupiter (for example) it shouldn't look like a big florescent purple blob. Accessories: A decent camera tripod and a binocular adapter for it. I really like my Pentax adapter, but I will soon replace my cheesey old tripod. It is much improved since my husband tied a lead dumbell weight on a cable to the center. Some newer ones have a hook that you can hang a weight from. I find the tripod almost essential. If you have the money, there are some nifty mounts with a boom arm. These would be super!!! Care: don't rub the coatings off. Use a bulb blower (like an ear syringe or one for cameras with the brush taken off), microfiber cloth, and liquid cleaner/lens tissue as needed, in that order. Don't do any cleaning you don't have to. If it blows off don't wipe it. Keep fingers off the lenses then you won't have to clean up after them. Don't look at the sun. Don't poke your eye out. 8^) Read the manual.... A good book will give you more details and other tests, but this stuff you can do quite easily. Also, a good book will give you great ideas about projects for your nightly observing and even some lists. I have found that it is more fun after a while to have some goals rather than just ambling around looking at little lights in the sky. All of this is just my newbie opinion and experience. Apologies in advance for errors, omissions and wordiness... Hope this is of use to someone Marcie