Seriously, I need help. I have technical questions that I [probably should be asking the manufacturer, but I thought it would be more fun to post it:
So I have my choices narrowed down to two 8" scopes. My first question is about the magnification - they are both listed as "480X, Highest useful magnification" but they both have different focal lengths and eyepieces. So question #1 is, how did the mfgr figure out that they both are 480 power?
Scope #1 Focal Length: 1000mm Eyeiece: 20mm
Scope #2 Focal Length: 2032mm Eyepiece: 25mm
OK - question #2: Which scope is better as far a viewing goes? Here are the differences (in addition to the above differences:
Scope #1 Angular FOV: 1 degree Linear FOV: 53 ft Focal Ratio: 4.92 Design: Newtonian Reflector
Scope #2 Angular FOV: 0.63 degree Linear FOV: 33 ft Focal Ratio: 10 Design: Shcmidt-Cassegrain
Do you have any astronomy group or club around where you live? Contacting them would be the best way to select/buy a telescope.
You must decide the purpose you want to use your telescope for. Here are a few questions.
What do you want to observe? Is it for planetary observation or for deep sky? How good is your location? Are you in an urban location or country side? The location matters because of your seeing conditions of your sky. How bad is the light pollution where you live?
The magnification (power, in your words) is not very important. Many planets are bright and so, higher magnification can be used for planetary observations. You need wide field of view or low magnification for observing deep sky objects. No matter which telescope choose you will want to have a wide range of eye pieces with you. You will choose your eye piece depending on the object you want to observe. Some of the deep sky objects are dim and if you use high magnification you will not see anything because the deep sky objects become too dim to see. For bright objects such as moon you can go for high magnification. In fact moon is too bright and you will need a ND (neutral density) filter.
A big word of caution - never NEVER look at Sun ever with any telescope no matter what magnification you use. Sun will instantly cause permanent damage even if you look at it for a extremely short moment. If you want to look at the sun you need special filters.
I would strongly suggest that you meet an experienced astronomer or join a club before you spend your money. You can also look for an on-line astronomy group who will guide you.
Ab3hn - I've learned a lot more since my original post, and what you say about FOV is consistent with what everyone else says in online forums. The other thing I have consistently read is that aperature is very important.
Also since my first post I've learned about another option that I am considering: an Orion 10" f/3.9 OTA, whick would leave me with the problem of picking out a mount/tripod on my own. The reason I call it a problem is because most online retailers aren't very good at listing a mount's weight rating.
Looks like this is going to be more difficult than I thought.
To answer your questions . . .
I live in a dark countyside area. I would eventually like to take astrophotos. I don't know of any nearby astronomy clubs, nor do I have a nearby retailer of telescopes (besides Sears, haha). And finally, I would like to look at plants, but my main insterest is DSOs. . . Out on a limb, I'm guessing that looking at planets can get old after a while.
So here's where I stand if anybody wants to throw in their two cents. I actually changed my mind on a couple things. I now have 3 Newtonians in mind:
1. Celestron's C8-NGT (Comes with Computerized GEM) 2. Celestron's C10-NGT ( " " " ) 3. Orion's 10" f/3.9 (No mount, recommend one if you can. Needs to support 45lbs from what I hear.)
PS - Regarding the mount, I'm not really crazy out the GOTO systems. I kind of want to learn how to star hop. If anyone knows of a heavy duty manual EQ mount, let me know.
Aperture is important but to understand it better you can read an article by Gary Seronik in Sky & Telescope March 2012 where Gary has analyzed the economics.
From your questions I am guessing that you are a beginner into astronomy. I am getting a strong feeling that you are going a bit too fast into this. A beginner could start of with nothing other than a sky chart, go out into the night sky and start identifying the objects, read as much as possible & understand more. Initially one can start with a pair of binoculars (8x50 or 10X50 are fine). One must have the ability to identify at least a few of the common stars, constellations. Straight away starting off with a telescope will be extremely frustrating. Navigating from star to star is a difficult skill that comes with a lot of practice combined with familiarity of the skies. You will not find any star of any object if you are on your own with a large aperture scope, no matter which type of mount it may have. Joining an experienced astronomer will immensely help.