my telescope

[nebs]

i received a telescope for my birthday because i've always been interested in astronomy and wanted a telescope of my own. however, when i take it out to hunt for things in the sky, everything seems just a little more magnified than when observing with a naked eye, but im sure this is a more powerful telescope. so my question is, what kind of a magnification is it capable of, and what can i use it for (please use the photo provided and following data for your answers):<br /><br />the scope is a "celestron firstscope 80 eq refractor" with these specifications:<br />- aperture: 80mm<br />- focal length: 900mm<br />- focal ratio: f/11<br />- mounting: german equatorial<br />- tripod: adjustable aluminium<br />- rack and pinion focuser (whatever this means!): 1 1/4"<br /><br /><br />any ideas??<br />cheers, <br />nebs

 

[nevers]

Hi Nebs - <br /><br />Welcome to SDC! Generally speaking, you get about 50x per square inch of aperture. This means the highest your 'scope would normally pull is about 150x. It will go higher of course but you will not be able to focus clearly on objects.<br /><br />Your 'scope will do very nicely on the moon. You should be able to see the banding on Jupiter and the Rings on Saturn. I'm not sure if you would be able to seperate the different divisions or not: maybe on a night of really good seeing. An 80mm 'scope is not that much aperture and it has an f/ration of 11. This may hinder you some on the larger Open Clusters. I would stick mainly with the Messier Objects although the galaxies will be visible in dark skies, they will look like very faint foggy-like objects. Globulars will look nice but I don't think you'll be able to resolve individual stars within the Clusters themselves. One thing that you can certainly see will be double stars. I think most people pass up these objects but I do a lot of "hunting" from Urban skies and double stars are something that I can see from my house (even with a 16" 'scope some things are just not visible from Las Vegas) plus they are a challenge, they're pretty (different colors) and hunting them will help you learn the sky.<br /><br />Your 'scope is a beginner 'scope for sure. The Rack and Pinion is the name for the design of the focuser. The other is Crayford. Some eyepieces are 1 1/2" in diameter while others are 2". Your focuser will only accept 1 1/2" eyepieces. Not a big deal at this stage.<br /><br />Aperture = the size of the lense.<br />Focal Length = the distance from the lense to the eyepiece.<br />Focal Ratio = Some scientific mumbo jumbo that I don't really understand fully. Baiscally what I've found is 'scopes with f ratios of 5 or 6 can see a wider path of the sky. 'Scopes like yours have a more narrow view.<br /><br />German Equatorial (GEM) = The design of the part that sits between the tripod and the telescope itself. GEM

 

[bbrock]

Nebs<br /><br />Not to panic. I haven't seen the picture yet because it hasn't been approved yet for viewing. However, your Celestron Firstscope takes 1 1/4" eye pieces and is german equatorial mounted. This isn't a toy telescope. You didn't indicate the focal length of the Eye Piece ( EP ). <br /><br />Telescopes have interchangable EP's. The magnification is equal to the telescope focal length ( 900mm ) devided by the EP focal length. For example, a 90mm EP would give a magnification of 900/90 = 10x. A 9mm EP would give 900/9 = 100x. If you look on the eye piece it should have the EP focal length printed on it. <br /><br />Now to answer your question. Your telescope is an 80mm ( 3.17 inch ) aperture scope. A good rule of thumb is that the maximum usable magnification for any scope is 50 times the aperture in inches. This means you should be able to use magnifications up to 3.17 x 50 = 158x. The best viewing will likely be between 80x to 120x. <br /><br />I don't know if your telescope came with only one EP or several. But I would look in the box for EP's with focal lengths from 6mm to 25mm. This will give a range of magnification from 150x down to 36x. You can go lower in magnification, but I wouldn't try to go higher. <br /><br />One last thing. Because your scope uses 1 1/4" EP's, you have available many dealers that sell EP's that will fit your scope. However, before you do, post a question on this site about which ones to purchase. <br /><br />Best of Luck<br />Bill<br />

 

[heyo]

Try this.<br /><br />I am not sure where in world you live, but I live on the US East coast, so this may or may not apply to you the same as it does me.<br /><br />Around 9PM or so this next few weeks, look in the Eastern sky roughly about 35 degrees up (that's a rough estimate off the top of my head from my own viewing the past few nights, but pretty close to due East) you should see a bright star, brighter than most stars around it and a bit more yellow tinted. It stands out as one of the brighter stars so you should find it fairly easily.<br /><br />That is Saturn, point your telescope at that and focus it in, and that should give you a pretty good idea of the power of your scope. You should see the rings and maybe the larger moons.<br /><br />Jupiter will be out too, same area of the sky, hours later, I haven't viewed Jupiter yet this year, because I think it comes over the trees and houses near my about 3 AM but it will get earlier and early in Feb and March.<br /><br />Heyo

 

[nevers]

The picture hadn't been approved when I wrote my reply. So, forget about the "red-dot" finder: I see you already have that. Try for a 6 x 30 finderscope instead. It'll really help you out better if you decide to try for doubles and the brighter Messier Objects. If you learn how to Polar Align your 'scope, the RA & Dec slo-mo knobs will work a lot better when tracking an object. Also, your 'scope will accept certain battery operated tracking motors.<br /><br />After looking at the picture I see one more thing that is really, really good: That would be that your Lense Cap has a built-in Aperture Mask. When you look at Jupiter and Saturn you will notice a "purple haze" around the planets (and brighter stars too). If you put the lense cap on but remove the little cap on the very end, you will notice the purple color almost disappears. This purple color is normal for your 'scope. By looking at objects through this small opening, you will lose the purple fringing but you will also lose half the amount of light coming into the end of the 'scope. It's a toss-up but I'd rather lose the purple color. You can also invest in a Minus Violet Filter.<br /><br />Bill is right - this 'scope is no toy. Use it well and have fun!

 

[nebs]

thanx, i really appreciate everyone's advice. i should have mentioned that i'm based in melbourne, australia and im also a member of our astronomical society, so i receive a yearbook with all the important dates and objects for viewing. as for the eyepieces, i received two in the box. one says 10 and the other 20. but i will go and buy some more eyepieces, and other gadgets soon.<br /><br />thanx again,<br />nebs

 

[nevers]

Hi Nebs - <br /><br />You realize that we are all drooling about your location! Thanks a lot. <img src="/images/icons/wink.gif" /> Before EP's, think about a Barlow lense. And I think I can speak for the others here: you'll have to report back every so often and keep us informed of your adventures.