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[Chicago Astronomer - Astro Joe]

I came across this link while perusing other astro boards, and found it quite entertaining. For our advanced members, it may be old news, but I got some things out of it.

www.wwnorton.com/astro21/sandt/usingscopes.html

[stargazer]

Hi Joe,

I have some info on scopes I will post in here as well. Its on buying a scope. Very interesting


B

[ripps1]

One point I didn't see in the article was the reminder to continue breathing while at the eyepiece.

Most of us actually hold our breath in the effort to squeeze photons out of our target (yours truly included). A little of this goes a long way to begin to starve our optic biosystem of oxygen. Capable eyesite requires a good supply of oxygen to perform at its' maximum. Some have reportedly gone as far as to breathe pure O2 while at the scope (I think the results are still out on this one, though).

Remember, relax and keep breathing. -Rip

[Chicago Astronomer - Astro Joe]

My eyepiece querks:

• Sometimes the eyepiece gets clouded by my body heat or breath - developed interesting side of mouth breathing techniques
• Pretty Women who often deposit mascara on the surface
• External glare interfering with observations - (I have added rubber eyecups to cut down the light)
• Old eyepieces from decades ago scratched up...I just don't have the heart to toss
• Age tremendously while my favorite eyepiece is 1/2 a second away from impacting on the concrete from careless handling
• Barlows that greatly diminish FOV brightness
• Losing my target when upping the magnification
• Happy to make use of my very old .096 eyepieces with film canister adapters
• Forgetting at times to tighten down the hold down screw, and have the eyepiece slip out - (See concrete)
• Astronomically challenged individuals who refer to the eyepiece as the "lense" ;D
• Attempting to use the "Averted seeing" technique and sometimes getting nothing

And.................loving it.

[stargazer]

Here is some info fr buying your first telescope. I hope it is Helpful to members who are thinking about buying one.

I get asked this question as soon as people find out that I'm into astronomy and telescopes. It is fun for me to help folks to answer this. Often I find that what kind of telescope people think they want and what they really want are two very different things. So, to start, I ask people two questions that need to be looked at together...

What do you really want to do with a telescope?
How much money do you have to spend?
Many times after asking these questions I find out that what someone really wants is a fancy living room decoration and not so much a good star gazing instrument. How can you tell? Well if someone says they want to spend less then $250, I will usually come back with two answers 1) Get a good pair of binoculars. 2) Get a Dobsonian. What happens to tip me off is that their nose sort of scrunches up at these suggestions and they go out and buy a cheap Newtonian or Refractor with the cool looking (but cheap) mount and flimsy tripod. It looks good in the living room window but is so frustrating to use that it stays there. Instead of taking some time and looking seriously, they run off to the local mall or XYZ-mart and buy the $149 650x special. So if you are looking into buying a telescope here is some advice for you...

Choosing a Telescope: The Basics

However, for those that have at least a mild interest in astronomy, who actually want to look up and "see the stars" and are not looking for a fancy living room decoration here are some basic rules of thumb...

START WITH BINOCULARS
If you do not have much money (say not more then $250) you may be happiest with a good pair of binoculars. Binoculars, even inexpensive ones, will amaze you with how much you can see of the night sky. I viewed the sky far more often with my cheap ($98) 10x50 binoculars then my 10" telescope.

DO NOT BUY A TELESCOPE BASED ON POWER!!!
If a telescope has "650x" (or any other reference to power) prominently displayed on the side of the box, walk away. Even the best telescopes are limited to about 50x-75x per inch (25.4mm) of aperture. For an inexpensive 60mm refractor this equals 120x. So "650x" is just a marketing ploy to get you buy their inexpensive scope. Do not buy a telescope based on its power. Do not buy a telescope based on its power. Do not buy a telescope based on its power.

APERTURE IS KING
The diameter of the lens or mirror is generally the most important attribute (but not the only one) to consider in a telescope. Generally one will be happiest if they buy as much aperture as can be had in their price range. Large aperture refractors (lens based) can be very expensive. That means that most of us will be looking at a mirror based telescope.

SOLID MOUNT
One can have the best optics in the world, but if the mount is wobbly, shaky, hard to use, or hard to track the sky with, you will NOT be happy. A good combination of aperture and solid, easy to use mount is a Dobsonian. Those department store telescopes almost always have poor mounts.

USED TELESCOPES
Often, if you do not need to have the latest gee-wiz scope (and sometimes if you do), you can save a lot of money by buying a used telescope (This is what I did). Older model telescopes are often available on the used market for less then half of the cost of a new telescope. Serious used telescopes are almost always in excellent condition as the owners take very good care of them. See the links at the end of the page for online used telescope classified ads that I have used in the past.

KNOW WHAT TO EXPECT
The views through your telescope simply will NOT match what you see in astrophotos in magazines or even on the box of your scope. Period! First, you will not see nebulae in color, planets will look tinier then you expect and will lack most of the color and contrast you see in books and magazines. Most people that look through a telescope for the first time are somewhat disappointed about what they see, or what they don't see. Don't get me wrong, you will never forget the first time you see Saturn or the Moon in a telescope and the "Wow!" that escapes your lips will amaze you also, but the "faint fuzzy" stuff often disappoints first time viewers.


This is Part one.

[stargazer]

Part Two


What Telescope is Best for Me?

Answer: A telescope that you will continue to use and enjoy, NOT a device that will frustrate you to the point of never wanting to use it again. Really though, the answer depends on what your goals are and the money that you have to spend. Good telescopes are expensive regardless of the type. Now, I am going to assume that you know the difference between a refractor and a reflector and their variants. If not, click here and a new window will open that shows the difference.

The first thing you must do is answer this question: WHAT DO I WANT TO DO WITH MY TELESCOPE?

I DON'T KNOW WHAT I WANT.
This is simple, get a good pair of binoculars and a star chart. You will be amazed at just how much there is to see through a good pair of binoculars. Generally a 7x50 is a good start, a 8 x 56 or a 9x63 is the next step up for a pair of "astro" binoculars. Notice, that if you take the second number (the size of the main lens in millimeters) and divide it by the first number (the power) you will get what is known as the "exit pupil" in millimeters ( 56mm / 8=7mm ). For an "astro" binocular an exit pupil value of around 7mm is ideal, this is the size of an average night adapted pupil. (Exit Pupil is NOT the diameter of the eyepiece lens' of a pair of binoculars). If you are a bit older then an exit pupil of 5mm may be better. In any case, a magnification (power) value over 10x makes hand holding very hard as the natural shaking that hand holding introduces is magnified as well. Magnification over 10x will require a tripod mount or an expensive image stabilizer system.

WHAT I WANT IS A COOL LOOKING SCOPE FOR THE WINDOW SO I CAN IMPRESS MY NEIGHBORS...
This is fun. First, Be honest with yourself! If what you really want fits in this category, the people that you likely wish to impress will not know the difference between a good telescope and a 650x XYZ mart special, so you can save a a lot of money :-). I would get a 70mm refractor with the cool looking German Equatorial Mount (GEM). That would make it a little bigger then your neighbors 60mm scope and it would have a cooler mount to boot. Also a refractor looks like a stereotypical telescope, unlike a Newtonian which will just confuse them ("which end do you look through"). If you need a little telescope for your office or a shelf Orion sells a little tiny brass refractor that would just fit the bill. If you intend to spy on your neighbors (I do not recommended this) then an "alt-az" mount would work better then a GEM, but you will want a 45° diagonal.

I HAVE A MILD INTEREST IN STARGAZING.
See "I don't know" above. For you binoculars are still the best way to start. But you really think that a telescope is for you, I would have to recommend a Dobsonian. You are the best person to determine what size to get but a nice average size would be a 6" to 8". Dobsonian refers to a Newtonian in a simple "alt-az" cradle type mount. This is best way to maximize your aperture per money spent. A "dob" is easy to use and setup.

I WANT A GOOD TELESCOPE AND HAVE $XXX TO SPEND.
Less then $200
Getting a telescope in this price that will not disappoint you is very very unlikely to happen! I must strongly suggest that you buy a good pair of binoculars. Orion sells very nice binoculars in the $150 dollar range. In the same way that it is suggested to avoid cheap telescopes, It is best to avoid cheap binoculars ( less then $80 - $90).

$200 - $400
You just might find a usable telescope in this range. Some examples would be dodsonians sold by Orion and others, as well as some of the smaller Meade ETX models. I have some personal experience with the Meade ETX-70 model and I can actually recommend it for many people. The ETX-70 has a secret to its success... With the supplied eyepieces, it doesn't have much more power then a pair of binoculars. This was a wise move on the part of Meade.

$400 - $800
There are many choices in this range. There have been very good reports about Stellarvue telescopes. Medium sized Dobsonians (8" - 12") can be had in this range as can some of the more advanced Meade ETX models (I have one of these...). Also the Meade LXD55 series of telescopes have surprised many people with the amount of scope you get for the amount of money – seems that they are worthy of consideration.

More then $800
See the next topics...

I WANT TO DO SOME SERIOUS STARGAZING.
Here is where the number of choices explode! Money becomes more of a limiting factor then the choices available. The simple fact of the matter is that those with lower budgets will need to look at binoculars or Dobsonians. Those with more money will need to consider the size and portability of the telescope of thier dreams. Big telescopes are, well, BIG! They can be so big that they will not fit inside the average car. The choices start with larger "dobs" in the 10" and larger range. Many, many, many very serious stargazers use large (12.5" to >20") dobsonians. We then move over into scopes like Schmidt-Cassegrain Telescopes (SCT) and APO refractors. Finally we add computerized "Go-To" capabilities to these bigger APO's and SCT's. These larger and/or more complex telescopes can take a lot of room and a lot of setup time. If you are like me, you work a normal shift. If the sun sets at 9PM that means that it doesn't get dark until 10 PM or later. If you want to go to bed at midnight and the scope takes an hour to disassemble and put away... Hmmm... You do the math. There is something to be said for getting a simpler telescope.

I WANT TO GET INTO ASTROPHOTOGRAPHY.
First take a look at the Astrophotography for Beginners page. For the sake of this point I will assume that we are talking about long exposure astrophotography. Here the most important thing is not necessarily the telescope but rather the mount. A very high quality mount is a must. Often, quality German Equatorial Mounts (GEM’s) are preferred by astrophotographers. Mounts such as those made by Losmandy, Mountain Instruments, and Astro-Physics are employed by many astrophotographers. These GEM's also have the advantage of being able to accommodate many different types of telescopes. The very capable Meade and Celestron fork mounts work well but you must also use the scope that came with the mount (although you can piggyback another scope on it). Another option may be the Meade LXD55 series of telescopes.

I WANT A GOOD SCOPE FOR VIEWING THE PLANETS (Mars, Jupiter, Saturn and the Moon).
Good planetary telescopes have a couple things in common. Contrast and usually a long focal length. Many people feel that the best planetary telescopes are APO refractors. The problem is that any APO refractor is going to be expensive. Lower cost options can include Maksutov-Cassegrains and “long” achromatic refractors. Schmidt-Cassegrain Telescopes (SCT) can also offer pleasing views of the planets. It is still true that a larger aperture has a higher resolution then a smaller aperture, but you MUST have very steady air to take advantage of it. So, for viewing planets, a larger aperture is not as beneficial as it is for viewing deep sky objects.

The Conclusion...

A telescope can be a great thing, or it can discourage you from enjoying a rewarding hobby. The choice is yours. I cannot emphasize enough... DO NOT BUY A CHEAP TELESCOPE!!! If you can get a great deal on a good scope, great, but you WILL waste your money if you get that $149 650x special that may be tempting you. Never even consider a telescope that advertises it power on the box (650x, 725x, 625x60, etc). Why? Well put simply, I have never seen a good telescope that advertises it power on the box

I hope you enjoy reading it as it is very informative. I tried to put this all together but I was told it was to long. I took this from my site thats why I couldnt put in a link for you to read.


B

[NatureDevil]

.....wow..............

.......wow..................

.........that was really good........

....I am trying to convince an older gentlman at work to sell me his old scope that he bought over 30 years ago, and I have no idea what I'll be able to see with it, but whatever it can see, I'll look at. I need to play with a scope for a while and get used to using one. I also am in the market for a brand new pair of binocs, but that may not be till next month. My phoneline has been shut off, so Brian has to deal with a few things first.

Oh, I apologize for occassionally slipping into the 3rd person. I do that sometimes if it usually involves bad luck or misfortune for myself. Tries to give me a new perspective in things.

NatureDevil

[stargazer]

Brian,

Good luck on trying to get that scope. Please let us know if you do. What size bino's are you looking at.


B