I need some info

[Rick King]

I recently bought a Celestron astromaster 130 EQ MD. There was a doubler in with it. What do you use the doubler for? I've tried to use it, but failed miserably. 

[ronin]

Guess you mean a 2x Barlow. Simply it doubles the effective focal length of the scope, does this by a negative lens that produces a image that is twice as large.

Set up is usually Focuser, then Barlow, then Eyepiece.

If you use a short eyepiece then there is the probability that the total magnification is too great.

Unless good theey can drecrease to quality of what you see.

Need to check on the exact design of the 130 EQ MD scope. One design already has a barlow built in, if yours is such then do not bother to use the seperate item.

OK, yours is fine, it is 130 f/5 and not a Bird Jones design.

[LukeSkywatcher]

By "Doubler" do you mean a 2x barlow lens?. If so, it doubles the magnification of any eyepiece you use with it, so say a 10mm eyepiece when used with 2x barlow becomes a 5mm eyepiece. 

How to use it.........in this order:

scope>diagonal>2x barlow>eyepiece>eye

[Cornelius Varley]

On ‎3‎/‎12‎/‎2017 at 20:29, LukeSkywatcher said:

By "Doubler" do you mean a 2x barlow lens?. If so, it doubles the magnification of any eyepiece you use with it, so say a 10mm eyepiece when used with 2x barlow becomes a 5mm eyepiece. 

How to use it.........in this order:

scope>diagonal>2x barlow>eyepiece>eye

The Astromaster doesn't require a diagonal. So the sequence is focuser > barlow > eyepiece.

[Cornelius Varley]

On ‎3‎/‎12‎/‎2017 at 20:21, Rick King said:

I recently bought a Celestron astromaster 130 EQ MD. There was a doubler in with it. What do you use the doubler for? I've tried to use it, but failed miserably. 

The "doubler" , barlow lens increases the focal length of the telescope. Is this case the 2x barlow doubles the focal length of the Astromaster 130/650 to 1300mm. This means that any eyepiece inserted into the barlow doubles the magnification of the eyepiece. The 10mm eyepiece together with the 2x barlow will result in 130x magnification (1300/10) and the 20mm eyepiece 65x magnification (1300/20). Without the barlow the eyepieces give you 65x and 32.5x magnification respectively.

[Rick King]

There's no lens in my Barlow. It's just a hollow tube. Is there supposed to be a lens in it?

[Rick King]

I took it apart and the end that the lens is won't fit in my collar on my scope. Is the Barlow supposed to have a tiny hole in the black part that the lens is in?

[Dave In Vermont]

Can you take, or find a picture of this?

Dave

[Ricochet]

4 hours ago, Rick King said:

I took it apart and the end that the lens is won't fit in my collar on my scope. Is the Barlow supposed to have a tiny hole in the black part that the lens is in?

Is the black part a little bit wider than the silver part of the barrel and maybe a bit rubbery? If so you're looking at the lens cap. Pull it off to reveal the Barlow element beneath. If you can already see the lenses from the bottom end of the Barlow this isn't the problem. 

[Cornelius Varley]

6 hours ago, Rick King said:

There's no lens in my Barlow. It's just a hollow tube. Is there supposed to be a lens in it?

The barlow lens should probably look like this one https://www.firstlightoptics.com/barlows/celestron-2x-universal-125-barlow.html The black ring at the bottom retains the lens assembly.

[Alan64]

Hello Rick, and welcome,

Is this your kit?

https://www.bhphotovideo.com/bnh/controller/home?O=&sku=545212&gclid=CjwKEAjwzKPGBRCS55Oe46q9hCkSJAAMvVuMgEdQkWO1EaZNy2RNdoYvOozXlp1u3ECAvuG2mfQ_uxoC1mHw_wcB&is=REG&ap=y&m=Y&c3api=1876%2C92051677682%2C&Q=&A=details

If so, a 2x barlow did not come with your kit.  

The specs for your kit state that it comes with this...

Is that what you're referring to?  If so, that's not a 2x barlow, but simply an erect-image 20mm eyepiece that will give you a power of 33x, and a pretty good power for observing large objects, like the Moon.  

These are barlows, which will double and even triple the power of any eyepiece, and in helping to observe smaller objects up close...

If you'd like to have a good barlow, and maybe an eyepiece or two, or three, along with it, Agena Astro offers a very good selection, at great prices and with free shipping on all orders $10 and up...

http://agenaastro.com/gso-1-25-2x-achromatic-barlow-lens.html

I got my barlows, pictured above, from them, too, along with a few eyepieces.

A few inexpensive Plossls would be a great addition to your kit, and for an improved observing experience.

Your 5" f/5 Newtonian has a focal-length of 650mm.  To find the power that a given eyepiece will offer, simply divide the focal-length of the telescope by the focal-length of the eyepiece.  For example, your kit comes with a 10mm eyepiece...

650mm ÷ 10mm = a power of 65x

If I had your telescope, I would choose, in addition to the barlow, these Plossls...

http://agenaastro.com/gso-32mm-plossl-eyepiece.html (20x), and for your lowest power in helping finding objects to observe.  Once you find an object of interest, then you can swap out the 32mm with this 12mm(54x) for a closer look...

http://agenaastro.com/gso-12mm-plossl-eyepiece.html

You can then 2x-barlow the 12mm for a simulated 6mm(108x), and for an even closer look.  You can also 2x-barlow the 32mm for a simulated 16mm(41x).

This wide-field 20mm(33x) would be a big improvement over the  20mm erect-image that came with your kit...

http://agenaastro.com/gso-20mm-superview-eyepiece.html

Understand that the manufacturer, generally, is going to give you a good telescope for the price, but the eyepieces that come with the kit, and other accessories that may also be included, are not so good.  They're only intended to get you started, and at the barest minimum; the ground floor.

Now, a 5" aperture is theoretically capable of providing a power up to 250x, but realistically, in actual practice and use, the atmosphere and the optical quality of the telescope tend to limit that upper power to about 150x or so.  Let's see what would be needed for 150x then...

650mm ÷ 150x = a 4.3 eyepiece, or an 8mm or 9mm combined with a 2x barlow...

http://agenaastro.com/gso-9mm-plossl-eyepiece.html (72x), and when 2x-barlowed for a simulated 4.5mm: (144x)

That's one 2x barlow, three Plossls, and for six different powers...

...20x, 41x, 54x, 72x, 108x, and 144x.

It's like having six eyepieces for the price of four.  Barlows are very useful in that regard, and in extending a useful set of eyepieces.

Do not choose eyepiece sets offered by Celestron or Meade.  It's best to build up a set of eyepieces instead, to get your money's worth, and eyepieces of better quality.

With the wide-field 20mm in addition, you'd have a wider view at 33x, and 65x when the 20mm is combined with the barlow.

 

Your telescope is a Newtonian, and therefore may or will need to be collimated upon its arrival after its long and bumpy ride from China, and occasionally as you use it in future...

http://www.schlatter.org/Dad/Astronomy/collimate.htm

http://www.forumskylive.it/Public/data/serastrof/201281510358_Astro Babys Guide to Collimation.pdf

Within those collimation instructions, you will read of a tool called a "collimation cap"...

http://agenaastro.com/rigel-systems-aline-telescope-alignment-eyepiece.html

The collimation-cap allows you to see the entire optical system inside your telescope, as shown here with the scene from my 6" f/5 Newtonian...

...and then to make adjustments as needed, and for best image quality.  The higher the power, the more precise the collimation(alignment) will need to be for sharp images at those higher powers.

In order to use the cap, the main, primary mirror will need to be center-spotted.  Look down the opening of your telescope and check to see if your main mirror is already center-spotted, like this...

...and please let us know, then we'll go from there.

[Rick King]

I finally figured out what was wrong with my Barlow 2X. It had a black lens cap over it. I wasn't pulling hard enough on it to separate it from around the lens. Thanks for all the help. Now I've got to wait on the sky to clear before I can give it a try. 

[Rick King]

Has anyone seen anything around the moon? I caught a glimpse of something last night that I haven't seen before. Is there any satellites going around the moon?

[Rick King]

Jupiter sure looks gr8 thru the Barlow now that the lens cap is off. Lol

[Alan64]

4 hours ago, Rick King said:

Has anyone seen anything around the moon? I caught a glimpse of something last night that I haven't seen before. Is there any satellites going around the moon?

I saw that myself.  It was Jupiter, and it was pretty close to the Moon; not quite an ideal planetary conjunction, but noticeable.

 

[Rick King]

I know I'm probably an idiot for asking this, but how do you use the setting circles? Do you line your scope up with Polaris and put your setting circles on zero?

[Art Gecko]

1 hour ago, Rick King said:

I know I'm probably an idiot for asking this, but how do you use the setting circles? Do you line your scope up with Polaris and put your setting circles on zero?

No, polaris' position in the sky is not 0:00:00 x 0:00:00 as you might expect, this is because Polaris is not exactly on the North Celestial Pole. To use the setting circles, first find the area of sky you want to observe and note what constellations are in that area. If you're not familiar with star names, a quick search online looking at star charts will give you the names and co-ordinates of the stars (star co-ordinates don't change, planets do!) pick a star and point your scope at it, centre it in the viewfinder... the declination axis should be fine but you'll then need to unlock and rotate the Right Ascension axis setting circle until the numbers read the same as the co-ordinates you got online... once you're happy that the numbers are accurate, you can use the setting circles to find fainter or harder objects in the sky by rotating the scope so the numbers match the co-ordinates of the object you want to view.

hope that helps, welcome and clear skies. Art

[Ricochet]

Try watching this https://m.youtube.com/watch?v=geQszAVWMok

[Cornelius Varley]

1 hour ago, Rick King said:

I know I'm probably an idiot for asking this, but how do you use the setting circles? Do you line your scope up with Polaris and put your setting circles on zero?

 

[Rick King]

What is the best telescope for around a thousand dollars that I can see saturns rings and them not be a blurr? This astromaster 130 EQ just ain't cutting it. I can see Saturn and it's rings, but with my ifone 6S+, all I see thru it useing my telescope is just an oblong glowing blob. I was looking at the celestron 8 inch. I want to be able to see nebula like the horse head, flame, and basically any deep space thing I can locate. The setting circles on my scope is just there for looks. They're useless. I want to learn to use circles just to know how to manually find something w/o a computer. My declination circle just spins around. It doesn't have a locking screw in it like the RA. Can anyone explain it as simple as you can? I'm not the brightest star in the sky when it comes to this. 

[cletrac1922]

I have never had any success using 2" 2 X barlow with a 1.25 eyepiece on my 10" dob

When purchased the scope, dealer advised better using a 2" barlow, than a 1.25 barlow

Never been able to focused

Using short shaft eyepieces

One of these days was going to try and do a collimation using my laser collimator with barlow attached

 

 

[Cosmic Geoff]

5 hours ago, Rick King said:

What is the best telescope for around a thousand dollars that I can see saturns rings and them not be a blurr? This astromaster 130 EQ just ain't cutting it. I can see Saturn and it's rings, but with my ifone 6S+, all I see thru it useing my telescope is just an oblong glowing blob. I was looking at the celestron 8 inch. I want to be able to see nebula like the horse head, flame, and basically any deep space thing I can locate. The setting circles on my scope is just there for looks. They're useless. I want to learn to use circles just to know how to manually find something w/o a computer. My declination circle just spins around. It doesn't have a locking screw in it like the RA. Can anyone explain it as simple as you can? I'm not the brightest star in the sky when it comes to this. 

A good quality 130mm telescope should give a decent view of Saturn's rings, as my 127mm Maksutov does. A larger telescope will give a slightly better view, seeing conditions permitting. But don't expect the kind of view taken by Hubble or space-probes.

iphone 6S+? - I think you are expecting far too much of a vary basic astrophotography experiment.

Horsehead nebula etc- forget it, these nebulae only show up in photographs.

Setting circles useless? You are 100% correct there. These circles are ornaments included as a sales gimmick. They only work on telescopes mounted in observatories, where the circles are the size of a bicycle tyre. Small circles cannot be set with the precision required to aim the scope at a circle in the sky only a few minutes of arc across, which basically is what you are trying to do. If you want something that works, buy a GoTo mount.

[rwilkey]

The setting circles on a small telescope like yours are just not accurate enough to give any meaningful accuracy in searching the night sky.  Your best bet is to learn the art of 'star-hopping' which will help you find the objects you want in the night sky.  You should be able to see Saturn as more than just an elongated blob with your telescope, use the focuser carefully to home in on the planet and you should get satifactory views of it including its largest moon Titan.  Good luck!