# Thread: New and Excited!! :)

1. ## New and Excited!! :)

Hello!!
My name is Charley, very novice astronomer!!

My girlfriend and I decided to use some of our tax return on a new hobby that we can share, and bought us a telescope!!!

We did a little research and purchased a tabletop Orion Starmax 90mm. It came with a 10mm and 25mm lens. In our kit we also received a Zoom! lens that can go from 7.6mm - 21.4mm. And, a 2x Barlow lens.

Of course, we started with the moon! (last night) Tonight, I was able to use our max magnification on the moon (7.6mm with the 2x Barlow).
I was able to see Jupiter, the 2 red stripes on it and 4 of its moon!!! I did get some focus on Mars, but I didn't have the time (or energy) to get our max focus on it.

Anyways, I decided to post here because I was wondering what objects we should focus our attention on besides the ones that I mentioned. I can see how this hobby can be addicting! I'm already wanting to purchase a 5x Barlow lens. That brings me to my next question. What should my next upgrade be in terms of lens?

Thanks!!

2. ## Re: New and Excited!! :)

Skip the 5x barlow. You won't be happy with that.

You have a 1250mm f/13.9 "Maksutov Cassegrain" telescope. Telescopes have some practical limits to magnification. You can always put on eyepieces with more magnification or use barrows... but when you exceed the maximum practical magnification the image you see will become very blurry... it'll be bigger, but you won't be able to see any detail.

To calculate the magnification of the scope with a specific eyepiece, you divide the focal length of the scope (in your case 1250mm) by the focal length of the eyepiece (for example if you use the 25mm eyepiece then it's 1250 ÷ 25 = 50. So that's 50x magnification.

There are two limits for a scope. The general guideline is that you can "in theory" (notice the quotes) take the diameter of the telescope in millimeters and double it. You've got a 90mm scope so that works out to 180x power.

HOWEVER (notice I typed in all caps... that was deliberate) this "in theory" magnification requires exceptionally good "seeing" conditions. There are some places on the planet where good seeing conditions are fairly common -- but this is rare. So for MOST people, the best you can hope for is about half that limit. In other words... about 90x is usually the best you'll get and if you push beyond that you'll start to notice the image doesn't focus nearly as sharp. The more you push it, the more the image quality degrades.

It turns out the focal ratio of your scope is a good guideline to the shortest focal length you should use for an eyepiece. If you were to use a 14mm eyepiece (since you have an f/13.9 scope so I'm rounding to 14) then 1250 ÷ 14 = 89x.

This means you'll generally be satisfied with the sharpness of the 25mm but you may find the 10mm is pushing it. The zoom eyepiece will work best above 14mm focal lengths.

This is a "guideline" and not a rule. Some nights you may get lucky. But you can't count on that. Most nights you'll probably want to be a bit more conservative with the focal lengths.

3. ## Re: New and Excited!! :)

While small in aperture, those have a nice focal length, depending on your viewing conditions / light pollution I'd give try on globular clusters see A guide to globular clusters, saturn of course, and if conditions favor you, go for the brighter PN's, and you should totally get a full aperture solar filter on it (should be rather cheap for a 90mm somewhere around \$40 USD)

4. ## Re: New and Excited!! :)

Early in the evening, check out the Orion Nebula (Messier 42). This is in the "sword" region of the constellation Orion and a very easy deep-space target (one of the easiest).

Orion is a winter constellation. As it's spring, Orion is up in the early evening, but sets by late evening. So you wouldn't want to wait too late to view it. The nearer it gets to the horizon (as it begins to set) the more distorted it will be due to the thick atmosphere.

5. ## Re: New and Excited!! :)

Hi and welcome to the forums!

Congratulations on your new scope and the great views you have already managed!

You already have a decent spread of eyepeices, so use them and see what works and what does not before buying anything new.
Most of all have fun and continue to enjoy this addiction called astronomy!

Cheers
Last edited by kingclinton; 04-10-2014 at 05:45 AM. Reason: spelling blunder

6. ## Re: New and Excited!! :)

Howdy Charley. Welcome, and immerse yourself in the limitless amount of knowledge available here. I'm having the same impulses. Got to get more power etc. Trouble is, I know nothing yet but am slowly picking up info. Way I look at it, darn near 60 years before I picked up a scope and got the bug. Another few weeks aint going to matter. I'm just looking and learning. Have fun dude.

7. ## Re: New and Excited!! :)

Welcome to the forum and congrats on your new scope!

8. ## Re: New and Excited!! :)

Welcome to the hobby and the forum.

I agree that M42 (Orion Nebula) should be next, as it's about to literally "go south" for the summer very soon. Catch it while you can.

Clear Skies

9. ## Re: New and Excited!! :)

Welcome Charley and congrats on the new scope - great use for a tax refund!

I agree that a 5x Barlow is not a good investment. A variable polarizing filter will help with brighter objects and a solar filter will give you something to do in the daytime.

10. ## Re: New and Excited!! :)

I have found absolutely no use for even a 3x barlow in my 60 years or so in this hobby much less a 5x barlow...Please do your self a big favor and stick with the 2x barlow....

This hobby is NOT about magnification...(that is the game played with microscopes not telescopes) its all about gathering as much light as possible and you will quickly learn that you will seldom go over 100 to 200x even on good nights....

I would use the eyepieces you got with the scope for a few months .... Then start thinking about buying another eyepiece... until then start looking for a chair

Bob G

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